MedicinNews

Dec 20, 2008 at 15:27 o\clock

The general semiology

The general semiology At patients with a hypopituitarism the skin often loses a normal turgor and becomes waxy. Its rugosity, especially round a mouth and eyes is quite often observed, that prematurely ages the patient. Fatness usually remains, and the cachexia as which Simmonds originally considered as implication of this buy cheap levitra online disease, was, possibly, a consequence of a nervous anorexia. The moderate anaemia, usually , but sometimes hypochromia or macrocytic often develops. The most important factor of a pathogenesis of an anaemia is insufficiency of thyroid hormones though the certain role belongs, apparently, and to depression of secretion of Testosteron-Depotum, and also disturbance of production of erythropoetin. The hypopituitarism is accompanied by mentality changes, and the mental retardation or apathy were observed almost at half of the patients described Sheehan and Summers [110]. Paranoica psychoses concern other symptoms of disturbance of mentality and sometimes. At sick of a hypopituitarism without a diabetes in the anamnesis carbohydrate metabolism, as a rule, is not broken almost.

On the contrary, development of a hypopituitarism at sick of diabetes, requiring treatment by insulin, leads to the expressed depression of requirement for this hormone (often on 20-50 from an initial dose) and raises bent to hypoglycemic reactions. These changes remain even against full replaceable therapy by glucocorticoids that specifies in important role , and also adrenaline. Relative frequency of various implications of a hypopituitarism depends on the reason of this disorder. In publications of last years describe patients with tumours of a pituitary body which consider for today as the most frequent reason of a hypopituitarism. Though results of various observations and not completely coincide, but, apparently, before all and consequently secretion , and then Gonadotropinums is more often stops. Deficiency and meets less often and develops at later stages of disease. However possibility of existence monohormonal or selective failures sharply limits estimations of function of this gland by results of research of one-two hormones. The isolated hormonal buy online decadron insufficiency Quite often deficiency of separate hormones of a pituitary body can meet even without visible anatomic changes of a gland. Signs and symptoms of such conditions are described earlier. Insufficiency and Gonadotropinums cannot be distinguished clinically from primary depression of secretion of hormones of glands-targets whereas to differentiate insufficiency from primary adrenal insufficiency absence of a hyperpegmentation and predilection for the salty helps. There is the isolated deficiency which is illness of the childhood and youth more often. Localisation of primary disturbance at the isolated hormonal insufficiency of a pituitary body usually manages to be defined only at careful inspection of the patient. THE DIFFERENTIAL DIAGNOSIS The hypopituitarism can be confused with illnesses of two categories. The hormonal insufficiency caused by a primary hypofunction of peripheric glands or disturbances in that area which takes part in neuroendocrinal regulation (hypothalamus) concerns the first. The second covers the diseases having a number of general with a hypopituitarism of signs and symptoms, but not bound to a hypocrinism. Hypofunction of peripheric glands of internal secretion and hypothalamus The isolated insufficiency hormones should be distinguished from primary insufficiency of function thyroid, epinephral or sexual glands. As already it became perceptible, the semiology in these cases can coincide with hypopituitarism semiology completely. Last is especially difficult for differentiating from plural insufficiency of peripheric glands (for example, Schmidt's syndrome at which insufficiency of function thyroid and epinephral glands is combined). Last diagnosis can be assumed on the basis of signs diseases, presence of a diabetes, a moniliasis or a hypoparathyrosis and family character of this pathology. Though degree of hormonal insufficiency at a primary lesion of peripheric glands frequently more than at a hypopituitarism, it cannot serve as differentsialno-diagnostic criterion as possibility of incomplete insufficiency of function of a peripheric gland is not excluded. As characteristic sign for primary adrenal insufficiency the hyperpotassemia caused by depression of secretion of Aldosteronum serves. At a hypopituitarism Aldosteronum secretion remains sufficiently to prevent rising of level of a potassium in Serum. In these cases there is no also characteristic for illnesses a hyperpegmentation and requirement for salt.

Dec 20, 2008 at 15:27 o\clock

So, at a hypopituitarism

So, at a hypopituitarism Aldosteronum secretion though decreases, but to a lesser degree, than at primary adrenal insufficiency. There can be also a nausea, vomiting and a sharp hyperthermia. Sometimes owing to disturbance the hypoglycaemia, especially after long starvation and-or reception of moderate quantity of alcohol is observed. At patients order ultram prescription with isolated deficiency the hypoglycaemia can be a unique symptom of disease. Unlike patients with primary insufficiency of function of adrenals at which secretion is raised, at deficiency seldom there is a hyperpegmentation. Actually the depigmentation and depression of degree of sunburn can be observed even at a solar irradiation.

As secretion often drops out not completely, corresponding symptoms at patients can appear only during the stress periods (for example, at surgical interventions, traumas, serious infectious diseases), that for a long time complicates diagnosis statement. Disturbance of an egestion of water at the water load, observed at illnesses, meets and at insufficiency , but is expressed more weakly and often masks simultaneous insufficiency of a vasopressin (see further). The termination of secretion of adrenal androgens at men influences the general condition if function of spermaries is kept a little. However at women it can define depression and stars in a pathogenesis of abaissement of hair under mice and on a pubis. a hormone The conditions of thyroid insufficiency caused by depression of secretion , name secondary or a hypothyrosis. Clinical implications of a primary and secondary hypothyrosis, as a rule, do not differ from each other, except for gravity of a current. At patients with deficiency tolerance to a cold is broken, there are constipations, dryness and pallor of integuments, retardation of mental processes, a bradycardia and a rhonchial voice. The true myxedema becomes perceptible very seldom; infrequently there is also a hypercholesterinemia and a carotenemia. It can become perceptible both intensifying, and reduction of menstrual bleedings. Insufficiency arising in the childhood, leads to a sharp growth inhibition, refractory to treatment . At some patients with isolated insufficiency buy online pyridium observed a pseudohypoparathyroidism [108]. Luteinizing and follicle-stimulating hormones Deficiency of Gonadotropinums at women is shown by an amenorrhea and clinical signs failures, including an atrophy of mammary glands, a xeroderma and depression of secretion of a vagina that becomes frequent a cause of infringement of matrimonial relations. Can come and depression . At men abaissement of gonadotrophic function of a pituitary body is accompanied by reduction of the size of testicles which become soft and rather tolerant to pressure, and also symptoms of depression of production of androgens which depression and potencies, retardation of secondary growth of hair on corresponding sites of a body and animal force reduction concerns. The insufficiency of Gonadotropinums developing till the period of puberty or during this period, leads to full or partial absence of secondary sexual signs. At the isolated insufficiency of Gonadotropinums or at conservation of secretion absence of closing of epiphyseal zones caused by sexual steroids in long bones causes excessive growth of extremities that gives to the patient an eunuchoid kind. Growth hormone Disturbance of secretion at adults is not accompanied a little by appreciable clinical semiology. Though possesses distinct metabolic activity, but including of some compensatory mechanisms at abaissement of its effects masks clinical implications of deficiency of this hormone. At patients with deficiency tolerance to carbohydrates that is bound with is broken. However this condition sharply differs from a diabetes, first of all absence . takes part in healing of wounds owing to what it is possible to expect (though it and it is not proved), that at insufficiency the adnation of bones at fractures will demand larger time. Insufficiency at children is accompanied by a growth inhibition. At them the hypoglycaemia on an empty stomach which becomes a constant symptom at a combination to insufficiency [109] is often observed also. Prolactinum As unique clinical implication of insufficiency of Prolactinum absence of a postnatal lactemia serves. Vasopressin Absence of secretion of an antidiuretic hormone causes a syndrome , in detail surveyed in chapter 9. Kidneys lose ability water that leads to a polyuria and a polydipsia, and without augmentation of consumption of a liquid (that often meets at patients the confused consciousness) the serious dehydration can develop. Patients suffer from strong thirst which is satisfied with preferably ice water. At deficiency the polyuria can and not be shown, as glucocorticoids are necessary for an egestion of free water. Development of a polyuria in the course of carrying out of assay with or after the beginning of treatment by glucocorticoids serves as the weighty indicating on insufficiency of a vasopressin and . Oxytocinum Absence of Oxytocinum at the person is not accompanied by clinical semiology. At pregnant women with a panhypopituitarism patrimonial activity begins, and labours proceed normally, despite lacking this hormone.

Dec 19, 2008 at 18:24 o\clock

Though this method

Though this method (tibia-test) remains in the most reliable way of definition of biological activity , from a pituitary body, its sensitivity is insignificant (about 10 mkg), that does not allow to apply it to definitions of level in plasma. Besides, results of corresponding definitions are influenced by many other things factors that does the given cheap levitra way rather not specific concerning rasping extracts of a pituitary body. Till now there is no cytochemical technique of definition . Radio immunologic methods. These methods are standard for definition in organism liquids. Antibodies to are easy for receiving the person at a rabbit, and results of application of these methods in different laboratories will be compounded among themselves. Sensitivity of a method allows to define usually less than 10 , that more than it is enough for definition of initial levels of a hormone in circulation. Two-dimensional reactions with any another a hormone are absent, but practically all antibodies to find out two-dimensional reaction

with a placental lactogen which has very similar structure (see 7-7). Owing to rather high level of a placental lactogen at pregnancy usual radio immunologic definitions during this period appear unreliable. Radio receptor methods. The radio receptor method of definition of the person by means of plasmatic membranes of a liver of the doe-rabbits who are in the period of the middle of pregnancy is offered. Though this method also is less sensitive, than radio immunologic, but he allows to define maintenance in plasma. However it is insufficiently specific, as gives appreciable two-dimensional reaction with Prolactinum. The radio receptor method is applied to revealing of molecules with the changed biological properties which are present, for example, at an acromegalia [69]. Hormone level in a pituitary body and plasma Pituitary body. On share in a pituitary body of the person it is necessary buy decadron online approximately 2 of wet mass that makes 8-10 mg though modern methods and do not allow all hormone present at iron. Its maintenance at men and women almost equally and essentially does not depend on age. Every days than 5 , containing in a pituitary body are liberated less, and it is considered, that the appreciable part of a hormone is exposed to destruction in a pituitary body, at all not being . Plasma. Level in plasma of the adult person in rest on an empty stomach usually does not reach 2 ng/ml, and sometimes it appears below border of sensitivity of a method. At women maintenance a little above, than at men, and at physical work when it raises at persons of both sexes, this difference becomes more distinct. In the end of a pre-natal life and within the several first days after sorts level is very high (often above 50 ng/ml). Within several next weeks it sharply decreases, remaining hardly above, than at adults. Only very small part present at plasma is excreted by kidneys in immunologically taped form. Concentration in urine reflects its level in Serum, raises in the conditions of hypersecretion and decreases at a hypopituitarism, but diagnostic value of this indicator at disturbances of secretion is insignificant. Metabolic clearance and secretion From plasma mainly a liver and to a lesser degree kidneys. The period of semilife in Serum makes, 20-25 mines [70], and rate of a metabolic clearance - about 110 ml/m2 in 1 mines with small fluctuations at the conditions characterised by its superfluous or insufficient production [71]. At a hypothyrosis and diabetes found depression of rate of metabolic clearance . In this connection, except for the specified conditions, change of level in plasma precisely reflects change of rate of secretion of a hormone. At healthy men rate of secretion makes about 350 mkg/m2 a day whereas at women in this size reaches 500 mkg/m2 a day. Secretion regulation Secretion is regulated as rilizing - (STG-RF), and inhibiting () by factors of a subthalamic parentage. In normal physiological conditions both nervous, and other mechanisms of regulation of secretion become isolated, apparently, at level of liberation of one or both factors, instead of directly influence secretion at pituitary body level. As now liberation of these factors from a hypothalamus in vivo in physiological conditions does not give in to definition such liberation judge on their final effect - to change of secretion . The factors influencing secretion , are summarised in tab. 7-4. As initial concentration so often are near to the bottom border of possibilities of definition, for demonstration of brake effects simultaneous use of the stimulating agent quite often is required. The nervous. To the nervous stimulus influencing secretion , concern both physical and mental stresses, and the factors which defining its incidental secretion and have been not bound neither with stress, nor with visible metabolic changes that is more often registered at children and young faces, than at adults.

Dec 19, 2008 at 18:23 o\clock

The majority of these

The majority of these effects though and less expressed, it is possible to observe and at healthy faces. The mechanism of the specified changes widely studied by influence on the isolated tissues in vitro or by extraction and research of tissues through various time after hormone introduction in vivo. Many acute effects in the isolated tissues remind order ultram sale effects of insulin. In muscles and liver raises absorption of amino acids and their including in fiber. This process is caused by acute acceleration of translation preexisting , instead of synthesis of new molecules though last also is activated. In muscles and fatty tissue stimulates glucose absorption, activating process of the facilitated diffusion, and strengthens its recycling. In fatty tissue interferes with lipolytic action of catecholamins and stimulates synthesis and the squirrel. Except for fiber synthesis in the muscles, it is possible to show all these insulinoid effects at use of concentration of the hormone close to the physiological; such effects develop through 10-30 mines after addition of a hormone and are characterised by a phenomenon : through 3-4 after the occurrence the effect fades also it it is not possible to reproduce again by entering into system

of additional quantities of a hormone. Specific for it is possible to take out by means of the agents influencing synthesis or fiber. Simultaneously with disappearance of acute effects its late effects start to be shown. Them concerns 1 - acceleration of mobilisation of fat acids from a fatty tissue owing to intensifying of a lipolysis of triglycerides; 2 - sensitivity rising to lipolytic action of catecholamins and 3 - inhibition as absorption, and recyclings of a glucose owing to retardation of decarboxylation of a pyruvate. All these late effects remain within many hours, find out additivity at additional influences and form a basis of "diabetogenic" action of a hormone of growth on a carbohydrate and lipide exchange. Introduction renders on insulin secretion difficult and, apparently, three-phase influence. In the beginning there is an intensifying of secretion of insulin which is, possibly, direct effect on b-cells and can already be observed within 5 mines after an injection buy pyridium online both at healthy faces, and at patients with insufficiency of a hormone of growth [65]. During the subsequent 1-5 insignificant inhibition of secretion of the insulin which mechanism up to the end is not clear [66] is found out. After longer time more expressed and long rising of secretion which serves as implication not direct influence , and secondary reaction to disturbance of recycling of a glucose is observed. At long enough introduction , especially in the presence of other factors, such as glucocorticoids or corresponding genetic predisposition, the expressed diabetes can develop. After cancellation the described changes disappear, that specifies in absence of excessive damage of secretory ability ?-cells. Far not all effects observed after its injections by an intact animal, it is possible to reproduce at hormone influence on a tissue in vitro. Besides, though with membranous receptors of various tissues, including a liver, a mammary gland and blood monocytes, and it is easy to show linkage , but correlation of its biological effects with receptor linkage is less obvious, than concerning other hormones. That fact, that stimulates including of radioactive Zinci sulfas in a cartilage by means of an induction secondary the factor [67], has generated representation about presence at normal plasma of some STG-DEPENDENT the factors stimulating cellular processes of growth not only a skeleton, but also soft tissues. Subsequently the term for a designation of the intermediary of wider spectrum of biological activity [68] has been offered. This intermediary is rather similar and, possibly, is identical to the factor named [not suppressed (antibodies to insulin) insulinoid activity, soluble (in ethanol)] which represents a peptide with molecular mass nearby 7500, possessing many properties of insulin, including ability to contact insulinic receptors of fibroblasts of a chicken, and also showing dependence from and activity concerning a cartilage. , the most similar with , has received the name somatomedina. Are identified also fiber having more acidic reaction about the same size - somatomedin-with and a smaller peptide in the sizes (5400 dalton) - somatomedin-century After these peptides began to name (insulinoid factors of growth), that reflects their general biological properties. Now the role of these peptides in effects on secretion on a feedback mechanism, and also in effects most starts to clear up possesses many influences on growth of organs (causing, for example, a hypertrophy of heart and kidneys), and also on production and a metabolism of separate hormones (for example, Aldosteronum and renin production and thyroxine transformation in ). All these effects are more detailed are surveyed in other section. Definition Biological methods. In the beginning methods of definition were based on its ability to enlarge linear growth rats. Then more sensitive technique based on measurement of width of an epiphyseal cartilage of a tibial bone at of rats has been developed.

Dec 18, 2008 at 12:15 o\clock

This method is much more

This method is much more sensitive than others, and with its help it is possible to define a hormone in concentration of, and it possesses also fine specificity. However complexity of this method limits its application by frameworks of research problems. Hormone buy levitra online level in a pituitary body and plasma At a pituitary body of the person there are only small amounts : approximately. Maintenance in plasma of the healthy adult person fluctuates from less than 10 pg/ml (the bottom border of sensitivity of a radio immunologic method, according to the majority of laboratories) to. cosecretes incidentally and, besides, according to an accurate daily rhythm. The least level in plasma is registered by evening (20-23), and the greatest-early in the morning Dynamics of the maintenance of a hydrocortisone in plasma coincides with fluctuations of level , lagging behind from them on a small time interval. In the conditions of stress maintenance can exceed normal amounts in 10 times. Not all immunoreactivity] defined in plasma even by means of specific antibodies, is caused by monomer . In particular, at patients with malignant neoplasms the forms of this hormone having the big molecular sizes ("big" [20]) are taped;

Consider, that they are molecules-precursors. Metabolism Though it is selectively bound by a cortex of adrenals, but disappearance of a great bulk of a hormone from circulation is defined by other mechanisms, including intravascular enzymatic destruction. Rate of disappearance from plasma (the semilife period) varies depending on that, define a biological or radio immunologic method, and biologically active hormone disappears from plasma faster (the period of a semilife of 3-9 mines), than immunoreactive (the period of a semilife of 7-12 mines) . Considering rate of disappearance, equating distribution in tissues to distribution in extracellular space and accepting level in plasma for 25 pg/ml, it is possible to calculate, that rate of secretion makes 25 mkg/sut, i.e. Approximately 5 from its maintenance in a pituitary body. Secretion regulation In regulation of secretion there are three basic components: own daily rhythm ( 7-5), the closed contour of a feedback which reacts to change of level of a hydrocortisone in circulation, and an open contour the regulations, bound to set of the stimulus mediated by nervous system usually named . cosecretes pulsing flashes that reflects character of regulation of its secretion from nervous system. Daily rhythm can be observed concerning secretion as , and a hydrocortisone which levels reach a maximum approximately by time of normal awakening, and then gradually decrease to a minimum registered more close by midnight. The distortion of a normal cycle a dream - wakefulness involves respective alteration of daily dynamics of secretion . In this connection sensitivity of system a hypothalamus - pituitary bodies-adrenals buy decadron now to stimulation is highest late at night and lowest in the morning. The closed contour of a feedback in regulation of secretion is mediated mainly by a hydrocortisone which braking impact both on makes, and on a pituitary body. Stimulation of an axis a hypothalamus-pituitary body-adrenal which arises at depression of level of a hydrocortisone in circulation, depends both on the absolute maintenance of a hormone, and from rate of its change. Electrophysiological researches, and also results of studying of linkage of a hydrocortisone testify to probable existence both subthalamic, and extrahypothalamic places of short circuit of a feedback in which the hydrocortisone suppresses liberation factor Adrenocorticotrophinum-rilizing (). Besides, the hydrocortisone has braking an effect on a pituitary body, suppressing reaction on . Data available now do not allow to make the definitive conclusion concerning a comparative role central-nervous and a point of the appendix of action of a hydrocortisone on a feedback mechanism in physiological regulation of secretion . The open contour of this regulation includes various stimulus which keep within concept of physical or emotional stress, for example, a pain, a fever, alarm, depression and a hypoglycaemia. Inputs of all these stimulus, undoubtedly, are various, but all of them lead to liberation . Though any of similar stimulus concerning (some of them secretions of a hormone of growth and-or Prolactinum, for example, lead), but reaction are mediated by separate nervous ways and often arise for lack of reactions of others hormones. Hydrocortisone level in blood in very weak degree influences these reactions though at long introduction of the big doses of glucocorticoids they can appear suppressed, During the stress periods also daily fluctuations of secretion often disappear. Neuroendocrinal regulation of secretion was in more details discussed in chapter 6. b-LPG, AND RELATED PEPTIDES

Dec 18, 2008 at 12:14 o\clock

White mugs designate the

White mugs designate the subsequent updating carbohydrate lateral chains. The first proteolytic stage includes eliminating -LPG from the S-trailer site of the precursor; b-LPG can then turn in b-endorphine. Though b-endorphine contains amino-acid sequence and a met-enkephalin, production of this peptide in a pituitary body is not shown. The order ultram er proteolysis of the fragments remaining after eliminating b-LPG, leads to eliminating of the N-trailer site, which molecular mass depends on the maintenance in it of Saccharum, and to formation , which also is present in and (4500 dalton) forms Herbert and co-workers. - In. Martini L. Ganong Frontiers in Neuroendocrinology.-New York, Raven Press CORTICOTROPIN Action Main action renders on a cortex of adrenals where it stimulates secretion of glucocorticoids, mineralocorticoids and androgenic steroids. it is bound with specific, possessing with high affinity, receptors on membranes of cells of a cortex of adrenals and stimulates a steroidogenesis, accelerating cholesterol transformation in with the help the mechanism. stimulates also fiber synthesis that leads to a hypertrophy and a hyperplasia of cells of a cortex of adrenals. Extraadrenal effects Besides the influence on adrenals,

lipolytic an effect has on a fatty tissue, and also the hypoglycemic action carried at the expense of direct of effect on b of a-cell of a pancreas. Big doses stimulate secretion , accelerate transport of a glucose and amino acids in muscular cells and at animals interfere with hydrocortisone destruction in a liver owing to what the period of a semilife of this hormone in plasma is enlarged. If not to take into consideration patients with AkTg-sekretirujushchimi pituitary body tumours, it is very little probable, that level in plasma ever could appear sufficient for reproduction of these effects. For a long time influence on pigmentation is known. As as the agent causing a dispersion of melanin, is less effective, rather than a-MSG or b-MSG, was considered, that it accepts rather small participation in a pathogenesis of the hyperpegmentation observed in conditions, characterised by its appreciable hypersecretion, for example at illnesses and AkTg-sekretirujushchph pituitary body tumours (a syndrome of Nelson) . However in the light of recently received data about absence at the person both a-MSG, and b-MSG role can quite be larger, than it was supposed earlier. Really, even b-LPG can essentially strengthen pigmentation in the conditions of appreciable rising of its level in blood, for example at renal insufficiency (see further) . Definition Biological methods. In the beginning for. applied the methods assuming registration of changes of level buy pyridium now of Corticosteronum in adrenals, plasma of the venous blood which is flowing off from adrenals, or plasma of peripheric blood at rats or animals with pituitary body blockade. Sensitivity of definitions managed to be raised by working out of methods in vitro in which incubation V4 of a part of adrenals of rats in the beginning was applied, and later - the isolated adrenocortical cells in fresh culture. Though last system owing to difficulty of reception still is applied mainly in the research purposes, but it is sensitive enough for definition of those levels which are present at plasma of the healthy person . As in usual conditions hydrocortisone level in plasma is directly bound to level , hydrocortisone definition serves as very convenient way of biological testing at normal function of a cortex of adrenals. From the practical point of view, definition of level of a hydrocortisone in plasma, whether it be , or a radio immunologic method, appears less expensive and, as a rule, easier in the accessible way of an estimation of AKTG-FUNCTION of a pituitary body. methods. The method of radio immunologic definition in plasma was developed more longly, than corresponding methods for other hormones of a forward share of a pituitary body. It has been bound to some technical difficulties caused by low concentration in plasma, concerning weak antigenicity of this hormone and its susceptibility to destruction by peptidases present at plasma . Besides, existence of family of the peptides possessing partial structural (i.e. A heptapeptide), without the careful characteristic of an antiserum and the proof of its reaction with unique structural determinants left opened a question on specificity of a method of its definition. Despite all these difficulties, radio immunologic definition becomes more and more reliable and brings the increasing advantage in diagnostics and the control over treatment of separate disturbances of secretion of this hormone. Other methods. It is developed , or radio receptor, a method of definition in which partially cleared membranes of cells of a cortex of adrenals and which sensitivity are used it is almost peer to sensitivity of a radio immunologic method [18]. Technical difficulties of this method interfere with its application for routine definitions of levels in plasma. The graceful cytochemical method of definition [19] based on registration of densitometric shifts, enzymatically interfaced with caused maintenance depression in sections of adrenals of porpoises is described also.

Dec 17, 2008 at 06:40 o\clock

Concerning possible dependence

Concerning possible dependence of frequency of each of disturbances on a hyperparathyreosis aetiology there are limited data. The part of disturbances at treatment disappears. At a hyperparathyreosis observed linear communication order ultram hydrocodone soma between disturbance of informative function and augmentation of level of calcium in Serum. In 30 of patients find out a depression, and hyperparathyreosis treatment is accompanied by some signs of improvement of a mental condition of patients. Disturbances of function of nervous system serve as classical implication of a thyroid pathology. At sick of a hypothyrosis weakening of storing and concentration of attention becomes perceptible. In serious cases dominating rhythm is slowed down. It is established, what exactly the first improves the functions after the beginning of replaceable therapy. Similar disturbances are described and at a hyperthyroidism.

Unlike disturbances of informative function, character of disturbances of emotional sphere, apparently, is bound to rising or depression of concentration of thyroid hormones. At sick of a hypothyrosis the suppressed mood dominates; for some it is characteristic behaviour. The main complaints sick of a hyperthyroidism are the raised condition, an emaciation and irritability; symptoms of serious depression are absent. Though the motor performance also raises, but such patients cannot be carried to a hypermaniacal category in the standard psychiatric sense. After liquidation of endocrine disturbances the mentality at sick both groups is usually normalised. The changes of mentality observed at patients with by diseases, generally are bound to the described changes of function of peripheric glands. Besides, loss often becomes perceptible. Replaceable therapy by corticosteroids liquidates the majority of observable shifts; depression introduction of sexual hormones. At replaceable therapy delicacy and apathy in which genesis the role of a hormone of growth and, possibly is possible, any others hormones nevertheless can remain. We do not discuss here effects of the hypoglycaemia caused by a hyperdysinsulinism as, strictly speaking, it does not serve as implication of hormonal influences on a brain. The behavioural disturbances bound and with a menstrual cycle are noted. Often describe a syndrome of a premenstrual strain which on a miscellaneous is shown at different people (for example, a headache, depression, a nausea and-or irritability). It was not undertaken Yet attempts to establish correlation of these symptoms with concentration of progesterone. Research of fluctuations throughout a menstrual cycle is given by changeable and a little reliable results. It is shown, that level monoaminoxidases (MAO) in plasma in a follicular phase of a menstrual cycle decreases. It is supposed (but it is not proved), that it can be in inverse relationship from rhythmic changes of level of catecholamins in a brain. buy pyridium High activity MAO accompanies also depression. Still there are no data about character of influence of steroids on level or activity MAO; in this respect it is possible to build only guesses. INFLUENCE OF HORMONES ON THE SEXUAL DIMORPHISM OF THE BRAIN As well as concerning rodents, and concerning the person there are the data specifying that prenatal (person) or neonatal (rat) influence of androgens defines sexual differences in the brain organisation. Neonatal influence of androgens at rats (endogenous at males, exogenous at females) leads to formation acyclic (on man's type) to secretion Gonadotropinums and man's sexual behaviour. Females or the males who have received in the neonatal period estrogens, show female sexual behaviour and female character of secretion of hormones (the last is especially fair if estrogens enter to the gelded newborn males). For these effects there is a critical period as they are not observed if hormones enter in age [53]. Concerning a basis of these disturbances and hormonal factors responsible for them there is some question. The sexual dimorphism is established as with the help (for males of rats on areas is available less synapses, than at females), and research methods (electrophysiological researches testify that at intact males possesses communications with a tonsil of more cells projected on a hypothalamus, than at females or at the males gelded during the neonatal period; at the last frequency of categories of other neurones above, than at intact males). There are appreciable contradictions of what hormone defines effects neonatal [54]. These effects are not observed at introduction of dihydrotestosterone which is not exposed to aromatisation, but accurately shown at introduction of the androgens flavoured in an organism, and also at beta Oestradiolum introduction. At the rats receiving Testosteron-Depotum together with antagonists of estrogens, the syndrome neonatal is not shown. The brain tissue possesses ability to flavour androgens and consider, that effects of androgens are caused by their transformation into a brain as high level of a-fetoprotein in the neonatal period binds estrogens of mother and a foetus that interferes with possibility of their interaction with brain receptors.

Dec 17, 2008 at 06:40 o\clock

Though in this respect there

Though in this respect there can be some contradictions, that the definitive decision of a question on however is obvious, whether the sexual differentiation of a brain is caused by action of androgens or estrogens, depends on revealing and levitra nature decoding brain fibers in the neonatal period [55, 56]. In a brain of newborns the cytosolic fibers binding both estrogens, and androgens are found out. However the translocation such "receptors" in a kernel occurs in a brain of newborn males and the females who have received Testosteron-Depotum, but not in a brain of intact females and the gelded males. Besides, can prevent Testosteron-Depotum action, and progesterone introduction in the neonatal period interferes with implication influences as Testosteron-Depotum, and estrogens. Possible interactions of monoamines, hormonal effects on monoamines and concentration and-or affinities of receptors remain not up to the end studied.

At the person it is difficult to observe such early hormonal effects. The most suitable to this purpose are patients with a congenital adrenal struma. Other group is made by persons, whose mothers for pregnancy conservation received perorally Progestinums. In both these groups of the girl show lines of "man's" behaviour, than the girl from control groups is more often, and persons of both groups have essentially higher intellectuality factor (), than the population on the average. However if members of these groups to compare with , not exposed to fetally additional hormonal influences it appears, that all members of families of patients with an adrenogenital syndrome find out above the expected. This reservation does not concern persons, under the influence of synthetic preparations of progesterone [57]. At subsequent more extensive research the results which have not confirmed the statement have been received that excess of androgens makes positive impact on [58]. Patients of a female with a congenital adrenal struma (after treatment), no less than the females of primacies receiving in the period androgens, can find out cyclic secretion of Gonadotropinums and female sexual behaviour. There are also limited data concerning primacies and the person, specifying in sexual differences in the organisations of a brain shown in behavioural tests [59, 60]. EPIPHYSIS The epiphysis is formed in a kind diverticulums, of a roof of an intermediate brain. At the person order decadron the epiphysis contains cells of two types: , having a parentage and lost the photoreceptor function which is present at the lowest , and the modified glial cells. Cytoplasmatic processes terminate in perivascular spaces. The epiphysis closely contacts to a spinal liquid () a brain waterpipe. Whether cosecretes an epiphysis the products in - it is not known. Presence of epiphyseal hormones (see further) in plasma and urine, and also in the tissues deprived of enzymes of synthesis, explain secretion of products of an epiphysis in blood. SYNTHESIS OF EPIPHYSEAL PRODUCTS The epiphysis innervation possesses some unique features. It is almost entirely presented by the independent postganglionic fibers originating in the top cervical ganglion. These fibers form synapses on parenchymatous cells of an epiphysis. It is considered, that eisodic fibers to the top cervical ganglion originate or from bottom a visual tract, or from system communications. At the sympathetic nervous terminations of an epiphysis there is Noradrenalinum, and, besides, both in these terminations, and in , the serotonin is found out. It serves as the precursor of one of epiphyseal "hormones" . grasp a tryptophan, transforming it in 5-oksitriptofan and then in a serotonin. Serotonin transformation in demands two enzymatic stages; On the first of them the serotonin-N-atsetiltransferaza which transforms a serotonin into a N-N-serotonin, and on the second - oksiindol-about-methyltransferase () which transfers group on N-atsetilserotonin, forming participates. Activity is concentrated basically in an epiphysis though its presence is revealed and in other organs, such as a retina and a gland - small formation in an orbit of the person. Concentration of a serotonin, , serotonin-N-atsetiltransferazy and in an epiphysis is subject to circadian fluctuations. At rats the maximum level of a serotonin and both enzymes is reached during light day time and sharply decreases soon after darkness offensive when concentration , low in the daytime, starts to raise [61]. Communication of illumination, sympathetic nervous system both epiphyseal and hormones is presented on 6-9 [62].

Dec 16, 2008 at 08:48 o\clock

GONADOTROPIN-RILIZING the HORMONE

GONADOTROPIN-RILIZING the HORMONE () By means of immunologic methods decapeptide has been found out almost exclusively in a median eminence and a vascular organ and in smaller concentration in arched and kernels. With the help research methods it is possible to tap systems of the nervous fibers containing . Them order what is ultram it is possible to track to areas, an arched kernel and a vascular organ of a terminal plate. Other ways conducting, possibly, in a tonsil, knot of a bridle and mesh formation of a mesencephalon, could take part in behavioural effects . Concerning influence of a deafferentation on maintenance in a hypothalamus and out of it there are disagreements meaning that different researchers observed either depression, or its absence in a hypothalamus without change of level out of this formation; these disagreements are bound, possibly, with the different sizes of a subthalamic islet remaining after operation.

As well as concerning , the numerous analogues which part possesses larger efficiency are received, and others are its antagonists and can matter as a control device behind birth rate. As it was already mentioned, there is some uncertainty concerning existence of the second FsG-rilizing the factor differing from . Apparently, the majority of available data about different influence on secretion and do not contradict representation about a uniform rilizing-hormone and can speak difference of its doses, time parametres of reaction and interaction with steroid hormones pituitary body level. It is considered, that influence on secretion of L by a pituitary body is mediated by system adenylatecyclase-tsamf. Concerning possibility detection in plasma or urine there are appreciable disagreements. Dependence of reaction of Gonadotropinums on from sexual steroids varies, that is partly bound to used doses, and also a kind of animals. At the person short course of treatment by Oestradiolum reduces reaction of Gonadotropinums on . Unlike it long introduction of Oestradiolum strengthens this reaction. Short-term application of progesterone also reduces a gain of secretion of Gonadotropinums in reply to introduction . All these data are received at inspection of women. Introduction of estrogens to men considerably reduces reaction of Gonadotropinums on whereas the big doses of Testosteron-Depotum possess only easy effect. Reactance pyridium 100mg of a pituitary body in relation to at animals is enlarged under the influence of small doses of estrogens at females, but not at males whereas at the last Testosteron-Depotum oppresses corresponding reaction. Corticosteroids reduce reaction on . There are data that also raises secretion at some sick of an acromegalia. It was already mentioned behavioural effects . They consist in an induction characteristic for behaviour at the deprived estrogens ovari - and animals. Data of electrophysiological researches testify that fluctuations of activity of subthalamic neurones correlate with changes of secretion of Gonadotropinums and that introduction by means of a microelectrophoresis, apparently, essentially changes electric activity , but not neurones [9]. represents and, like another to hormones, has the shortest period of a semilife in plasma. the immunoreactivity] is found out in plasma [10], a spinal liquid [11] and urine [12] though its identity and is not indisputable. strong impact not only on secretion makes (at the person it blocks allocation in reply to all investigated stimulus, i.e. A hypoglycaemia, a dream, introduction L-dofa and an arginine), but also blocks secretion , insulin, a glucagon, a secretin, Gastrinum and a renin. It has caused searches of derivatives which could influence specifically only this or that hormone so that it was possible to receive specific therapeutic effects either at diabetes, or at an acromegalia and thus secretion of other hormones has not been changed. The mechanism of oppressing action on secretion is unknown, though this effect can be mediated by production depression . It is known, however, that all influences on secretion of hormones are accompanied by change of streams of calcium therefore absorption of calcium by cells is braked; action manages to be prevented addition of calcium [13]. The greatest quantity contains in a median eminence (tab. 6-1 see), but appreciable concentration are present and at other areas of a hypothalamus, no less than in a thalamus, a cerebral cortex, areas, an average and a spinal cord. The full deafferentation a hypothalamus leads to acceleration of growth and rising of level in plasma, but concentration in areas was not registered.

Dec 16, 2008 at 08:48 o\clock

Not clearly, whether regulation

Not clearly, whether regulation of secretion by concentration change or for the present hypothetical rilizing-factor (see further) is carried out assumed nejro-transmitteryaja. Besides, introduction brakes its own secretion. This effect could be mediated by concentration change or rilizing-factor , influencing a pituitary body, but could be defined and those changes of concentration which operate on the nervous factors regulating secretion . Rather buy decadron influences on a brain there are few given. Similarly and , at immediate application on certain population of single neurones both in a hypothalamus, and in other areas (such as a cerebral cortex and a cerebellum and the spinal cord) can lead to appreciable depression of frequency categories (14]. HORMONES WITH OBSCURE STRUCTURE KORTIKOTROPIN-RILIZING THE FACTOR () Though KRF-LIKE activity was the first of found out in hypothalamus extracts, its chemical nature is not established till now. Recently carried out researches testify that though can possess KRF-LIKE activity and the vasopressin, it is not identical to the substance which is present at extracts, received of a hypothalamus.

t is considered, that the vasopressin can subthalamic activity. Rats of line at whom the vasopressin is absent, keep ability to react to stress though in their hypothalamus contains less , than at animals of control group. It became perceptible, that from a hypothalamus of a pig has one peak with molecular mass approximately 1500 [15]. Studying of a hypothalamus of a rat has found out presence of two kinds - small structure with molecular mass nearby 1000-1500 and larger with molecular mass approximately 2400 [16, 17]. The substance possessing activity is found In the bull hypothalamus, with molecular mass nearby 1000 [18]; sheep has molecular mass more than 5000. Maintenance in defined a biological method. In one of works [19] it is informed, that its greatest concentration has been found out in a median eminence; smaller quantities contained in the areas located both above, and still smaller - in a visual hillock and a cerebral cortex. Concentration in a hypothalamus raised after a deafferentation, a hypophysectomy and dexamethasone introduction. Concentration at rats of line was essentially more low, than at control animals. However Yasuda and Greer [20] have found rather high concentration in a cerebellum, the big brain and a thalamus, and curves a dose-reaction in these departments differed from those concerning subthalamic . These authors have found out also the greatest concentration in a leg of a pituitary body and its buy avandamet big quantities in a back pituitary body, and curves a dose-reaction in the last besides did not coincide with that for a median eminence [21]. According to all publications, the vasopressin maintenance in investigated tissues was too small that though any share of activity could be carried into its account. Yasuda and Greer [22] did not observe changes of maintenance in a hypothalamus at hormonal shifts. On the other hand, rising of level in a hypothalamus through 2 4 mines after stress [23] became perceptible. Influence on secretion by a pituitary body is blocked by Cortisonum introduction just as thyroxine introduction blocks influence on secretion . It is supposed, that Cortisonum induces synthesis the squirrel. THE RILIZING-FACTOR OF THE HORMONE OF GROWTH Till now there are appreciable contradictions of chemical structure and the nature of rilizing-hormone . Data of the first report on allocation from extracts of a hypothalamus of a pig of decapeptide which, judging by results of biological definition, could cause secretion , were are considered by an artefact bound to procedure of an ex-traction. This peptide has appeared noneffective concerning emission immunoreactive in plasma of a rat and the person and, apparently, represented a part b-chains of pork haemoglobin. However nevertheless there are data about presence at extracts of a hypothalamus of substance which can influence secretion and, apparently, differing from a vasopressin and which also can cause secretion of this hormone. Though at a chromatography on a column from this substance elutes together with , unlike it is not blasted at an incubation with plasma. Yet it will not be possible to identify this substance and specific methods of its definition will not be developed, remains obscure, whether many stimulus and the agents causing secretion , by stimulation of liberation of its rilizing-factor or by allocation inhibition operate. THE FACTOR Existing data specify that the most part of the activity which is inhibiting secretion of Prolactinum and present at extracts of a hypothalamus, could be defined by Dofaminum.

Dec 14, 2008 at 17:32 o\clock

Various doses or volumes

Various doses or volumes of unknown assay investigate in the same system of observation, and variants of reaction both to an unknown preparation, and on a preparation of comparison or the standard analyze on parallelism and homogeneity of deviations. Last demand is obligatory for any definitions of hormones both in vivo, and in vitro. As example of biological system in vitro cells , or intersticial cells serve. Under the influence order ultram zoloft of stimulation cells synthesise and cosecrete Testosteron-Depotum in the quantity dependent on a dose of the stimulating hormone. By means of known techniques of [3] cells it is possible to separate from seed canaliculuses. These cells in regular intervals distribute on plates for cellular cultures and stimulate with various concentration of standard preparations and and various volumes of unknown assay. Testosteron-Depotum cosecretes in medium, and its concentration is defined by a specific radio immunologic method. At biological researches in vitro various indicators can be used; changes of concentration of steroids, enzymes or cyclic nucleotides concern them. Generally speaking, definitions in vitro are more sensitive, than definitions corresponding to them in vivo, and demand considerably smaller volumes of extracts of Serum, a tissue or urine. However at interpreting of results of biological research in vitro extra care as in such system the hormone can be biologically active is necessary, an in vivo to have very weak an effect.

This divergence reflects that fact, that the hormone should not only be bound to a specific site of a cellular surface and "start" certain sequence of biochemical shifts, but also to be delivered to corresponding cellular receptors in high concentration, to sate sufficient for reproduction of effect number of receptors. In some cases in force as if small updatings of structure of a hormone its clearance can change substantially. That the hormone has entered interaction with a receptor, it should be biologically active, i.e. To have corresponding conformstion for linkage by a specific receptor with high affinity or durability of communication. However the hormone can be biologically active in vitro, but not possess appreciable biological activity in vivo owing to the metabolic clearance changed because of the structural features. At research of biological activity in vivo and in vitro its essential divergences [4-7] are found out. After deprivation of molecule of sialine acid () in vitro the hormone renders same, if not larger, biological effect, as its native, completely a molecule [6, 7]. On the other hand, in vivo it shows very small biological activity reflecting degree of its molecule. This divergence is defined by much pyridium 200mg shorter period of a semilife in plasma in comparison with an intact hormone [5]. In this connection in vivo reaches the cells-targets in the concentration insufficient for reproduction of appreciable biological effect. Methods of definition of the same hormone in systems in vitro are usually more sensitive, than in systems in vivo. Some methods of biological research in vitro possess even larger sensitivity, than radio immunologic methods of definition of concentration of a hormone. Methods of biological research in vitro in which as an effect indicator specific receptor linkage or adenylatecyclase activation, and other biochemical processes are used not, usually in tens, and even hundreds times are more sensitive, than radio immunologic methods. Methods of biological definition of hormones in vitro are not included now into number of routine ways of an estimation of a condition of the patient, except for those rare cases when it is possible to assume a divergence of biological and immunologic activity of a hormone. CYTOCHEMICAL BIOLOGICAL RESEARCHES These methods represent variants of the described biological researches in vitro. They usually possess larger sensitivity, than radio immunologic methods, but roads are much more bulky also at calculation on one definition. Results of cytochemical biological researches quantitatively estimate on microscopic sections by means of the special device - a microdensitometer. Microscopic sections prepare from tissues specific to a given hormone or cells-targets, before for influence of different concentration standard and the examinee of a hormone. By means of a densitometer scan area in diameter of 250-300 nanometers for a quantitative estimation of the colour reaction caused by change of a redoks-condition of object under the influence of hormonal stimulation. For the quantitative analysis use the histological stains sensitive to these changes. The first system of cytochemical biological research has been developed for , and as a target tissue the cortex of adrenals served in this system [8]. Other ways of biological definition either are too insensitive, or demand great volumes of plasma. Thus, cytochemical definition of a redoks-condition of a tissue is a valuable agent of the analysis of the normal and changed function of system hypothalamuses-pituitary bodies-adrenals on level . The cytochemical method of definition and L is developed, but there were the essential difficulties bound to appreciable fluctuations of results of different definitions and changeable sensitivity of object, that, probably, reflects known biological divergences at different animals [9].

Dec 14, 2008 at 17:32 o\clock

Sensitive specific cytochemical

Sensitive specific cytochemical methods are offered for parathormone definition, BP and Thyrotropinum [10, 11]. At the further complicating of the equipment which will allow to enlarge number of researches in one definition, this method can find wider application. It is especially attractive because does not demand use of radioactive bonds. Cytochemical methods are rather narrowly applied in clinic and used basically as a sensitive way in scientific researches. RADIO IMMUNOLOGIC METHODS Radio immunologic methods now, are possibly, most widely applied to quantitative definition of hormones and many decadron other things bonds in biological liquids. As shows the name, the radio immunologic method represents immunologic research in which use labelled hormones or antibodies binding them. More 20 years ago Berson and Yalow [26] have offered a radio immunologic method of definition of insulin. This method was based on their observation according to which in peripheric blood sick fiber (which as it has been shown later is present diabetes, receiving insulin, is globulin), binding insulin, 131I Value of these data and the subsequent working out of a radio immunologic method of definition of insulin is underlined by award Yalow and Berson the Nobel Prize. Soon after the first reports of these researchers other laboratories had been developed and described corresponding methods for definition of other hormones. In these methods the serumal fibers binding a certain hormone or and carrying radioactive label-hormone, competing to a standard hormone or a hormone which is present at biological assay are applied either antibodies, or. antigen and antibody interaction can be surveyed as reaction of the pseudo-first order which schematically can be presented as follows Reaction an antigen-antibody is reversible, but rate of dissociation of a complex an antigen-antibody is much less, than rate of its association.

The quantity of a hormone bound to an antibody, is a resultant of rates of association and dissociation. As in each test tube bring constant concentration of antibodies and a labelled hormone, quantity of the impulses bound to antibodies, should depend on concentration of not labelled hormone added in the form of the standard or unknown assay. The above concentration of not labelled hormone, the smaller appears quantity of the impulses bound to antibodies, present at system in the fixed concentration. On 5-1 various often applied ways of a graphic representation of results of radio immunologic researches are resulted. The top schedule the dose-reaction in logarithmic co-ordinates where on an axis of ordinates the number of impulses of the hormone bound to antibodies is postponed, led to the maximum number of the bound impulses (In), when only antibodies and a labelled hormone (without not labelled) represents a curve. This construction in system logit-log co-ordinates usually represents a straight line that facilitates visual interpolation of quantity of a hormone in avandamet unknown assay. For the purpose of reception of the straight line facilitating visual interpolation of quantity of a hormone in unknown assays, apply various ways of transformation of data. The majority of results of radio immunologic definitions is exposed to the machining, allowing to avoid tiresome and long calculations. Reception of high cleaning hormones has given the chance to develop sensitive radio immunologic methods for exact measurement of low physiological levels of the circulating hormones, demanding concerning small volumes of biological liquids. For sensitive radio immunologic definitions it is necessary following 1 - the high cleaning hormone carrying a radioactive label with enough high specific activity that it was possible to bring in each test tube only its quantities; 2 - the reactants used in reaction of joining of a label, should not change a hormone immunoreactivity] in essential degree; 3 - antibodies with enough high sensitivity (affinity) and specificity to define low physiological levels of the necessary hormone; 4 - a corresponding preparation of comparison in relation to which it would be possible to interpolate unknown concentration of a hormone in unknown assay. The preparation of comparison and investigated hormone should co-operate equally with antibodies and give parallel curves a dose-reaction. In reliable systems for radio immunologic definition concentration of a labelled hormone and antibodies is fixed. In this connection in process of augmentation of concentration not labelled the hormone decreases probability of linkage of a labelled hormone with antibodies that causes a return parity between number of molecules of the labelled hormone bound to antibodies, and concentration of not labelled hormone in a reactionary admixture. Concerning interaction of an antigen with antibodies some allowances 1 - a present hormone are accepted and co-operates with antibodies with peer affinity irrespective of, it contains a radioactive label or not; 2 - present antibodies and one molecule of an antibody co-operates with one molecule of a hormone; 3 - two different kinds of molecules - a hormone and antibodies - react until between them balance will not be established; 4 - the effective remedy of separation bound to antibodies and a free hormone is applied, and the technique of separation does not break the initial balance reached between a hormone and antibodies.

Dec 13, 2008 at 07:53 o\clock

It has been established, that the component

It has been established, that the component In specifically contacts a chromatin of cells and can define specificity of fabric linkage activated a receptor [84]. Receptors of androgens have been identified in man's genitals and sexual tissues in researches on linkage Testosteron-Depotum and dihydrotestosterone. The receptors of androgens which are present at cytoashes of a prostate, seed blisters and other man's tissues, as 8-9S- at low ionic force and as 4S-forms in the presence of salt. Like receptors of estrogens and progesterone, cytoplasmatic complexes are exposed to a translocation dependent on temperature order generic ultram in a kernel, whence them it is possible in the form of the 3S-form [85]. The important feature systems in man's sexual tissues is necessity of transformation of Testosteron-Depotum for the dihydrotestosterone, previous linkage with a receptor and its translocations. Thus, 3S-nuclear the complex in these tissues contains not Testosteron-Depotum, and the dihydrotestosterone formed under the influence of 5 -reduktazy to linkage with cytoplasmatic receptors. Necessity of enzymatic transformation of androgenic hormones for dihydrotestosterone for activation of receptors in many man's target tissues concerns some forms of genetically determined resistance to androgens.

The syndrome of testicular feminization - the extreme form of a man's pseudohermaphroditism can be caused both disturbance of synthesis of dihydrotestosterone, and receptor defect at action of androgens. The similar syndrome at rodents (Tfm) is defined by defect receptors, instead of disturbance of restoration of Testosteron-Depotum in dihydrotestosterone [86]. Glucocorticoid receptors have originally been found out in hepatic and lymphoid cells, and now are opened in the majority of tissues of mammals that will be compounded with representation about widespread influence of a hydrocortisone and related corticosteroids. For lack of a steroid receptors are astable and show high affinity and stereospecificity to natural glucocorticoids and their active synthetic analogues, such, as dexamethasone and . Like another to complexes, the gljukodjurtikoid-RECEPTOR complex is exposed to fast temperature activation with ability acquisition in a kernel and to contact a chromatin. The Glucocorticoid-RECEPTOR complexes as 7S-forms at low ionic force also turn to the 48-form at high ionic force. Activation a complex does not change it properties, but causes depression of an isoelectric point, that causes mobility change on ion-exchange mediums ( and DEAE-CELLULOSE), and also affinity rising to DNA and a chromatin [87]. Such changes of ionic properties allow to part the activated and not activated complexes on DEAE-CELLULOSE. The analysis cells of a thymic gland by means of this technique has shown, that not activated complexes are present only 1st minute after influence pyridium by dexamethasone, and within next several minutes quickly turn in activated [88]. receptors have been found out in target tissues of mineralocorticoids, such, as kidneys, a bladder, a parotid gland and an intestine. In a secretory epithelium such receptors extremely and hardly give in to the analysis, and their studying becomes complicated presence at target tissues of other receptors for structurally and biologically similar glucocorticoids [89]. Comparative affinity of two classes of receptors to Aldosteronum and glucocorticoids is that, that Aldosteronum in low and physiological concentration mainly contacts I () type of binding places, and in higher concentration with the increasing quantity of glucocorticoid receptors. And on the contrary, glucocorticoids in physiological concentration are deprived activity, but in superphysiological quantities (endo - or exogenous) contact I type of receptors and render action [73]. At research by means of a technique, allowing to level an intervention of glucocorticoid receptors, it has appeared, that receptors bind mineralocorticoids according to their biological activity and react with a hydrocortisone (at enough high concentration of the last), no less than with more active steroids - Aldosteronum and a cortexone, Main cytoplasmatic complexes as 8,5S-forms at low ionic force and as 4S-forms at high ionic force [90]. Nuclear receptors, 0,3 M l, also as 48-forms also are exposed to the maximum translocation from through 10 mines after Aldosteronum injection. Influence of steroids on a receptor: activation and linkage by a kernel Steroid hormones of any of the basic classes including estrogens, Progestinums, androgens, glucocorticoids and mineralocorticoids, operate according to the general scheme, i.e. Are bound to specific cytoplasmatic fibers, or receptors then there is an activation of a complex and its translocation in a kernel. Here complex linkage by nuclear acceptor sites of a chromatin of cells-targets modulates activity of the specific genes responsible for synthesis of certain kinds ( 4-26). As already it became perceptible, any cytosolic complexes of a steroid with a receptor are exposed to the conversion induced by a hormone named activation of a receptor which causes their accumulation and linkage in a kernel. Process of activation of a receptor is induced by a hormone and depends on temperature; it includes usually change of the seeming molecular mass, a charge or conformstion of a complex. However there are no constant changes which would characterise activation process to all classes of steroid hormones.

Dec 13, 2008 at 07:52 o\clock

Augmentation of rate of a sedimentation

Augmentation of rate of a sedimentation with 4 to 5S find out only receptors. and some complexes after activation reduce rate of a sedimentation, and glucocorticoid receptors do not change it, but find out charge change. Though process of "activation" of receptors of steroid hormones is necessary for nuclear linkage and action, it varies for separate steroid receptors, and its general basis remains obscure. Agonists and antagonists of steroids As well as types biologically active , whether it be medicinal substances, transmitters or hormones, buy cipro xl steroid hormones and their derivatives it is possible to part many other things on agonists, antagonists and inactive bonds. Activity of agonists is proportional to affinity of their linkage with receptors and efficiency of activation of biological reaction a complex. Antagonists also find out high affinity to a receptor, but do not contact a kernel or do not possess ability to activate nuclear processes. The allosteric model of action of steroid agonists and antagonists on conformstion and activity of receptors is resulted on 4-27. It is important to underline, that differences between agonists and antagonists seldom happen absolute and that many bonds operate as partial agonists (or partial antagonists), contacting receptors and, even at full saturation of receptor sites, not causing the maximum reaction.

Pure agonists can be weak "or" strong depending on their affinity to receptors, but they do not operate as antagonists. So,"weak"agonists can cause the same biological reaction, as"strong"if are present at concentration, enough high to sate the same share of receptors. Unlike it, partial agonists cannot cause full reaction, even sating the majority or all receptors, and then can make opposing impact or block effects of added bonds-agonists. Partial agonists can be surveyed as the substances taking a certain place in a spectrum of activity between pure agonists and pure antagonists. For the majority of the clinical and experimental purposes it is better to use pure agonists and antagonists. However many antagonists possess some degree of activity of an agonist that it is necessary to consider at their application for treatment and at the analysis of receptor linkage. It is necessary to notice also, that if activity buy generic rimonabant of the given agonists in various tissues is rather constant, partial agonists and antagonists can show changeable and opposing activity in separate target tissues or in different experimental conditions [69]. Antagonists of estrogens Some nonsteroid analogues of estrogens, such as and Tamoxifenum, interfere with implication of reactions caused by estrogens: growth of a uterus and a hyperplasia of cells-targets. Such substances contact cytoplasmatic receptors and stimulate a translocation a complex in a kernel. Here the complex contacts a chromatin and is late for the long period, causing initial stimulation RnK-polimerazy and a cellular hypertrophy. However linkage the antagonist-receptor of a complex is not replaced by the subsequent restoration of number of cytosolic receptors, whether it be at the expense of repeated cycles or their resynthesis that is observed after a translocation of receptors under action agonists [91]. Antagonists of androgens The most active natural antiandrogen is progesterone, and some of the most powerful antagonists of androgens represent active derivatives. Antiandrogens counteract effects of Testosteron-Depotum or dihydrotestosterone, competing for sites of the receptors which are present in target tissues. Such bonds have the potential importance in treatment of a hirsutism and others syndromes, and also in treatment of a hyperplasia and a prostate cancer. Highly active antiandrogens, such as a tsiproteron-acetate, co-operate with , no less than with , receptors. However not all Progestinums are antagonists of androgens, and hlomadinon-acetate possesses concerning low antiandrogenic activity, despite its close structural similarity to a tsiproteron-acetate. Presence of tsiklopropa-new group at a ring And tsiproteron-acetate is its basic structural difference from hlomadinon-acetate and can play the important role in definition of antiandrogenic activity [92]. Some antiandrogens suppress also gonadotrophic secretion with the subsequent depression of production of Testosteron-Depotum, no less than blockade of action of androgens. oppresses also activity 5 -reduktazy, breaking thereby formation . It is important to notice, that some antiandrogens possess also other kinds of hormonal activity, for example tsiproteron-acetate shows not only androgenic, but also and antigonadotrophic properties. Besides, long treatment for achievement of antiandrogenic effect can lead to suppression of function of adrenals at the expense of inhibition of secretion , possibly, through the central mechanisms of liberation of Adrenocorticotrophinum.

Dec 12, 2008 at 07:50 o\clock

This so-called binding

This so-called binding fiber can represent one more the factor in system of a homeostasis of calcium or be another enzyme or, probably, the general binding enzymes. Rather small quantity of this fiber which is present at a brain, specifies in order buy ultram online a high probability of its functioning as enzyme or . Interaction between calcium and cyclic nucleotides Collects more and more data about some interactions between calcium and the cyclic nucleotides, reactions of a feedback framing a network with which help two alarm systems regulate activity each other ( 4 18).

3 between and calcium are sectioned into two types according to their role in quality of one-or two-controlled control systems in separate target tissues (30). One-controlled systems are the systems which are present at cells, regulated by one stimulus where only simple regulation of type "including-deenergizing" depending on presence or absence of stimulus functions. In different kinds of cells as the second mediator calcium or and if it is formed it strengthens a calcium signal can operate. To tissues in which one-controlled control systems function, the nervous tissue, a cerebral layer of adrenals, a forward share of a pituitary body, endocrine and exocrine parts of a pancreas, a cortex of adrenals, a bladder, sialadens and photoreceptor organs concern. In all these tissues cellular activity is regulated only in one direction (it is switched off ® is included), and activity stops after stimulus excision. In most cases the second mediator is, apparently, calcium, and indirect or strengthening an effect has on calcium effects. In the tissues supervised by hormones of a pituitary body (i.e. In adrenals, spermaries, ovaries and a thyroid gland), plays more important role as the second mediator, but besides operates in a close connection vpxl work with calcium that it is possible to observe at regulation of enzymes of a steroidogenesis and thyroxine secretion. Two-controlled control systems function in the cells regulated by two independent stimulus, for example when one stimulus "starts" cellular activity, and the second stops reaction, usually counteracting the first stimulus., As a rule, calcium serves in such tissues as a primary signal of 1st stimulus, and mediates effect of 2nd stimulus, modulating intracellular level of calcium. Thus, unlike a synergy between and calcium in one-controlled systems, in two-controlled effects and calcium are antagonistic. Examples of tissues in which last form of the control functions, smooth and warm muscles, melanophores, thrombocytes, mast cells and a liver are. In each of these types of cells activation is caused by rising of level of the calcium leaving intracellular stocks or arriving from the outside, and counteracting stimulus reduce the calcium maintenance in a cytoplasma at the expense of action . The liver and fatty tissue possess some lines of one-controlled systems as raises intracellular level of calcium and promotes unidirectional to effects of adrenaline and a glucagon. However insulin counteracts influence of these catabolic hormones, possibly, at the expense of reducing action on intracellular level , the core acting in a role of "the second mediator in this tissue. In more general case of two-controlled systems counteracting effects of calcium and are shown rather distinctly. Though it was supposed, as the cGMP counteracts effects , becomes more and more obvious, that cGMP level is often regulated by intracellular concentration of calcium and by that reflects effects of calcium, instead of is the primary antagonist . Data about dependence between activation of receptors and the subsequent changes in mobilisation of calcium and formation are summarised on 4-19. ACTION OF HORMONES AND METABOLISM Recently carried out researches in a scope hormones have shown, that membranous and products of their metabolism play the important role in reaction of cells-targets to hormonal stimulation. participate in operation hormones, at least, three basic ways 1) as a source of derivatives of arachidonic acid - precursors for synthesis of Prostaglandinums and related bonds with secondary effects on a target tissue; 2) at the expense of circuit acceleration and formations , influencing a cell-target metabolism (for example, a steroidogenesis); 3) at the expense of methylation rising , leading to formation from with the subsequent changes of fluidity of a plasmatic membrane and mobility of receptors in it. : structure, a metabolism and function Natural are derivatives of Glycerophosphatum or , containing two fat acids and the hydrophylic assistant, such, as a choline, ethanolamine, or a serine. They serve as the main components and cellular membranes and in a considerable quantity are present at a peripheric nervous tissue and a brain. possess the general structure ( 4-20), formed by an esterification of Glycerophosphatum with two fat acids and a hydrophylic component. The important feature is their ability to co-operate both with hydrophobic, and with hydrophylic domains and to occupy an interface between organic and water mediums. So, in they act in a link role between an albuminous part and a transported neutral lipid, and in a cellular membrane they form characteristic lipide which limits intracellular space. In a plasmatic membrane about 60 it is necessary on a share which is partially synthesised in the membrane by a methylation . and are present at smaller quantities, and assistants in different tissues vary on length and saturation degree. , or lecithines, are synthesised in animal tissues by three ways.

Dec 12, 2008 at 07:49 o\clock

During the basic way

During the basic way similar to those for synthesis , a choline , forming . Last is bridged with , turning in the TSDF-CHOLINE which reacts with at presence , forming . The second way of synthesis consists in an acylation (lecithin formed at hydrolysis ). At last, 3rd way having the especial relation to modern researches of hormonal influences on of a membrane, is reduced to a consecutive methylation in a cellular buy cipro 500mg membrane. These reactions in a schematic kind are presented on 4-21. Hormonal influences on a metabolism . Stimulation of formation of arachidonic acid and synthesis of Prostaglandinums. Many hormones raise production of Prostaglandinums a target tissue that is sometimes accompanied by secondary reactions of vessels and cells.

Though Prostaglandinums, apparently, do not play a role of mediators of action hormones, but stimulation of these formed fabric hormones at activation of cells-targets makes the important component of cellular reaction to interaction hormones with their receptors [57]. Prostaglandinums and related and are quickly synthesised by it from polynonsaturated fat acids-precursors, especially from arachidonic acid, at stimulation of cells-targets. Nonsaturated fat acids are present at a cell in a kind which to turn to substrate for a metabolism in Prostaglandinums and others active , should under action . On a share of arachidonic acid the greatest quantity of nonsaturated fat acids in fabric is necessary; This acid is exposed to a metabolism in two basic directions named cyclooxygenase and . The nearest products of a cyclooxygenase way are (G2 and 2) which turn to Prostaglandinums (2, F2 a and D2) under the influence of the enzymes wearing the general name , and also in (2 and 2) and (I2) under the influence of corresponding synthetases ( 4-22). Classification of these metabolites is bound to degree of their nonsaturation precursors; acid turns to products of 1st class (1, F1 a, TKA1, etc.), and arachidonic acid-in products of 2nd class (2, F2 a, 2, 2 and I2) [58]. and also are formed at the further metabolism , appearing during a cyclooxygenase way; they represent the important regulators of interactions of thrombocytes with a vascular wall. (I2) in considerable quantities it is produced endothelial and by cells of vessels where its formation is modulated by metabolites ways [59]. I2 is a highly active inhibitor of aggregation of thrombocytes, and its production is stimulated in endothelial cells with Thrombinum and braked low density. There are also the data testifying to a possible role of depression of ability of cells of vessels to produce I2 in development of an atherosclerosis. Later found out the way causes transformation of arachidonic acid in acids, including in acid () which then being blasted turns in acid (). These metabolites ways play an essential role in inflammatory reactions, including a chemotaxis of neutrophils and other consequences of activation of cyclooxygenase buy acomplia acomplia rimonabant rimonabant in thrombocytes and production I2 in a tissue of vessels. Recently obtained data testify also that metabolites of arachidonic acid can mediate action on liberation of hormones [60]. Any of the listed ways of production of active metabolites of arachidonic acid depends on adequate entering nonsaturated the precursor from membranous . Now it is known, that many forms of the activation of cells mediated by receptors are accompanied by rising of activity bound to membranes , which hydrolysis of ethereal communications in . It is Most important in this respect 2, splitting off fat acids in 2nd position which forms and nonsaturated fat acid, usually . quickly at the expense of carrying over activated fat acid that it is easily possible to measure on including of labelled arachidonic acid in cells. This circuit is a source of arachidonic acid for a metabolism on tsiklo - and to ways ( 4-23) also can influence permeability of a membrane and activity of other enzymes bound to a membrane [61]. Activation 2 depends on calcium; it occurs at stimulation of cells of adrenals that leads to circuit acceleration [62]. This effect causes also calcium 23187 and can reflect rising of intracellular level of calcium at action and secondary stimulation 2 as the early reaction accompanying AKTG-RECEPTOR interaction. It is known, that action on a steroidogenesis in adrenals depends on calcium, and not just from formation . At least, the part of requirements for a calcium for action can be bound with mediated A2 a circuit membranous at activation of a cortex of adrenals.

Dec 11, 2008 at 05:47 o\clock

MEDIATORS OF ACTION

MEDIATORS OF ACTION OF HORMONES THE GENERAL SKETCH: THE HYPOTHESIS OF "THE SECOND MEDIATOR Carrying over external (i.e. Extracellular) hormonal "signals" on internal medium of a cell after interactions it is carried out by "the second mediators which are formed at membranous level. The initial formulation of this concept belonging Sutherland, is shown on 4-2 where the general mechanism with order ultram online which help the hormones operating on a cellular surface, stimulate formation of "the second mediators is presented, such as . In the beginning this general scheme of action hormones on membranous receptors and adenylatecyclase has been offered on the basis of the researches spent with catecholamins, a vasopressin, a glucagon and , but then has been shown, that many hormones cause activation of adenylatecyclase and rising of intracellular level . However for some hormones, such as angiotensin, insulin and , the mechanism of activation of cells-targets remains obscure (tab. 4-1). Even in those tissues in which hormones it is considered to be actions the second mediator , the way to which one the system is broadcast in the whole spectrum of reactions of separate cells-targets is short clear. This question becomes complicated the dual nature of many and albuminous hormones which, on the one hand, are trophic factors with their late influences on growth and a differentiation of cells, and with another, act in a role of fast regulators of such cellular reactions, as a steroidogenesis and secretion of hormones.

The scheme of these slow and fast effects of the hormones rendering both late , and short-term metabolic influences [27], is resulted on 4-9. Communication between two specified aspects of action hormones is found out insufficiently full, and the majority of our knowledge of cellular reactions on interaction is based on results of research of acute effects hormones on their cells-targets. The intracellular alarm molecules, generated a hormone-receptor interaction, operate then on membranous and cytoplasmatic fibers, changing stages the systems supervising reactions of a cell-target. Is better the characterised mediators are and the calcium, acting in roles of intracellular transmitters and cells-targets resulting vpxl herbal a metabolism according to requirements for reaction to external stimulation by such factors, as hormones and others . If the calcium stimulus is provided with rising of concentration of calcium in cytoashes at the expense of absorption of calcium from an extracellular liquid or redistribution of intracellular calcium cyclic nucleotides are formed from and at the expense of activation the enzymes located in a plasmatic membrane and cytoashes accordingly. Thus, formation is immediately bound to saturation of receptors of a cellular surface and activation of the adenylatecyclase localised on an internal surface lipide of a plasmatic membrane. Unlike it, it is located mainly in cytoashes and it is not activated by immediately hormonal "stimulus". Calcium has the important an effect both on activity, and on destruction , and intracellular concentration of calcium serves, possibly, basic regulator of level and a cGMP in a cell [28]. The calcium role in interface of stimulus and reaction at activation and secretory processes has been established reliably enough. Subsequently, however, finding-out of widespread effects in quality of "the second mediator has caused the tendency to belittling of a role of calcium as intracellularly a regulator. Later value of interactions between cyclic nucleotides and calcium [29] has been shown, and again began to underline a primacy of this ion as a mediator of activation of many processes in cells-targets [30]. CYCLIC AMP As hormonal stimulation of cells-targets, as a rule, has intermittent and transient character, intracellular the second mediators should be exposed to a fast circuit (by destruction or entering in a new cycle) so that repeated and varying external stimulus could turn to strictly corresponding quantitative reactions of a cell. Dynamic balance between formation and cyclic nucleotides supervises their intracellular level in the condition of a cell initial and activated by a hormone and frames possibility of development of fast reactions to change of level of extracellular regulators. This regulation is mediated basically by adenylatecyclase activation in a cellular membrane that leads to augmentation of intracellular concentration . Rate of destruction also is object of hormonal regulation and can influence intracellular concentration of a nucleotide ( 4-2 see). All effects known for today in cells are realised through transformation inactive (protein kinases) in the active form, which specific albuminous substrates in a cell-target. Thus, the understanding of the mechanism of action hormones demands finding-out of ways of hormonal regulation of activity of adenylatecyclase and , and also ways of activation and functions of a tsamf-dependent protein kinase. Adenylatecyclase and its regulation Opening and adenylatecyclases group Sutherland has been bound to studying of regulation of a hepatic glycogenolysis by adrenaline and a glucagon [4]. These researchers have shown, that such hyperglucomized agents cause activation and the subsequent splitting of a glycogen to glucose phosphates.

Dec 11, 2008 at 05:47 o\clock

Then it has been shown

Then it has been shown, that activation depends on the intermediate stage (after identified as under the influence of a protein kinase) which is stimulated with the thermostable factor formed at interaction of a hormone with insoluble fraction of a hepatic cell. It has been established, that last reaction demands which in the buy cipro medicine presence of a hormone and a magnesium ion turns in and inorganic Natrii phosphas. Further it has been shown, that the enzyme responsible for this reaction, settles down on an internal surface of a plasmatic membrane and it is activated different by hormones ( 4-10). Named originally Sutherland adenyl cyclase enzyme of a plasmatic membrane subsequently began to name adenylatecyclase or . These terms describe its specific action on more precisely. The enzyme responsible for formation , it is necessary to name widest the common term "adenylatecyclase". After identification of adenylatecyclase as the enzyme bound to a membrane, and definition of its regulation from catecholamins and hormones there was a huge number of reports on participation (or nonparticipation) in a hormone-dependent processes.

It was soon found out, that ability to activate adenylatecyclase peptides and transmitters possess only, which contact a cell surface, whereas other hormones, (a thyroxine and steroids) do not render natural action on system adenylatecyclase - . Sutherland surveyed a cyclase as the enzyme possessing receptor (a recognition place hormones) and catalytic (transforming in ). Later it was supposed, that these exist in the form of the separate structures floating in lipide of a cellular membrane and united in the active form at interaction of a hormone with a receptor place [10]. This representation has laid down in a basis theories of activation of enzyme according to which the complex diffuses on a cellular membrane and co-operates with catalytic unit (activating it), the membrane located on a cytoplasmatic surface ( 4-3 see). This rather simple model of adenylatecyclase has become complicated subsequently, thanks to finding-out of a role of intermediate process (transduction) between interaction and change of conformstion catalytic , leading to enzyme activation. Existence buy rimonabant online and properties of this intermediate (interfacing) stage have been shown by group Rodbell in the course of studying the adenylatecyclase which are present at plasmatic membranes of cells of a rat liver [31]. On this system it has been shown, that guanylic nucleotides (especially ) strengthen activating action of a hormone on adenylatecyclase, and also dissociations of a complex of a glucagon with its receptor promote. Researches Rodbell testified that the glucagon facilitates adenylatecyclase activation by guanylic nucleotides, instead of renders direct stimulating influence on enzyme. the site of adenylatecyclase co-operating with a guanylic nucleotide, is identified in various tissues, and it is supposed, that he plays a fundamental role in operation hormones, catecholamins and Prostaglandinums. The subsequent experiments have confirmed the general dependence of action activating adenylatecyclase hormones from guanylic nucleotides, and value of linkage with a site as obligatory stage of hormonal action [12] has been underlined. The modern point of view on the mechanism of hormonal activation of adenylatecyclase as a primary stage of action a hormone assumes dependent from joining to to a site ( 4-4 see). Linkage with this intermediate fiber transforms inactive catalytic unit in its active the form; activation process stops at hydrolysis bound with formation , and enzyme restores the initial condition. In favour of existence of such mechanism data that activity stimulated with a hormone is bound with guapilnukleotid-reguljatornym a site testify, and also about ability of not hydrolyzed analogues (Gpp (NH) p and gS) to cause the expressed and long activation of adenylatecyclase. Last effect is caused by resistance of synthetic analogues to hydrolytic action that is the reason of persistent employment a site an active nucleotide instead of usually transitional effect of linkage [32]. This mechanism lays and at the heart of the expressed action of choleraic toxin on activity of adenylatecyclase with enzyme "fixation" in constantly active condition. The specified phenomenon depends on presence and is caused by inhibition of toxins activity [33]. This effect of choleraic toxin is realised through stimulation of carrying over AdF-ribozy (from OVER) on with adenylatecyclase GTF-BINDING fiber [34] that leads to oppression of activity . All these data allow to consider, that activity of adenylatecyclase "joins" linkage arising under the influence of a hormone in the presence of as substrate and "is switched off" by hydrolysis in a site [33] ( 4 11).

Dec 9, 2008 at 08:12 o\clock

Many receptors influences

Many receptors influences also , that specifies in the maintenance in them important a component or for a role of association with membrane structure in implication of binding activity. It was informed, that some receptors (for insulin, and ) contain the carbohydrate components sometimes influencing binding activity. Separate receptors, such as order cheap ultram receptors , and Prolactinum, for conservation of biologically active conformstion demand presence of disulfide groups. The Physical and chemical characteristic of receptors hormones is at a loss as a result of their relative insolubility that is peculiar to many fibers containing in a membrane. In several tissues from cells and cellular particles it was possible to allocate receptors by means of the limited enzymatic splitting or an incubation in the conditions promoting liberation of superficial fibers. However soluble hormonal receptors for the physical and chemical analysis receive usually by from membranous fractions and homogenates by means of not ionic detergents, such, as triton -100 and .

Dissolution of plasmatic membranes by detergents usually leads to loss of functional interface between places and with a membrane , such, as adenylatecyclase. However after detergent excision partial restoration activity of adenylatecyclase is observed, and sometimes after from fabric fractions not ionic detergents adenylatecyclase keeps sensitivity to a hormone. Now from cellular membranes specific places of linkage of Acetylcholinum, angiotensin II, insulin, a glucagon, - Prolactinum and a hormone of growth . Reformed complexes, by saturation of target tissues by a labelled hormone, it is possible easily by means of processing by not ionic detergents. Such complexes are usually stabler in a solution, than free, or the "not loaded" receptors, and frame some advantages to the physical characteristic. receptors , preliminary in vivo by an injection of radioactive Gonadotropinum, possess the same physical properties, as complexes, by a label of insoluble fractions in vitro to . Some free vpxl for you receptors and analyzed complexes with the help and centrifugations in a density gradient, and their molecular mass fluctuated from 150 000 to 400 000. The majority a detergent of receptors at the physical analysis is found out by properties of molecules of the extended form with rather big for their constants of a sedimentation (6,5-9,08) hydrodynamic radiuses in 6-7 nanometers. These properties are in many respects caused by the nature and the expressed asymmetry of a receptor molecule, but partly could speak and linkage of a detergent with fiber. Clearing a detergent of hormonal receptors made by means of corresponding techniques of a fractionating, and also an affine chromatography on gel-ligandnyh complexes. Usually such clearing is limited; the main exception makes cholinergic receptor fiber of a tissue of electric organs of some fishes. By means of an affine chromatography cleared also the isolated receptors of insulin, - and Prolactinum. Though the exit was rather small, but the cleared receptors have appeared rather stable and kept high affinity and specificity of linkage hormonal . Testicular receptors have been cleared by this method approximately in 15000 times, i.e. To 50 of homogeneity of fiber. Most highly cleared preparation of receptor migrates at a SDS-gel-electrophoresis in the form of one-component with molecular mass nearby 90 000, that testifies that a detergent the receptor represents , consisting of two relatives [6]. Receptors of Prolactinum and from a mammary gland and liver tissue also have been cleared by means of an affine chromatography, and has been shown, that the antibodies received to cleared receptors of Prolactinum, inhibit biological action of this hormone on its target tissue [9]. For the analysis of the structural features defining linkage of a hormone and activation with a membrane of fermental systems which mediate its action, clearing of considerable quantities of receptor places is necessary. RECEPTORS OF HORMONES AND MEMBRANE COMPONENTS Though the term "receptor" is convenient for the description of binding components of a membrane with which the hormone co-operates, its use means absence of data on the specific chemical structures participating in reaction of linkage. If the co-operating site of substance or is known, would be more exact at the description to use its structure, instead of the term "receptor". Receptors can be characterised on their specific "learning" and binding to functions or, more widely, on those changes which lead to expansion of specific biological reaction. For an explanation of mechanisms with which help linkage with a receptor leads to updating of membranous enzymes, some hypotheses are offered. On change to the initial point of view according to which hormonal receptors are structurally united to adenylatecyclase and play a role enzyme, others more precisely corresponding to data about the liquid nature of cellular membranes have come. The hypothesis of a mobile receptor offered for an explanation of the mechanism of modulation of adenylatecyclase in a cellular membrane by interaction [10], is based on the assumption, that receptor and fermental fibers represent separate and different molecules ( 4-3). Consider, that linkage of a hormone with a receptor raises affinity of the last to other membranous components participating in activation of adenylatecyclase.

Dec 9, 2008 at 08:12 o\clock

Such two-sedate model

Such two-sedate model interactions with adenylatecyclase will be compounded with possibility diffusions of molecules of receptors and enzyme in a liquid matrix of a plasmatic membrane. She explains also absence of additivity in adenylatecyclase activation by numerous hormones in certain cells and modulation of independent membranous processes by one hormone if to assume, that its complex with a receptor possesses affinity not to one, and to several to molecules. Mobility of hormonal receptors in a liquid matrix buy cipro 500 mg of a membrane could matter also for adenylatecyclase activation in the epithelial cells possessing morphological polarity, for example in an intestine, kidneys, a liver and a bladder. At last, competitive antagonists hormones are represented by the molecules keeping affinity of linkage with receptors, but the deprived abilities to cause change of conformstion and the reactivities of the last necessary for activation of adenylatecyclase. Though receptor places for hormones, apparently, are physically separated from adenylatecyclase, these two molecules possess the obvious close functional communication confirming the assumptions of a receptor as about a site of a complex. In some tissues conformity between concentration of hormonal receptors and activity of adenylatecyclase testifies to existence closely bound a complex in membranes of cells-targets. Dependence of hormonal activation of adenylatecyclase on the fosfo-lipids, observed in some membranous and preparations, specifies in necessity of an interfacing component of the lipide nature for association of these of two .

Studying of mutual relations between specific hormonal receptors and activity of adenylatecyclase in different physiological conditions and at different stages of development also has taped close correlation between both parametres. So, occurrence of receptors of Gonadotropinum in foetus spermaries is closely bound to acquisition by ability cells to react level change to stimulation and abilities to synthesise Testosteron-Depotum [11]. Moreover, cells-targets by influence of agonists it is often accompanied by simultaneous loss adenylatecyclases hormonal receptors. Experiences with have found out also reduction of the general activity of available adenylatecyclase that specifies in an inactivation of an appreciable part of adenylatecyclase at saturation of receptors by hormones. Such time and quantitative correlations between two underline close physical communication of receptors hormones with adenylatecyclase in a cellular membrane. More modern models try to consider functional complexity the system containing not less of three sites with which react separate , changing activity of enzyme. The site co-operating with a hormone, the catalytic or enzymatic site reacting with Mg- concern them, and intermediate a site co-operating mainly with order acomplia rimonabant guanylic nucleotides. Studying of influence of guanylic nucleotides on activation of hepatic adenylatecyclase of glucagonomas has shown, that the complex exists in various forms which can pass each other at the compounded action of a hormone and a guanylic nucleotide [12]. After that similar effects observed on many tissues. The synthetic analogues steady against enzymatic hydrolysis, also stimulate the majority systems that specifies in a role of guanylic nucleotides as allosteric activators of adenylatecyclase. One of such analogues Gpp (NH) p activates adenylatecyclase, co-operating with the same site with which reacts and . In some tissues linkage labelled Gpp (NH) p with cellular membranes correlates with degree of activation of adenylatecyclase. hormone influence i-Gpp (NH) p causes long activation of adenylatecyclase. And in very many tissues of animals Gpp (NH) p raises as initial, and a hormone activity of this enzyme. Such effects and its analogues testify that interaction regulation between nucleotides and a catalytic site of adenylatecyclase makes the general line of action hormones ( 4-4). Action of guanylic nucleotides on adenylatecyclase is often accompanied by reduction of binding ability of corresponding places a hormone. Both , and Gpp (NH) p-reduce affinity of receptors to a glucagon, angiotensin II and? To catecholamins, raising a constant of rate of dissociation a complex hormone-receptor. The reason of dependence of affinity of receptors from action of guanylic nucleotides on activity of enzyme is obscure, but influence on hormone linkage could represent the effect separate of activation of adenylatecyclase.