[Estrogen receptors in the diagnosis and treatment of hormone-dependent tumors].

The paper presents the current data available on the etiology of tumor diseases, among other things, shows the role of hormones, namely: estrogens and their receptors, in the mechanism responsible for the occurrence of these diseases. Each tumor was shown to have its receptor status and to be unresponsive to this or that therapy differently. The efficiency of treatment and its prognosis may be determined if the receptor composition of an involved organ is estimated correctly.

[Physiological importance of numerous sex hormone receptors].

Numerous effects of sex hormones on the brain are mediated by interaction with intracellular steroid hormone receptors acting as regulators of transcription. These are the classical receptors ERalpha, ERbeta and ERgamma. Some estrogenic effects cannot be attributed to ERalpha or ERbeta, this suggests the existens of additional receptor subtypes.

[Receptor mechanisms of action of sex hormones. Can the receptor work without a ligand?].

Among endocrinologists, it is generally accepted that most of the effects of steroid hormones are transmitted to the cell through their receptors located on intracellular sites, mainly on the nuclei of cells, and these mechanisms are intensively studied. A lot of information has been accumulated about the specific function of each hormone, changes of which were observed after removal of the gland and its hormonal compensation. The basis of the position of endocrinologists in this situation is the fact that the removal of the gland eliminates many physiological and behavioral responses depending on the secretory function in this gland.

[Developmental stages of the Endocrinology Research Centre of the Russian Academy of Medical Sciences].

The article is devoted to the history of the development of the Endocrinology Research Centre.

[The influence of estrogens on the central nervous system].

The article is dedicated to the influence of sex hormones, especially estrogens, on the central nervous system. The author summarizes literature data and the results of his own research into the mechanism of estrogen action, both via cell receptors and neuromediator systems. The latter include cholinergic, catecholaminergic, and serotonergic systems of various brain structures, such as the hypothalamus, hippocamp, forebrain, substantia nigra etc.

Brain is an important source of GnRH in general circulation in the rat during prenatal and early postnatal ontogenesis.

This study was aimed to test our hypothesis that, in contrast to adult rats, in fetuses and neonates, a large amount of the brain-derived GnRH is delivered to the general circulation. The GnRH concentration and content were estimated in general circulation and in the forebrain in rats on the 18th embryonic day (E18), E21, 3rd postnatal day (P3) and P30-36. Moreover, the GnRH concentration was measured in general circulation on E21 following microsurgical lesion on E18 of the forebrain containing most GnRH neurons.

[Neuroendocrine effect of sex hormones].

The paper provides a generalization of data and the results of own experiments on influence ovarian steroids on the hypothalamus and other brain areas related to reproduction. Ovarian hormones have widespread effects throughout the brain: on catecholaminergic neurons and serotonergic pathways and the basal forebrain cholinergic system, as well as the hipocampus, spinal cord, nigrostriatal and mesolimbic system, in addition to glial cells and blood-brain barrier. The widespread influences of these various neuronal systems ovarian steroids have measurable effects on mood and affect as well as on cognition, with implications for dementia.

Influence of serotonin on the development and migration of gonadotropin-releasing hormone neurones in rat foetuses.

This study used a pharmacological approach to evaluate the consequences of the metabolic perturbations of neurotransmitters on brain development. Pregnant rats received p-chlorophenylalanine (pCPA), an inhibitor of serotonin (5-hydroxytryptamine, 5-HT) synthesis, or saline (control) from the 11th day of gestation once or daily up to the 15th, 17th and 20th day, followed by processing of the forebrain and/or nasal cranium of foetal males and females for high-performance liquid chromatography of monoamines, radioimmunoassay of gonadotropin-releasing hormone (GnRH) and quantitative and semiquantitative immunocytochemistry for GnRH. The pCPA treatment resulted in a 50-70% depletion of 5-HT in the nasal crania and forebrains at any studied age.

Role of sex hormones in development of pituitary adenoma.

Role of sex hormones in the development of pituitary adenomas was investigated by analyzing the content of nuclear estradiol and testosterone receptors in different tumors of the anterior pituitary: prolactinomas, meningiomas, growth hormone-producing adenomas, astrocytomas, neurinomas, and ependymomas. The concentration of nuclear estrogen and androgen receptors in prolactin-secreting pituitary adenomas was much higher than in growth hormone-producing adenomas and other pituitary tumors.

[The functional activity of the ATP-dependent K+ channels of normal pancreatic beta cells and in pathology].

The paper deals with the analysis of the status of ATP-dependent K+ channels of pancreatic beta cell functional by attenuated under the effect of streptozotocin and simultaneous assessment of their reaction to sulfonylamide agents glybenclamide, glipizil and glyclazid. Highly specific response of the tested ionic channels showed under the effect of both glucose and sulfonylurea agents. Analysis of the time course of electrophysiological processes coursing in them, showed appreciable changes in the time of the channel closing, which led to deceleration of insulin secretin starting from the moment of exposure to glucose or sulfonylurea agents till exocytosis of insulin quantum.

[Relationship between regulatory effects of serotonin and testosterone on the development of the LHRH producing system of the rat brain during the prenatal period of development].

We have performed radioimmunoassay of LHRH in rostral and septal-preoptic brain regions, as well as in mediobasal hypothalamus of male and female fetuses at day 21 of the prenatal period after the injection to pregnant females on days 11-20 of gestation of either p-chlorophenylalanine (PCPA) or of a combination of PCPA with ethane-1,2-dimethane sulfonate (EDS). Control animals received the injection of the same volume of physiological saline. In the control fetuses, both males and females, the level of LHRH in the rostral brain region was significantly lower than in the septal-preoptic region.

Neuroendocrine control of the gonadotropic function of the hypophysis in experimental diabetes.

The stability of the function of the reproductive system depends on a multitude of factors of the internal and external milieux. Serious disturbances in its function, with alterations in carbohydrate homeostasis, underlie such diseases as diabetes mellitus. Disturbances to the functional activity of the reproductive system in laboratory animals with diabetes are known to be associated not only with destructive changes in the gonads, but also with dysfunction of the hypothalamo-hypophyseal complex [9, 11].

[The neuroendocrine regulation of gonadotropin and prolactin secretion and the role of neuromediators].

The paper deals with the neuroendocrine relationships between true neuromediators of adrenergic and cholinergic nature as well as the neuromediators of peptidic character and the neurosecretory neurons controlling the secretion of gonadotropines and prolactine. The properties of about 30 neuromediators of different character with consideration for the structures of the central nervous system, participation in the synthesis and secretion of gonadoliberine, gonadotropines and prolactine and hence functioning of the reproductive system as a whole are characterized. The significance of the hormonal background of sexual steroids in the system of these complex relationships is analyzed.

[Characterization of pancreatic beta cell receptors binding sulfanilamide drugs].

Analysis of pancreatic beta-cell receptors binding the sulfanilamide drugs widely used in therapy of type II diabetes, such as glibenclamide, glipizide, and gliclazide, showed that these drugs are characterized by excellent parameters of specific binding to these receptors. The receptors were tested for two parameters: number of binding sites and dissociation constant. Glibenclamide was the most active of the drugs we tested, the other two agents being less active.

[Development of the reproductive system in the progeny of rats with streptozotocin diabetes].

Specificities of functioning and development of the reproductive system and mechanism of its regulation with hypothalamic structures were studied in the progeny of rats with streptozotocin diabetes. For this purpose pituitary sensitivity was analyzed in mature animals, as was functional capacity of the feedback system mediating the hypothalamic regulation of gonadotropin secretion in rat males and females at the age when this system normally starts functioning in health. The hypothalamo-hypophyseo-gonadal system feedback mechanism was found to develop in the progeny of female rats with streptozotocin diabetes later than in health.

[Analysis of hypothalamo-hypophyseal-gonadal interrelationships in female rats in experimentally induced diabetes].

Hypothalamo-hypophyseo-gonadal system functional activity was studied in rats with streptozotocin diabetes. In intact rats concentrations of sex hormones nuclear receptors were measured in the hypothalamic preoptic-anterior, mediobasal segments and in the adenohypophysis, as were blood serum gonadotropins and sex hormones. Estradiol and progesterone were injected to ovariectomized females and LH-RH levels measured in preoptic-anterior segment of the hypothalamus, arcuate nucleus, and median eminence, as well as LH and FSH concentrations in the blood in order to detect disorders in basal and cyclic gonadotropin secretion.

[Basal and luliberin-stimulated gonadotropin secretion in ovariectomized female rats with streptozotocin-induced diabetes].

In vitro insulin effect on basal and LH-RH-stimulated gonadotropin secretion in oophorectomized female rats with streptozotocin diabetes administered estradiol as replacing hormone therapy was studied. The results were compared to those obtained after a similar incubation of adenohypophyses of oophorectomized rats and of oophorectomized rats administered estradiol. Estradiol was found to change the type of LH-RH-stimulated gonadotropin secretion in oophorectomized animals.

Disturbance of neuroendocrine regulation of sexual behavior of male rats with streptozotocin diabetes.

Sexual behavior is a constituent of the reproductive function of the organism. In sexually mature individuals the synchronization of the level of sexual activity with the reaction of the hypothalamo-hypophyseo-gonadal system to the relevant environmental stimuli is a necessary condition for the preservation of the species. In this context, the study of the neuroendocrine mechanisms shaping a specific level of activity of sexual behavior is an important problem for investigators.