[Hypercorticism during streptozotocin diabetes and mifepristone administration: the role of cyclic adenosine monophosphate]. / Giperkortitsizm pri streptozototsinovom diabete i vvedenii mifepristona: rol' tsiklicheskogo adenozinmonofosfata.

It was studed basal and ACTH-stimulated production of cyclic adenosine monophosphate (cAMP) and corticosteroid hormones (progesterone and corticosterone) in rat adrenals in vitro under streptozotocin diabetes, in conditions of mifepristone administration and their combination. It was shown that in streptozotocin diabetes animals, both the basal and adrenocorticotropic hormone (ACTH) stimulated cAMP production significantly increased; this was accompanied by the increase in basal and ACTH-stimulated progesterone and corticosterone production in rat adrenals in vitro. Repeated administration of mifepristone to control and diabetic rats caused an increase mainly in ACTH-stimulated production of the main glucocorticoid hormone, corticosterone, without additional changes in the cAMP level. The results obtained suggest activation of two mechanisms of steroidogenesis enhancement in experimental animals. In rats with streptozotocin diabetes, both basal and ACTH-stimulated activity of all stages of steroidogenesis increase, which is mediated by the increased formation of cAMP as second messenger mediating the ACTH action on adrenocortical cells. Prolonged administration of mifepristone to control and diabetic rats resulted in increased activity of only late stages of steroidogenesis with predominant elevation of synthesis of physiologically active hormone corticosterone without additional changes in cAMP production level.

Effects Mifepristone on Aminotransferase Activities in the Liver in Rats with Streptozotocin-Induced Diabetes Mellitus.

The glucocorticoid status and activities of ALT, AST, and tyrosine aminotransferase in the liver are studied in rats with streptozotocin-induced diabetes mellitus in response to repeated intraperitoneal injections of mifepristone. Diabetic rats develop an increase of the blood corticosterone and liver aminotransferase levels in response to mifepristone. These results indicate that in diabetic animals the glucocorticoid hormones with high blood concentrations, increasing still more in response to mifepristone, overcome the receptor blockade, and realize their regulatory functions in hepatocytes. The effects of mifepristone on ALT activity are the most manifest. In normal rats, only ALT activity is increasing in response to mifepristone, while in rats with streptozotocin-induced diabetes mellitus, ALT activity increases more intensely than activities of tyrosine aminotransferase and AST.

Synchronization of the Estrous Cycle against the Background of Increased Excitability in Rats Selected for Catatonic Type of Reaction.

Selection for the elevation of catatonic type of reaction in female GC rats ("genetic" and "catatonia") was followed by an increase in the number of intense running episodes in response to acoustic stimulation. The observed changes are typical of increased general excitability in these animals. The phenomenon of estrous cycle synchronization was confirmed by variations in the concentrations of estradiol and progesterone in groups of Wistar and GC rats differing by the degree of synchronization. Some differences were found in the concentration of main sex hormones in the blood from female GC and Wistar rats.

[EEG alpha indices in dependence on the menstrual cycle phase and salivary progesterone].

The effects of the neurohumoral status on the EEG alpha - activity indices were studied in a within-subject design with 78 women aged 18-27 years during 1-2 menstrual cycle. Psychometric and EEG indices of alpha waves basal body temperature, saliva progesterone and cortisol level were monitored every 2-3 days. Menstrual and follicular recording sessions occurred before the ovulatory temperature rise, luteal recording session--after increasing progesterone level more than 20% respect to previous day and premenstrual sessions after decreasing progesterone level more that 20% respect to previous day. The design consisted of rest and task periods EEG, EMG and ECG recordings. Half the subjects began during their menstrual phase and half began during their luteal phase. All 5 phases were compared for differences between psychometric features EEG alpha activity, EMG and ECG baseline resting levels, as well as for reactivity to cognitive task. The results showed menstrual phase differences in all psychometric and alpha EEG indices. The cognitive fluency, alpha peak frequency, alpha band width, power in alpha-2 frequency range are maximal at luteal, alpha visual activation and reactivity to cognitive task performance--at follicular phase. The hypothesis that the EEG alpha activity depends on the hormonal status supported by the positive association salivary progesterone level with the alpha peak frequency, power in the alpha-2 band and negative--with the power of the alpha-1 band. According these results, we conclude that psycho-physiological recording sessions with women might be provided with a glance to phase of menstrual cycle.

[The response of EEG activation in different neurohumoral conditions].

In order to examine under what neurohumoral condition response to the usual opening of the eyes is an incentive for the activation, electroencephalographic, electrocardiographic and electromyographic characteristics of the eyes open reaction in relation to the psychometric indicators of emotional stress and cognitive performance were recorded in 59 healthy women aged 18-27 every 2-3 days for 1-2 menstrual cycles, established in accordance with the morning levels of progesterone. For excluding NOVELTY factor influence one 29 women started monitoring at menstrual phase and other 30--at luteal phase of menstrual cycle. 30 women participated in a one-time monitoring, in which the relationship of these parameters with the current level of progesterone and cortisol in saliva was studied. Two factors ANOVA showed that the depth of the power suppression and the width of the individually determined low frequency alpha EEG range on follicular is more than on the luteal phase of the menstrual cycle of women and are influenced the NOVELTY. "Berger effect" indices of the upper alpha range are not changed depending on the neurohumoral status. Depth of the amplitude decrease and width of merely low-frequency alpha band could predict the activation in the eyes open response due to unidirectional changes and relationship to vegetative and hormonal characteristics of the activation. It was firstly established that eyes opening is an incentive factor to the activaition only when neurohumoral state corresponds to the follicular phase of the women mensrual cycle. This study reviles the dependence of the neuronal and vegetative activation mechanisms of the individual alpha frequency profile EEG and neurohumoral status.

[Serum hormonal levels in diamond-extracting industry workers of Yakutia, with surface and underground type of work].

The authors studied influence of work type (surface or underground) on serum hormonal levels in male workers of "International" mine within diamond-extracting complex of Yakutia-Sakha Republic. The results obtained show compensation and adaptation changes of endocrine system in males engaged into underground work vs. those of surface work.

[Iodine availability, thyroid structure and function in residents of the city of Mirny, Republic of Sakha (Yakutia)].

Iodine availability for residents of the city of Mirny, Republic of Sakha (Yakutia), was estimated from urinary iodine and creatinine levels and their calculated ratio. Median of iodine/creatinine ratio in the groups of children and adults included in the study was 167.2 and 110.5 mcg/g respectively. Goiter was diagnosed by ultrasound in 0.4% of men and 4.9% of women. Diffuse and focal changes of the thyroid echographic pattern were revealed in the overwhelming majority of the examined subjects (91.7% of the adults and 66.1% of the children). The frequency of thyroid nodules was 5.0% and 20.3% in men and women respectively. Serum TSH level exceeded the respective reference values in 10.9% of the men and 18.2% of the women.

Development of insulin resistance in experimental animals during long-term glucocorticoid treatment.

Long-term treatment with glucocorticoids led to the development of insulin resistance in experimental animals, which was confirmed by a progressive increase in blood insulin level and decrease in the glucose/insulin index. The comparative study showed that hydrocortisone produced more pronounced and rapid changes than dexamethasone. However, we found no differences in the glucose/insulin index by the 23rd day of treatment with these hormones.