[Adrenal cortical steroidogenesis and adrenal androgen secretion in Cushing disease].

The daily time course of changes In the secretion of dehydroepiandrosterone, its sulfate, and Cortisol, as well as their precursors (17-α-hydroxypregnenolone, 17-α-hydroxyprogesterone, and 11-deoxycortisol) was studied in patients with Itsenko-Cushing syndrome and disease. The mean daily blood concentrations were calculated for each hormone. The activity of the enzymatic systems of steroidogenesis was estimated from the ratio of the mean daily concentrations of the precursor of an enzymatic reaction to those of its product. The findings suggest that production of elevated concentrations of corticosteroids (both Cortisol and androgens) through the Δ5-pathway with the enhanced activity of 11ß-hydroxylase and sulfatase is characteristic of patients with Itsenko-Cushing disease. In patients with Itsenko-Cushing syndrome, the generation of higher Cortisol levels is accomplished through the Δ4-pathway whereas the synthesis of androgens through the Δ5-pathway is minimal due to the decreased activity of 17,20-desmolase.

[Comparative analysis of the determination of serum testosterobe levels by different methods].

The serum concentration of total testosterone were measured in 100 male patients aged 19-65 years who had visited the clinic and polyclinic of the Endocrinology Research Center, Russian Academy of Medical Sciences for complaints about different dysfunctions of the endocrine glands. Testosterone was measured by the well-known currently available technologies: automatic Vitros ECi, Architect, and Access multianalyzers, manual Delfia and DRS enzyme immunoassay kits, and radioimmunoassay (RIA) that had been developed within the framework of the WHO Human Reproduction Programme and adjusted by the reference assay (gas chromatography/mass spectroscopy). The closest results were obtained when determining the level of testosterone by RIA and by means of the Vitros ECi multianalyzer (13.1 vs 13.0 nmol/l, medians). All other technologies demonstrated a low correlation with RIS and had positive biases, especially with the use of the Delfia kits (as high as 60 and, at low concentrations, 100%). The positive bias tends to decrease in patients with higher testosterone levels ( > 10 nmol/l) for all studied methods.

Endocrine and reproductive health status of men who had experienced short-term radiation exposure at Chernobyl.

Hormonal and semen parameters in 416 men aged 25-45 years were examined: 328 were men who cleaned the territory around the Chernobyl nuclear reactor (called 'liquidators') and 88 were healthy age-matched controls. The dose of radiation received by the liquidators was 0.16 +/- 0.08 Gy. LH, FSH, prolactin, testosterone and cortisol levels were assayed using WHO-matched reagents. Semen analyses were performed according to the WHO Manual (1992). The mean concentration of all hormones in liquidators and controls were within the WHO-defined normal range. The mean levels of LH and cortisol in liquidators were significantly lower (p = 0.013 and p < 0.001, respectively) and testosterone significantly higher (p = 0.023) than in controls. The variations in hormone levels in liquidators were not correlated with the acquired doses of radiation as measured by personal dosimeters (film badges). Semen parameters in a subgroup of 70 liquidators were within the normal WHO-defined range. The percentage of normal forms of spermatozoa in liquidators (35.0 +/- 13.1%) was significantly lower (p < 0.015) than in a control group (42.8 +/- 8.9%). The study has shown that exposure of men to relatively short-term radiation did not cause long-lasting disruption of their endocrine status and spermatogenesis. The study was 7-9 years retrospective and it is therefore impossible to infer what the immediate effects of the radiation exposure were on these parameters.

[Effect of corticoliberin and naloxone on the functional activity of the hypophyseal-gonadal system in monkeys]. / Vliianie kortikoliberina i naloksona na funktsional'nuiu aktivnost' sistemy gipofiz-gonady u obez'ian.

Experiments were staged on male Papio hamadryas for a study of CRF and naloxone action on the time course of LH and testosterone in peripheral blood. LH was determined by a biological micromethod in vitro; ACTH, cortisol and testosterone were determined by radioimmunoassays. Exogenous CRF was shown to increase inhibitory action of acute "procedure" stress (frequent fixation of monkeys and venipuncture for taking blood samples) of the secretion of LH but not testosterone. Opioid preceptor blockade with naloxone prevented the appearance of inhibitory action of stress and CRF on hypophyseal gonadotropic function rather than on testicular secretory activity. The time course of LH and testosterone after naloxone administration of naloxone combined with CRF has shown that inhibition of testosterone secretion in stress does not depend on a response of gonadotropins and is determined by other (additional) factors.

[The role of ACTH in regulating dehydroepiandrosterone secretion in primates]. / Rol' AKTG v reguliatsii sekretsii degidroépiandrosterona u primatov.

The effect of repeated administration of a prolonged ACTH agent on the secretion of glucocorticoids, dehydroepiandrosterone (DEA) and delta 4- and delta 5-precursors was studied in experiments on male hamadryas baboons. The administration of Sinacten-depot at a dose of 1 mg for 5 days caused a noticeable decrease in the basal levels of cortisol, 11-deoxycortisol, pregnenolone, 17-oxypregnenolone, and DEA. Response of the adrenal glands to additional ACTH stimulation against a background of lowered basal indicators was completely preserved and increased 2-3-fold for pregnenolone, 17-oxypregnenolone and DEA. The amplitude of a maximum increment of cortisol in response to stress before and after ACTH treatment did not differ significantly, and for DEA it increased three times. Immobilization stress after preliminary ACTH treatment caused a stable increase in the level of DEA during stress factor action as well as 3 days after drug action.

[Effect of immobilization stress on the gonadotropic function of the hypophysis in male hamadryas baboons (Papio hamadryas)]. / Vliianie immobilizatsionnogo stressa na gonadotropnuiu funktsiiu gipofiza samtsov pavianov gamadrilov (Papio hamdryas).

The plasma levels of luteinizing hormone (LH) and testosterone were studied in intact and castrated male baboons exposed to 2- and 10-hour periods of immobilization. Presented data have shown that immobilization stress induced a marked decrease in LH concentration both in intact and castrated monkeys. Changes in LH concentration positively correlated with plasma levels of testosterone only during the experimental procedures. During three days after immobilization there was a sharp dissociation in the dynamics of testosterone levels remained low and LH returned to normal values. We can suggest that it is not absolute LH level that is responsible for the changes in testosterone secretion during the immobilization stress.

[Effect of luliberin on the secretion of luteinizing hormone as a function of the phase of menstrual cycle in intact and castrated female Papio hamadryas]. / Vliianie liuliberina na sekretsiiu liuteiniziruiushchego gormona v zavisimosti ot fazy menstrual'nogo tsikla u intaktnykh i kastrirovannykh samok pavianov gamadrilov.

A comparative study of the LH time course in response to the administration of a standard dose of LH/RF was conducted in intact and castrated female papio hamadryas to find out the relationship between hypophyseal sensitivity to LH/RF action and the level of sex steroid hormones in the peripheral blood. A bioradioimmunoassay adapted for the monkey plasma was employed to measure the level of biologically active LH in the peripheral blood plasma. A stimulating effect of LH/RF on the hypophyseal LH secretion both in intact animals in different phases of the menstrual cycle and in gonadectomized females was established. The relationship between the nature of the LH time course and the level of sex steroid hormones in the peripheral blood plasma was shown; a prolonged high level of LH reciprocal secretion into the follicular phase occurred against a background of a high and constant estradiol/progesterone ratio, and LH one-type impulse release into the luteal phase and in castrated females occurred against a background of a low value of the ratio of these hormones.

[Effect of ACTH on the corticosteroid and progesterone levels in female hamadryas baboons in relation to the menstrual cycle phase]. / Vliianie AKTG na uroven' kortikosteroidov i progesterona u samok pavianov gamadrilov v zavisimosti ot fazy menstrual'nogo tsikla.

The effect of exogenous ACTH on the endogenous function of the steroid-producing glands has been investigated in hamadryas baboon females depending on the level of sex hormones in the body. The content of corticosteroids and progesterone in peripheral blood plasma was measured by radioimmunoassay. It has been established that the time course of changes in the adrenal gland response to administration of a standard ACTH dose was of the same type in the different menstrual cycle phases. The inhibitory effect of ACTH on progesterone secretion in ovarian corpus luteum being active has been revealed.

[Effect of gonadectomy and luliberin on the gonadotropic function of the hypophysis in Papio hamadryas]. / Vliianie gonadektomii i liuliberina na gonadotropnuiu funktsiiu gipofiza u pavianov gamadrilov (Papio hamadryas).

A comparative study was made of the effect of LH-RH on the hypophyseal reactivity in intact and castrated male papio hamadryas. Hypophysis gonadotropic function was evaluated by the content of the biologically active luteinizing hormone in the peripheral blood plasma which was determined by an in-vitro biological method. Bilateral gonadectomy caused an increase in the luteinizing hormone concentration by an average of 600% in this species of apes. The hormone level got stable at maximum values in the course of 3 days. After administration of exogenous LH-RH the maximum LH concentration both in intact and castrated animals was recorded 30 min after the administration of a hypothalamic mediator. Basal and LH-RH stimulated values of the LH concentration were higher in castrated apes. However the period of a hormone concentration increase in the peripheral blood of intact animals exceeds the response time in castrated males. The authors discuss possible mechanisms of change in the hypophyseal reactivity to LH-RH under conditions of surgical disconnection of testicle function.

[Effect of human chorionic gonadotropin on the endocrine function of Papio testes]. / Vliianie khorionicheskogo gonadotropina cheloveka na éndokrinnuiu funktsiiu semennikov pavianov gamadrilov.

Radioimmunoassay was used to study secretion of Papio hamadryas testis under stimulation with human chorionic gonadotropin (hCG). It was discovered that hCG had an acute stimulating effect on testicular secretion of testosterone, androstendione and 17-hydroxyprogesterone. It was demonstrated that repeated stimulation with hCG in the presence of the maximal secretory response of the testis (24 h after the first injection and in the presence of its partial reduction (after 72 h) did not provoke any additional rise of testosterone secretion. Unlike the initial response, repeated stimulation with hCG gave rise to dissociation in the time-course of testosterone and 17-hydroxyprogesterone responses. The data obtained attest to temporary "desensitization" of the testis to repeated stimulation with hCG.

[Steroid metabolism in primates. XX. Excretion of C21-steroids in urine of women and baboons (Papio hamadryas) during pregnancy]. / Steroidstoffwechsel bei Primaten. XX. Ausscheidung von C21-Steroiden im Urin bei Frauen und beim Pavian (Papio hamadryas) während der Schwangershaft.

Urinary excretion of 10 C21 steroids was investigated in women and baboons (Papio hamadryas) in various stages of pregnancy, in comparison to controls. In pregnant women, excretion of total C21 steroids is slightly increased, whereas in pregnant baboons it is slightly decreased. In women, excretion of tetrahydrocortisol and tetrahydrocortisone is diminished, that of 20 beta-OH-F (11-beta,17alpha,20beta,21-tetrahydroxy-4-pregnen-3,20-dione) and of 11-deoxycortisol is increased. In pregnant baboons no significant alterations in corticosteroid metabolism were established.