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Comparative studies on the functioning of the adrenal cortex in female rhesus macaques (Macaca mulatta) of different ages are reported – animals were aged 6–9 years (young adults; n = 5) and 20–26 years (old adults; n = 5). Corticosteroid concentrations (cortisol (F) and dehydroepiandrosterone sulfate (DHEAS)) were determined by specific radioimmunological and immunoenzyme methods in basal conditions, after acute stress (insulin–induced hypoglycemia, 2–h movement restriction), and after administration of dexamethasone. Basal F levels showed no marked age differences, while DHEAS concentrations in older animals decreased sharply. These animals also demonstrated weakened adrenal cortex responses to movement restriction, giving rise to delays in reaching peak F and DHEAS levels and decreases in the areas under their response curves (AUC) during the 4–h study period. In the dexamethasone test, the hypothalamo–hypophyseal–adrenal system of monkeys aged 20–26 years was relatively resistant to the suppressing effect of glucocorticoids via the negative feedback mechanism. It is suggested that disruption of feedback in the system controlling adrenal cortex function may be at least partially due to the development of peripheral blood steroid dysbalance with aging, this consisting particularly of a decrease in the DHEA (DHEAS) level; this steroid is known for its neurological activity.

Density of glass-forming Fe-B- and Co-B-based alloys in amorphous and crystalline states was studied in a temperature range of 20-900°C. The temperature dependences for the amorphous and crystalline samples were calculated from the results of dilatometry. The room-temperature density was determined by hydrostatic weighing. It was found that, after crystallization, the ribbons transform to a stable non-equilibrium crystalline state with density that is lower than that of the corresponding as-cast bulk alloys. Transition to the state with the equilibrium value of density is completed upon annealing at temperatures close to solidus temperatures.

In vivo experiments on adult Wistar rats, it has been found that intake of natural zeolites resulted in temporary decrease of renal water, sodium and potassium excretion. At the same time, reabsorption of water and electrolytes increased. This effect was due to the stimulation of Na+, K(+)-ATPase activity in thick ascending limb of Henle loop and hormonal changes: increase of insulin, thyroxin and aldosterone concentration in plasma. The water and ion content in most of the tissues under study was higher in the experimental group than in control. It has been suggested that renal response in rats with zeolites intake was compensatory lower as a result of gastrointestinal losses of ions and ion accumulation in tissues.

The authors studied humoral regulation state in vibration disease patients. Correlation analysis proved role of hormonal disturbances in pathogenesis of angiopathies and visceropathies characteristic for vibration disease.

Parameters of the cardiovascular system and the content of corticosterone, thyrotrophin, thyroxin, and triiodothyronine in the plasma, and norepinephrine in the myocardium were determined in male NISAG rats (hereditary stress-induced arterial hypertension) reared by normotensive Wistar rats. Cross-rearing of hypertensive rat pups by normotensive females attenuated arterial hypertension with a tendency to normalization of the examined parameters. This confirms the possibility of modifying hypertensive phenotype by changing the conditions of the early postnatal development.

Comparative studies on the functioning of the adrenal cortex in female rhesus macaques (Macaca mulatta) of different ages are reported - animals were aged 6-9 years (young adults; n = 5) and 20-26 years (old adults; n = 5). Corticosteroid concentrations (cortisol (F) and dehydroepiandrosterone sulfate (DHEAS)) were determined by specific radioimmunological and immunoenzyme methods in basal conditions, after acute stress (insulin-induced hypoglycemia, 2-h movement restriction), and after administration of dexamethasone. Basal F levels showed no marked age differences, while DHEAS concentrations in older animals decreased sharply. These animals also demonstrated weakened adrenal cortex responses to movement restriction, giving rise to delays in reaching peak F and DHEAS levels and decreases in the areas under their response curves (AUC) during the 4-h study period. In the dexamethasone test, the hypothalamo-hypophyseal-adrenal system of monkeys aged 20-26 years was relatively resistant to the suppressing effect of glucocorticoids via the negative feedback mechanism. It is suggested that disruption of feedback in the system controlling adrenal cortex function may be at least partially due to the development of peripheral blood steroid dysbalance with aging, this consisting particularly of a decrease in the DHEA (DHEAS) level; this steroid is known for its neurological activity.

1. The promising nature of the proposed method of predicting the vibration levels in structures and the ground, which is based on experimental data on the harmonic oscillations of a small footing, is demonstrated. 2. One of the essential stages of the method is to determine curves of the dynamic contact stresses acting over the lower surface of the foundation under design. It is established that the latter are in different phases with respect to one another and lead the displacement of the foundation, and also that at no time do the dynamic contact stresses equal zero over the entire lower surface of the foundation. 3. The method makes it possible to compute the elastic and damping characteristics of the beds of foundations, which differ in shape and area of the lower surface, to determine the vibration level of structures interacting with the ground, and to determine the level of ground vibrations beyond the structure both on the surface, and within the ground, as well as in surrounding structures. Experiments with a small-foundation footing are much cheaper than experiments with certain foundations that are similar in any respect to a prototype foundation, particularly where the latter has large dimensions. 4. It is necessary to conduct studies in the proposed direction mainly to accumulate experimental data.

Adrenal and testicular function of sexually immature and adult male baboons (Papiohamadryas) was investigated during immobilization stress. The concentrations of testosterone, 5α-dihydrotestosterone, hydrocortisone, and intermediate products of their biosynthesis — progesterone, pregnenolone, 17-hydroxyprogesterone, 17-hydroxypregnenolone, and 11-deoxycortisol — in the peripheral blood plasma of the monkeys were determined by a radioimmunological method. The main age differences in the character of the hormonal response to stress were shown to be the absence of changes in the blood androgen concentration of the immature animals and the smaller increase in the hydrocortisone concentration in them than in the adult monkeys. The concentrations of precursors of the steroid hormones fell considerably in the immature monkeys during stress, whereas in the adult animals their level rose 3–4-fold.

The character of changes in the level of 12 steroids in peripheral blood plasma of male baboons (Papio hamadryas) under conditions of immobilization and surgical stress was determined by a radioimmunological method. During stress the concentration of androgens in the blood plasma of the monkeys is reduced, whereas the concentration of precursors of the steroid hormones and of hydrocortisone is increased. These changes are opposite in phase to the diurnal rhythm of the steroids. The fall in the levels of testosterone and dihydrotestosterone and the rise in the concentrations of pregnenolone, 17 α-hydroxypregnenolone, and 17 α-hydroxyprogesterone in the blood plasma of male baboons exposed to stress were found to be the most objective and sensitive criteria of the stressor situation.

This paper describes a study of possible dependence of the androgen level in male baboons on the time of year. Plasma was obtained by centrifugation of the blood at 3000 rpm and the following androgens were determined by radioimmunoassay, using chromatographic separation of the steroids on columns with celite: testosterone, 5s-dihydrotestosterone, and dehydroepiandrosterone. Plasma steriod concentrations were calculated and the results were subjected to statistical analysis by Students test. Seasonal change in the concentration of steroids in the animals' blood plasma were discovered. The results of androgen assay throughout the year and determination of their mean annual concentrations are shown.

Radioimmunoassay was used to investigate circadian rhythms of blood plasma testosterone, 5 alpha-dihydrotestosterone, androstendione and dehydroepiandrosterone in intact animals and in those preadapted for experimental conditions. Blood plasma of monkey demonstrated monophasic circadian rhythms in the levels of androstendione, dehydroepiandrosterone and 5 alpha-dihydrotestosterone, with the maximal values seen early in the morning and minimal values in the evening. Circadian rhythms of testosterone were opposite in character. The adaptation of monkeys for housing and experimental conditions was marked by an increase in testosterone and 5 alpha-dihydrotestosterone levels in the blood as well as by an insignificant elevation of the levels of androgens of adrenal origin, leading to the changes in circadian rhythms of steroid hormones.

Adult baboons (5 males and 5 females) were exposed to immobilization stress by being strapped to a table in a horizontal position for 2 h. In females the experiment was performed during both the follicular and luteal phase. Peripheral blood was withdrawn at frequent intervals, the first sample just before immobilization, and the last one 3 days later. A number of steroids were measured in blood plasma samples by radioimmunoassay (17-hydroxypregnenolone, 17-hydroxyprogesterone, pregnenolone, testosterone, dihydrotestosterone, progesterone, 20α-dihydroprogesterone, oestrone, oestradiol) or competitive protein binding (cortisol) techniques. The cortisol levels exhibited a marked increase in both sexes. This increase was observed already during the immobilization and lasted for approximately 24 h. A similar, even more pronounced increase was seen in 17-hydroxypregnenolone, 17-hydroxyprogesterone and pregnenolone levels. A marked, long-lasting (72 h) decrease of testosterone and dihydrotestosterone levels was a consistent finding in male baboons. This was not observed in the females which, on the other hand, exhibited a marked decrease (duration 48 h) of progesterone and 20α-dihydroprogesterone levels during the luteal phase, and a significant decrease (duration > 24 h) of oestradiol and oestrone concentrations during the follicular phase. It is concluded that stress has a marked inhibitory action on gonadal function both in male and female baboons. In females the inhibition of steroidogenetic function is exerted both on the ovarian follicles and on the corpus luteum.

The levels of hydrocortisone, 11-deoxycortisole, 17-hydroxypregnenolone, 17-hydroxyprogesterone, 20-dihydroprogesterone, pregnenolone and progesterone were measured in blood plasma of adult male hamadryas baboons within a year using radioimmunoassay. Seasonal fluctuations characterized by the highest content of corticosteroids in spring-summer period and a considerable decrease of their concentration in autumn months have been revealed.

Annual blood plasma levels of testosterone, 5 alpha-dehydrotestosterone and dehydroepiandrosterone were measured in hamadryas baboon males using radioimmunoassay. Fluctuations characterized by a decrease in testosterone and 5 alpha-dehydrotestosterone concentrations in spring and an increase in their levels in autumn have been established. Dehydroepiandrosterone level was characterized by two minimal points--at the beginning of the year and in August. The following average annual levels of androgens have been determined: 22.5 nmol/l for testosterone; 4.7 nmol/l for 5 alpha-dehydrotestosterone; 19.0 nmol/l for hydroepiandrosterone.

The correlation between hormonal activity of hypophysis-gonad system and hierarchical status of hamadryas baboon males in an isolated group was studied. It has been established that the level of testosterone was higher in males occupying the leading position in a separate subgroup. A high level of sexual hormone was observed in animals with greater muscular mass and age. No correlation between hierarchical status and luteinizing hormone blood content has been observed in baboon males.

Function of the adrenals and testes in immature and adult male baboons was studied in immobilization stress conditions. Concentrations of testosterone, 5d-dihydrotestosterone, hydrocortisone and precursors (progesterone, pregnenolone, 17-hydroxyprogesterone, 17-hydroxypregnenolone and 11-deoxycortisol) were determined in peripheral blood plasma by radioimmunoassay. It was shown that the main age-specific differences in hormonal reaction to stress are an unchanged level of androgens in the blood of immature animals and less marked increase in the level of hydrocortisone as compared to adult monkeys. The content of steroid precursors in the blood of immature monkeys diminished significantly in stressful conditions while in adult monkeys the level of the precursors was 3-5 times as increased.

A hypophysis-ovarian system of barren cows was shown to be highly sensitive to the effect of the preparation RL-S. The preparation possessing a simple chemical structure, proved to regulate the functional activity of endocrine glands. After treatment with the preparation RL-S concentration of estradiol was increased 1.81-fold in blood plasma of cows studied as compared with controls, while content of luteinizing hormone was elevated by 12.3%. In the groups of experimental animals the sexual cycle was normalized as content of progesterone was increased in blood with simultaneous decrease in estradiol concentration.

The occurrence of a single-phase circadian rhythm in the content of cortisole, 11-deoxycortisole, 17-hydroxypregnenolone, 17-hydroxyprogesterone, pregnenolone and progesterone in the blood plasma of hamadryas baboons was established by radioimmunoassay with peak levels early in the morning and minimum ones in the evening. The time course of changes in aldosterone levels in the intact animals significantly differs from that in the adapted ones. The maintenance of animals under other ecological conditions results in the decreased levels of all steroids studied and in significant changes in circadian rhythms of the content of cortisol precursors.

Hierarchic status-dependent hormonal activity of pituitary-gonadal system was studied in an isolated group of hamadryas baboons. Testosterone level was higher in dominating males. The level of sex hormone was higher in aged animals with great muscle mass. No correlation was observed between hierarchic status of hamadryas baboon males and the blood level of luteinizing hormone.