[Morphofunctional state of reproductive system of ageing male rats in case of using nanocerium].

The influence of nanocrystalline cerium dioxide (NCD, 1 and 100 mg/kg per os daily for 10 days) on morphofuctional state of reproductive system was investigated in ageing male rats. It has been established that activation of hormone-producing testicular Leydig's cells, as well as of secretory and proliferative processes in prostate, underlies the stimulating effect of NCD at a dose 1 mg/kg on hormonal function of testis and spermatogenesis of ageing male rats. NCD used at a dose 100 mg/kg had no significant effect on the assessed indices of morphofuctional state of reproductive system.

[The dynamics of hormonal changes in female rats exposed to chronic stress and androgen excess during pubescence].

The dynamics of blood plasma corticosterone, testosterone and androstenedione levels and their reaction to acute stress (30 min immobilization) in 35-, 40- and 45-day old female rats exposed to chronic stress (daily 30-min immobilization from 35th to 45th day of life) and/or to excess of exogenous androgens (implantation of capsules with testosterone to 33-day old animals) during pubescence was studied. Both control and experimental females in all age groups responded to acute stress by significant elevation of blood plasma corticosterone levels. At the end of the chronic stress session, the extent of adrenals activation in response to acute dosed stress was lowered in androgenized 45-day old females and increased gradually in stressed ones. After acute stress, the blood plasma testosterone level decreased in control 35-day old females and rose - in androgenized females against 10-fold rising of basal hormonal level. In 40-day old control females as well as in androgenized ones exposed to chronic stress during 5 days, the acute dosed stress did not result in significant changes of blood plasma testosterone and elevated blood plasma androstenedione. Stressed 40-day old females with increased basal androstenedione secretion did not respond to acute stress by the hormone level changes while blood plasma testosterone declined significantly. At the end ofpubescence (on the 45th day of life), acute stress did not affect the blood plasma testosterone level in control and androgenized animals, while decreased it in stressed females and increased - in androgenized rats exposed to chronic stress against elevated basal level of the hormone. The conclusion is made about possible functional relationship between the changes in hormonal homeostasis during pubescence and development of reproductive system in mature animals.

[Effects of cytokine-like polypeptide EMAP II and flutamide on the testosterone-stimulated prostate of castrated rats].

The effects of separate and combined administration of cytokine-like polypeptide EMAP II and flutamide, a nonsteroid antiandrogen, on morphology and function of the accessory sexual glands in castrated rats stimulated with testosterone propionate were studied. We found antiangiogenic, procoagulating and proapoptotic effects of EMAP II in the ventral prostate. Combined administration of the preparations enhanced their antiprostatic effects, which were manifested in inhibition of the androgen-dependent processes in prostate tissues, changes in proliferation and apoptosis, DNA, RNA and protein contents. We conclude that combined administration of EMAP II and flutamide can be used for development of new therapeutic modalities in prostate cancer.

[Effect of chronic stress during puberty on the reproductive system of female rats with experimental hyperandrogenicity].

Effects of chronic stress (daily 30-min immobilization) on 35-45 days of life and its combination with androgenization (implantation of testosterone-containing capsules on 33rd day of life) on reproductive system of 2.5 month old female rats were studied. The term of sexual maturation, estrous cycles regularity and structure, blood plasma levels of testosterone, progesterone and androstenedione as well as ovarian histology were examined. Androgenization resulted in the blood plasma testosterone level increase and the androstenedione level decrease, development of oligo- or anovulatory condition characterized by disorders or discontinuation in estrous cyclicity. We also detected abrupt reduction or absence of postovulatory luteal bodies, cysts formation and ovarian interstitial tissue overgrowth. All experimental animals had normal blood plasma corticosterone level. Stressed rats had no considerable changes in reproductive system except of some cyclicity disorders. Stressed against androgenization rats demonstrated delayed pubescence, an increased number of ovarian cysts along with attenuation ofandrogenization-caused negative effects on the sexual cyclicity.

[Enhancing effect of androgen receptor antagonist on gonadotropic inductors of ovulation in rats with polycystic ovaries].

Hormonal indices, phase pattern of estrous cycles, and histological structure of the ovaries were studied in female rats with polycystic ovaries caused by subcutaneous implantation of Silastic capsules with testosterone after consecutive treatment with non-steroid antiandrogen, flutamide (flutafarm), urinary FSH (menopur) and HCG (choragon). It was shown that while the plasma testosterone level was increased, administration of the drugs in subtherapeutical doses interrupted persistent diestrus, renewed estrous cycle, gonadal and uterine weights, induced appearance of postovulatory luteal bodies and restored fertility. Therefore, antiandrogen potentiation of pharmnnaco-dynamic effect of the gonadotropins with regard to their ability to ovulation induction was found out.

[Calcium-dependent mechanisms of stress disorders and noradrenergic responses of the hypothalamo-pituitary-adrenal system in neonatally androgenized female rats].

The effects of neonatal administration ofverapamil, a calcium L-type channel blocker, on the stress and noradrenergic responses of hypothalamo-pituitary-adrenal (HPA) axis in adult female rats with anovulatory syndrome induced by neonatal androgenization have been studied. There was no adrenocortical response to an acute stress nor noradrenaline infusion in the 3rd brain ventricle in females with persistent estrus. Verapamil pretreatment completely restored the adrenocortical responses to normal level. No changes were found in studied parameters following treatment with verapamil alone. These results demonstrate possible involvement of calcium signalling in pathogenesis of the disorders of HPA function in adult female rats, induced by neonatal androgenization.

[The role of the ovarian steroid aromatase in pathogenesis of reproductive cycles disorders].

In the rats with regular estrous cycles effects of letrozole, a steroid aromatase inhibitor, on the enzyme activity in ovarian tissues and reproductive system condition were studied. Letrozole was administered per os daily in a dose of 1 mg/kg b.w. over 10 days. As the result of treatment, 20.5-fold decrease in aromatase activity was obtained. All animals have developed persistent anestrus with vaginal smear patterns being similar to diestrus. Uterine weights were two-fold less than that of controls, and ovarian weights increased by one third. The ovaries contained multiple cystoidal follicles. Results of the study demonstrate the key role of ovarian steroid aromatase in letrozole-induced disorders of reproductive cycles. Letrozole might be recommended for experimental modeling of reproductive cycle disorders in female rats.

[Effect of combined application of the synthetic luteinizing hormone-releasing hormone agonist and nonsteroidal antiandrogen on the reproductive system of male rats].

The influence of combined use of different doses of LGRH agonist (Surfagon) and non-steroidal antiandrogen Flutamide (Niftolid) on the structure and functional state of accessory sexual glands and hypophyseal-gonadal system of rate males had been studied. Optimal ratio of the drug doses for achieving the best antiprostatic effect has been determined. It was shown that combined use of above mentioned drugs resulted in the potentiation of antiprostatic effects. A maximal effect was observed after 30 days of Surfagon administration in a dose of 50 mg/kg b.w. together with flutamid in a dose of 10 mg/kg. b.w. Such a combination of drugs is recommended for clinical approbation as therapy for prostate cancer.

[The hypothalamic-hypophyseal-gonadal system and its functional reserve during long-term vibration and noise]. / Stan systemy hipotalamus-hipofiz-honady ta ïï funktsional'nykh rezerviv pry tryvalii diï vibratsiï i shumu.

Male rats were exposed to influence of vibration and noise in a drown chamber for 4 hours 5 times a week during 4 months. The corrected velocity of vibration was 4.58 x 10(-2) m/s. Steady broadland noise with the level of sound of 92 dBA covered the standardized range of frequencies, starting with 63 Gc. The noise caused earlier and more expressed changes in functional gonadotropic reserves of the hypothalamic-hypophyseal complex as compared to those changes when it was used in combination with vibration. By 4-th month of the experiment these reserves reduced. Gonadotropic activity of the hypophysis has been determined to change in a phase way--from its considerable increase to the norm. The changes in gonadotropic reserves of the hypothalamic-hypophyseal complex were not accompanied by remarkable changes in the gonadal activity.

[The perinatal stress modification of the reactivity of the hypothalamo-hypophyseal-adrenal system]. / Perynatal'na stresova modyfikatsiia reaktyvnosti hipotalamo-hipofizarno-nadnyrkovoï systemy.

The literature data and the results of authors research work concerning long-term effects of prenatal stress and of early postnatal handling on the hypothalamic-pituitary-adrenal stress response are reviewed in the article. Functional state of that system, and the role of hormones, biogenic monoamines and glucocorticoid receptors of the brain in pathogenesis of its alteration are discussed. Special reference is made to gender- and age-related effects of pre- and postnatal stress. The body of evidences supports basic states of the brain hormone-neurotransmitter imprinting during early ontogenesis.

[The neuroendocrine mechanisms of the development of the anovulatory hyperandrogenic syndrome in rats]. / Neiroendokrynni mekhanizmy rozvytku anovuliatornoho syndromu hiperandrohennoho pokhodzhennia u shchuriv.

The anovulatory syndrome in adult female rats occurred after subcutaneous implantation of silastic capsules with testosterone. Acceleration of testosterone conversion into estradiol in the hypothalamus, suppression of pituitary LH responsiveness to LHRH, increase of blood plasma bioactive LH, estrous cycle disorder as well as morphological changes in ovaries demonstrate the alterations in neuroendocrine control of ovulation.

[The function of the reproductive system in x-ray-irradiated male rats after the transplantation of a culture of testicular cells from newborn piglets]. / Stan reproduktyvnoï systemy u renthenoprominenykh samtsiv shchuriv pislia transplantatsiï kul'tury klityn sim'ianykiv novonarodzhenykh porosiat.

The effect exerted by transplantation of the 5 day culture of testicles from newly born piglets on the hypogonadal state of mature X-ray irradiated (3 Gy) rats was studied. It has been found that a month after transplantation (two months after irradiation) the hypogonadal state disappeared for a while, which is confirmed by normalization of the weight of seminal vesicles, content of testosterone and biologically active lutropine, restoration of the reproductive function of rats. No significant changes in steroidogenesis activity have been found, which proves a substituent character of transplantation. The effect disappears three months later but certain restoration of the content of nucleic acids in the testicles is observed.

[The functional organization of the adaptive and compensatory reactions of the endocrine glands]. / Funktsional'na orhanizatsiia adaptatsiinykh i kompensatornykh reaktsii zaloz vnutrishn'oï sekretsiï.

Current concepts of the systemic organization and interrelationship between adaptive and compensatory responses of the endocrine glands and hormone-producing cells are reviewed. Emphasis is made on the involvement of prolactin, insulin endorphins and other neuropeptides into stress responses. A problem of the multihormonal control of physiological functions and role of blood protein carriers and hormonal cytoreceptors in pathogenesis of various diseases are discussed. Special attention is paid to the importance of endocrine function reserves testing for diagnosis of premorbid states and for estimation of human psychophysiological and physical potentials.