[CHANGES IN THE BRAIN TESTOSTERONE METABOLISM AND SEXUAL BEHAVIOR IN MALE RATS PRENATALLY EXPOSED TO METHYLDOPA AND STRESS].

The changes of aromatase and 5α-reductase activities were studied in preoptic area (POA) and medial basal hypothalamus of 10-days-old and sexual behavior in 3-month-old male offsprings of rats exposed daily to noradrenaline antagonist methyldopa (400 mg/kg per os) 30 minutes prior to 1-hour immobilization during the last week of pregnancy (from 15th to 21st day). Prenatal stress caused aromatase activity lowering in the POA of developing brain and feminization (appearance of lordosis) and demasculinization of sexual behavior (prolongation of latent periods to the first mounting and first intromission as well as of the first ejaculation and postejaculation refractory period) in young male offspring. Oral methyldopa used prior to pregnant females stressing prevented early effect of prenatal stress on aromatase activity in the POA and normalized the male sexual behavior in young male rats by shortening both latent period to the first ejaculation and postejaculation refractory period, and an increase of numbers of ejaculation. The data obtained indicate that brain noradrenergic system plays significant role in the mechanisms of metabolic- and behavioral disturbances developing in male rats exposed to prenatal stress.

Assessment of gold nanoparticle effect on prostate cancer LNCaP cells.

UNLABELLED: In recent years gold nanoparticles (AuNPs) have received considerable attention for various biomedical applications including diagnostics and targeted drug delivery. However, more research is still needed to characterize such aspects of their use in clinical oncology as permeability, retention and functional effect on tumor cells. AIMS: This study was designed to describe the effect of non-functionalized AuNPs on LNCaP prostate cancer cells growth. MATERIAL AND METHODS: LNCaP cells were cultured in RPMI-1640 medium containing AuNPs covered by polyvinylpyrrolidone of average size 26.4 nm (10.0 µg/ml). Counts of cells were calculated and their morphology was examined. RESULTS: AuNPs conglomerates have been visualized in cultured cells. After 4-day incubation in presence of AuNPs significant retardation of LNCaP cells growth was observed both in 5α-dihydrotestosterone stimulated and non-stimulated cultures. No morphological changes of live LNCaP cells were seen in any experiment. CONCLUSION: Given absence of morphological changes in live cells and dribble and relatively constant numbers of dead cells, it was concluded that inhibitory effect of AuNPs on LNCaP cells growth was caused by alterations of proliferation.

Cooperative antitumor effect of endothelial-monocyte activating polypeptide II and flutamide on human prostate cancer xenografts.

UNLABELLED: Recombinant cytokine-like endothelial monocyte-activating polypeptide II (EMAP II) and antiandrogen flutamide target different mechanisms of growth of androgen-dependent prostate cancer (PC). The aim of this study was to clarify whether combined treatment with EMAP II and flutamide is more effective than monotherapy with regard to retardation of PC progression. MATERIALS AND METHODS: Antitumor effects of EMAP II (10 µg/kg b.w./d, s.c., 3d), or flutamide (10 mg/kg b.w./d, per os, 3d), or their combination were studied in CBA male mice bearing human androgen-dependent PC xenografts for 7 days. Androgen-dependent phenotype of the tumors was verified in preliminary castrated mice. The xenografts were weighed and underwent a histopathologic examination. The results were compared with those of non-treated mice. RESULTS: EMAP II and flutamide used separately inhibited growth of the xenografts by 74% and 53% respectively. Both drugs caused destructive changes in malignant epithelial cells along with leukocyte infiltration of the tumor. Combined treatment inhibited tumor growth by 85%, and was more effective than monotherapy with regard to morphological changes. CONCLUSIONS: This study demonstrates cooperative inhibitory effect of EMAP II and flutamide on growth and morphology of human PC xenografts that could represent a new modality of palliative treatment of this disease.

[Bioethical aspects of experiments on the animals].

The principles of humane attitude toward laboratory animals, the main rules of defense and application of vertebral animals in scientific investigations, which are coordinated with European convention content, were presented. Recommendations for organization and activities of bioethics committees and commissions, which conduct the expert estimation of scientific investigations, using laboratory animals, were presented.

Prenatal dexamethasone prevents early and long-lasting neuroendocrine and behavioral effects of maternal stress on male offspring.

The hypothesis on the mediating role of hypothalamic-pituitary-adrenocortical (HPA) hormone secretion in neuroendocrine, neurochemical and behavioral alterations generated by prenatal stress in male rat offspring was tested in this study with dexamethasone (Dex) used for suppression of HIPA stress responses. Pregnant dams were being restrained daily for 1 h over the last week of gestation. In male offspring this resulted in attenuation of sex-specific pattern of the protein fractions (on the 5th postnatal day), steroid aromatase activity (on the 10th postnatal day) in the brain preoptic area, and in a decrease of male copulatory behavior, hypothalamic noradrenaline and plasma corticosterone responses to an acute stress, an increase in HPA responses to noradrenergic stimulation and other effects in adulthood. All those changes were prevented with prenatal Dex in a dose of 0.1 mg/kg b.w. injected 30 min prior to restraining pregnant dams. As such, HPA hormone secretion mediates alterations of programming of brain development induced by prenatal stress.

Antitumor effect of endothelial monocyte-activating polypeptide-II on human prostate adenocarcinoma in mouse xenograft model.

UNLABELLED: Endothelial monocyte-activating polypeptide-II (EMAP-II) is a novel proinflammatory cytokine with anti-angiogenic properties. The aim of this work was to evaluate in vivo antitumor activity of EMAP-II in growing human prostate adenocarcinoma xenograft mouse model. MATERIALS AND METHODS: Recombinant human EMAP-II was expressed in Escherichia coli and purified after cleavage with enterokinase (EMAP-II e). EMAP-II preparations were injected to CBA mice bearing subrenal capsule xenografts of human prostate adenocarcinoma. After 3-days treatment, the xenografts were isolated and weighed, then the transplants exposed to EMAP II e (100 or 200 microg/kg b. w.) were examined histologically. RESULTS: EMAP-II administered daily at a dose of 100 or 200 microg/kg b. w. caused striking retardation of local tumor progression as compared to the controls. Low dose (10 microg/kg) was effective in some cases. CONCLUSION: EMAP II exhibits significant antitumor activity in vivo in human prostate adenocarcinoma xenografts in mouse model.

[Sex characteristics of neuroendocrine effects of prenatal exposure to exogenous glucocorticoids].

The effects of hydrocortisone acetate treatment of rats during the last gestational week on neurochemical and morphological characteristics of the brain in early postnatal and mature offspring were studied. Disappearance of sexual differences both in aromatase and 5alpha-reductase activities and noradrenaline concentration in the preoptic area in 10-day old rats was found. Meanwhile a sexual dimorphism in serotonin metabolism emerged. In adult offspring, the prenatal exposure to glucocorticoids resulted in disappearance of sexual differences in neurocytes' nuclei volume in medial preoptic and suprachiasmatic nuclei. The adrenocortical reaction to noradrenaline infusion to the 3rd brain ventricle was absent in the experimental males and intensified in females. In males, adrenocortical reaction to restraint decreased while post-stress changes in hypothalamic noradrenaline concentration and hippocampal glutamate decarboxylase activity were not observed. In the similar experiments in females both the augmentation of adrenocortical reaction and inhibition of GABA-ergic system were revealed. The results obtained indicate the modifying effect of prenatal exposure to glucocorticoids on sexual dimorphism of neuroendocrine system.

Developmental changes in the distribution of corticosteroid-binding globulin in fetal and newborn sheep tissues.

Developmental changes in immunohistochemical localization of corticosteroid-binding globulin (CBG) in fetal and newborn sheep tissues were studied. Tissue samples have been harvested at days 63-64, 100-103, 125-128 and 142-144 of gestation or 2 postnatal days. In the liver, immunoreactive CBG (irCBG) has been identified in hepatocytes. The intensity of CBG staining was highest at 63-64th gestation days and then was lowered gradually down to negligible level in newborn lambs. Within kidney, irCBG was selectively localized to the epithelium of proximal and distal convoluted tubules. Its amount in the course of development followed a pattern similar to that in the liver. By contrast, fetal sheep lung and pancreas demonstrated noticeable rise of irCBG late in gestation. irCBG has been detected in respiratory epithelium of tertiary bronchi, bronchioles and terminal bronchioles, meanwhile alveoli and other lung tissues were CBG-immunonegative. In the pancreas, irCBG staining was associated with acinary cells, whereas Langerhans islets contained no irCBG at all examined stages of pregnancy. Developmental changes in irCBG did not follow reported triphasic profile of fetal sheep plasma CBG concentrations thereby showing the existence of independent cellular mechanisms regulating CBG level in the tissues. Peculiarities of intraorgan distribution and developmental changes in irCBG suggest that intracellular CBG may regulate bioavailable cortisol concentrations in the sheep tissues during fetal and early postnatal life.

Early postnatal effects of prenatal exposure to glucocorticoids on testosterone metabolism and biogenic monoamines in discrete neuroendocrine regions of the rat brain.

We investigated the effects of hydrocortisone acetate and dexamethasone administered to pregnant rats during the last gestational week on sexual differentiation of testosterone metabolism and biogenic monoamine contents and turnover in the discrete brain regions in 10-day-old offspring. In the preoptic area, sex-dependent differences in aromatase activity were attenuated by prenatal glucocorticoids. Prenatal dexamethasone but not hydrocortisone acetate caused the inversion of sexual dimorphism of 5alpha-reductase activity in the preoptic area. In the brain preoptic area of the male pups prenatally exposed to hydrocortisone acetate, a decrease in noradrenaline turnover was found. Dopamine turnover in the preoptic area and 5-hydroxytryptamine metabolism in the preoptic area and medial basal hypothalamus increased in females as a result of hydrocortisone acetate treatment. Our results indicate that excess glucocorticoids in prenatal life modifies the basic neurochemical and neurophysiological mechanisms of sexual brain differentiation and might contribute to behavioral and reproductive disorders in adulthood.

Neuroendocrine mechanisms of development of experimental hyperandrogen-induced anovulation.

An experimental model of hyperandrogen-induced anovulatory infertility (s.c. implantation of Silastic capsules containing testosterone into adult female rats) was used to study morphological, hormonal, and biochemical measures characterizing the state of the hypothalamo-hypophyseal-ovarian system. Impairments in functional androgen metabolism in the hypothalamus were seen, with decreases in the Luliberin sensitivity of the hypophysis, changes in the structure of estral cycles, and morphological changes in the ovaries; these findings are evidence for neuroendocrine disturbances in the control of ovulation. Flutamide, an experimental antiandrogen, led to partial normalization of the hormonal, biochemical, and morphological characteristics, as well as to recovery of fertility in females with anovulatory infertility.

Participation of endogenous opioids in pathogenesis of early neuroendocrine manifestations of prenatal stress syndrome.

We studied sex dimorphism in the content of norepinephrine and activity of enzymes involved in testosterone metabolism in the preoptic hypothalamic area of 10-day-old rats. Prenatal stress eliminated sex-related differences in these indices. These disturbances were absent in rats subjected to prenatal stress under conditions of opioid receptor blockade with naltrexone. These data attests to the important role of opioids in the pathogenesis of prenatal stress syndrome.

Early and long-term neuroendocrine effects of prenatal stress in male and female rats.

The effects of maternal stress, termed prenatal stress (PNS) on the neuroendocrine regulation of reproduction and the stress reactivity of offspring were studied in rats. PNS prevented the formation of sexual dimorphism in catecholamine levels, aromatase activity, and androgen 5alpha-reductase activity in the preoptic area of the brain and the mediobasal hypothalamus in 10-day-old rats. The morphological correlate of the functional lesions induced by PNS consisted of the elimination of gender-related differences in the volumes of neuron nuclei in the suprachiasmatic nucleus. Prenatal stress altered the stress and adrenergic reactivities of the hypothalamo-hypophyseal-adrenal system in mature males and females. The long-term effects of PNS were regarded as a consequence of the disruption of the hormone-neurotransmitter imprinting of the neuroendocrine system.

Prenatal stress and glucocorticoid effects on the developing gender-related brain.

Hormonal and neurotransmitter environment of nondifferentiated cells in the developing brain determines many of gender-specific behavioural and neuroendocrine functions. Early postnatal and long-term effects of maternal stress or prenatal glucocorticoid on sex-related peculiarities of the brain morphology, biogenic monoamine turnover, testosterone metabolism, hypothalamic noradrenaline (NA) and adrenocortical responses to an acute stress were studied in Wistar rat offsprings. Maternal stress (1 h immobilization daily for gestational days 15-21) prevented development of sexual dimorphism in neuronal cell nuclei volumes in suprachiazmatic nucleus (SCN) in 10 day old pups. That was associated with a disappearance of male female differences in NA and 5-hydroxytryptamine turnover in the preoptic area (POA) and dopamine (DA) turnover in the mediobasal hypothalamus (MBH) by decreasing them in male pups. Hydrocortisone acetate (5 mg daily during the last week of pregnancy) produced changes in NA turnover in the POA of males and females which were quite similar to those after maternal stress. Changes in aromatase and 5alpha-reductase activities in the POA of male pups were quite opposite as affected by maternal stress or prenatal glucocorticoid. Sexual differences in 5alpha-reductase activity in the MBH appeared due to its increase in prenatally stressed male pups. In contrast to adult males, in adult females maternal stress did not restrict hypothalamic NA and blood plasma corticosterone response to acute stress (1 h immobilization). Our findings on morphology and functions of gender-related developing brain areas stand in correlation with modifying effects of maternal stress and prenatal glucocorticoid on behavior and neuroendocrine regulations.

Endocrine mechanisms of suppressive effect of low dose estrogen-antiandrogen treatment on androgen-dependent organs of male rats.

The effects of low doses of hexestrol (Hex) (2-40 micrograms/kg bw) and flutamide (FI) (10 mg/kg bw) on some endocrine mechanisms in mature intact male rats are described in the present paper. It has been shown that each preparation, administered separately for 10 days, induced a moderate decrease in the weight of the ventral prostate (VP), anterior prostate lobe or coagulating gland (CG) and seminal vesicles (SV), in the DNA content and number of cells in the VP. 5 alpha-reductase activity was also decreased; the epithelium secretory activity of the VP was suppressed. After combined FI (10 mg/kg bw) and Hex (40 micrograms/kg bw) the following castration-like effects were observed: an abrupt fall in the weight of the accessory sexual glands, a decrease of DNA level and cell number in the VP as well as a suppression of the production of 5 alpha-reductase metabolites in this structure. Histologically, a marked degenerative changes in the VP secretory epithelium was observed; on the contrary an hyperplasia of connective and smooth muscle cells was evident. When FI alone was administered to rat, the above-mentioned changes were accompanied by a pronounced elevation of plasma bio-LH and testosterone (T) levels, also an increase of testicular delta 5-3 beta-hydroxysteroid dehydrogenase activity was observed. On the contrary, when Hex was administered alone or in combination with FI, bio-LH and T levels and enzyme activity decreased. We conclude that Hex administration in low doses, in combination with FI, could be an alternative method for a complete androgen blockade of the accessory sexual glands.

[The effect of prenatal stress on the development of hypophyseal gonadotropic function in male rats]. / Vliianie prenatal'nogo stressa na stanovlenie gonadotropnoi funktsii gipofiza u samtsov krys.

Significant changes of the aromatase and 5 alpha-reductase hypothalamic activity were found in juvenile prenatally stressed male Wistar rats. The blood plasma testosterone level increased following niftolide (NF) or 1, 4, 6-androstatine-3, 17-dione (ATD) administration. Prenatal stress seems to exert a modifying effect upon the regulating mechanisms of the pituitary gonadotropin function, lowering the functional reserves of the hypothalamo-hypophyseal-testicular axis in pre- and postpubertal male rats.

[Recovery of various parameters of the functional state of the reproductive system in thymectomized rats as affected by thymic membrane factor]. / Vosstanovlenie nekotorykh pokazatelei funktsional'nogo sostoianiia reproduktivnoi sistemy u timéktomirovannykh krys pod vliianiem membrannogo faktora timusa.

Ten-month-old male rats thymectomized in early post-puberty were ascertained to have lower plasma luteinizing and testicular hormones and higher testicular steroid dehydrogenase activity. Following 24 hours of administration of a thymocyte membrane structural agent, pituitary gonadotropic and gonadal androgenic functions became normal. There was no agreement between the hormonal parameters and the levels of nucleic acids in the testes and prostate.

Early postnatal changes in sexual dimorphism of catecholamine and indoleamine content in the brain of prenatally stressed rats.

Sexual dimorphism in catecholamine and indoleamine content in the brain preoptic area and mediobasal hypothalamus was studied in 10-day-old rat pups whose mothers had been exposed to the daily 1-h immobilization stress during the last week of pregnancy. Concentration of noradrenaline in the preoptic area and 5-hydroxyindoleacetic acid in the mediobasal hypothalamus of the prenatally stressed male offspring as well as dopamine content in the mediobasal hypothalamus and 5-hydroxyindoleacetic acid content in the preoptic area of the females were increased by 59%, 45%, 34%, 76%, respectively. Dopamine content in the preoptic area of the female pups was decreased. In addition, an increase of 5-hydroxytryptamine metabolism in the female preoptic area has been revealed. As a result of prenatal stress, sex-related differences in noradrenaline and 5-hydroxyindoleacetic acid concentrations in the preoptic area and those in dopamine concentration in the mediobasal hypothalamus disappeared. The suggestion is made that the early changes in sexual dimorphism of the brain catecholamines and 5-hydroxytryptamine metabolism in prenatally stressed rats may be responsible for the development of the long-term disorders of sexual differentiation of the neuroendocrine functions.

Catecholamines in steroid-dependent brain development.

UNLABELLED: Sex-specific peculiarities of catecholamine (CA) content and turnover in neuroendocrine brain areas and their modification with neonatal steroids or prenatal stress (PS) in Wistar rats were studied. No changes in noradrenaline (NA) content and turnover rate were found in the preoptic area (POA), meanwhile dopamine (DA) turnover rates in the POA and mediobasal hypothalamus (MBH) were increased in neonatally androgenized 10-day-old females. Treatment of female neonates with various catecholestrogens increased hypothalamic NA content by 30-95% but only 4-hydroxyestradiol-17 beta induced anovulation. 6-Hydroxydopamine had no significant impact on hypothalamic CA content in neonates and did not prevent testosterone-induced persistent estrous. Maternal stress (restriction for 1 h a day, 15-21st days of pregnancy) resulted in a decrease of hypothalamic NA and blood plasma corticosterone response to acute stress in adult male offspring. Sex differences in CA content in the POA and MBH disappeared in 10-day-old prenatally stressed rats. CONCLUSIONS: (1) sexual brain differentiation needs co-operative actions of sex steroids and CA to be completed; and (2) early changes in CA content and turnover induced by PS or neonatal steroid exposure predetermine long-term alterations of the stress responsiveness, reproductive behaviour and neuroendocrine control of ovulation.

[Effect of 131I incorporation on the status of the reproductive system in male rats and the dose-dependent effect]. / Vliianie inkorporatsii 131I na sostoianie reproduktivnoi sistemy samtsov krys dozozavisimogo éffekta.

Radioactive 131I was injected in single doses 9.25, 37, and 92.5 kBq to prepubertal (30-day-old) male rats. Iodine incorporation in doses 37 and 92.5 kBq resulted in some functional changes in the reproductive system of mature rats: blood testosterone level increased, its hypothalamic aromatization intensified, and biologically active LH level in the blood dropped. Incorporation of 9.25 kBq of 131I had no effect on male reproductive system. A possibility of direct injury to rat testicles by 131I incorporation is suggested.