Endocrine Active Compounds Actions during Neonatal Period: Effect on the Ovary

Many female reproductive disorders observed during adulthood originate from the neonatal period, which is a critical stage toward the reproductive potency. Human and animal fertility are determined by the pool of primordial follicles that are established during fetal or neonatal life. The earliest stages of follicle development are under control of a variety of factors, including sex steroids. Neonatal period is a “critical developmental window” in which organisms are susceptible to the environmental chemicals that may affect the reproductive health. Endocrine active compounds (EACs) are found abundantly in the environment and interfere with sex steroids (predominantly androgens and estrogens) by either mimicking or blocking their functions. This review covers the current knowledge about the effects of selected EACs with androgenic (testosterone propionate), anti-androgenic (flutamide), estrogenic (diethylstilbestrol, bisphenol A, 4-tert-octylphenol, phtalates and genistein), anti-estrogenic (ICI 182,780 and parabens), or mixed activity (methoxychlor) on the ovary of neonates, focusing on their effects on the early stages of folliculogenesis. These chemicals have been shown to affect oocyte survival, follicle formation, and growth, as well as steroidogenic functions. The better cognition of mechanisms underlying the long-term consequences of the neonatal EACs exposure may in future lead to an understanding of human health risks and developing prevention strategies

The impact of antiandrogen flutamide on the hypoxia inducible factor 1a and vascular endothelial growth factor A gene and protein expression in the pig placenta during late pregnancy

Introduction. In contrast to estradiol action, little is known about androgen signaling in placental development. The purpose of this study was to evaluate the impact of diminished androgen action on hypoxia inducible factor 1a (HIF-1a) and vascular endothelial growth factor A (VEGFA) protein expression as well as their mRNAs in the structures of fetal and maternal parts of porcine placenta during late pregnancy. Material and methods. Pregnant pigs were injected daily with antiandrogen flutamide, at a dose of 50 mg/kg body weight at different stages of pregnancy: between gestational days 83–89 (90 dpc) and 101–107 (108 dpc). Control groups (90 dpc or 108 dpc) were treated with vehicle (corn oil). One day after the last injection animals were sacrificed and tissues were collected. Tissue samples were frozen for mRNA isolation or fixed for immu­nohistochemistry (IHC). The expression of HIF-1a and VEGFA were investigated by real-time PCR and IHC. Results. Flutamide treatment caused changes in both HIF-1a and VEGFA mRNA levels only in the placentas of the 90 dpc group. Relative optical density analysis showed decreased HIF-1a and increased VEGFA protein expression in the placentas obtained from flutamide-treated 108 dpc group while no differences were observed in the 90 dpc group. Conclusions. Experimentally induced androgen deficiency in pigs deregulates the expression of some genes important for placental blood circulation. We suggest that androgens are involved in the control of expression of HIF-1a and VEGFA in porcine placenta during late pregnancy

The impact of antiandrogen 2-hydroxyflutamide on the expression of steroidogenic enzymes in cultured porcine ovarian follicles

We used our model system for agonism and antagonism of the androgen receptor (AR), in which the porcine ovarian follicles were exposed on the excessive concentration of an AR agonist- testosterone (T) or an AR antagonist- 2-hydroxyflutamide (2-Hf) to: (1) analyze the spatiotemporal expression of ovarian 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), cytochrome P450 17 alpha-hydroxylase/c17,20-lyase (P450c17) and cytochrome P450 aromatase (P450arom); (2) to determine the contribution of AR-mediated action during steroidogenesis and (3) to establish some correlations between the onset and expression pattern of the investigated proteins. Whole follicles (6-8 mm in diameter) isolated from mature porcine ovaries have been incubated (for 24 h) in an organ culture system in the presence of T (10(-7) M), 2-Hf (1.7 x 10(-4) M) or both T and 2-hydroxyflutamide (T+2-Hf, at the same concentrations as when added separately). Thereafter, sections obtained from cultured follicles were processed for main steroidogenic enzymes detection by immunohistochemistry. Moreover, expression of their mRNA and protein was determined by real-time PCR and Western blot analysis. Progesterone, androgens and estradiol concentrations in the culture media were measured by radioimmunoassays (RIA). Our results demonstrated that 2-Hf can influence the steroidogenic activity of porcine follicles in vitro through the blockade of AR. It was shown that follicular 2-Hf treatment brought about dramatic decline in the production of the investigated steroids. What is more the addition of 2-Hf separately caused a negative effect on 3 beta-HSD and P450c17 mRNA and protein expression by ovarian follicles, while it was without effect on P450arom mRNA level. Quite opposite effect was observed in case of the simultaneous addition of 2-Hf and T. It caused high increase, in both P450arom mRNA and its protein. What was interesting, addition T+2-Hf evoked 3 beta-HSD and P450c17 increase on mRNA level, but decreased their protein expression. This was against our expectations but the reason for that finding remains undiscovered, intriguing and worth reporting. These results suggest that alike, steroidogenic enzymes activity and their expression is associated with the presence of androgens and AR in the porcine ovary