Efeitos da endotelina-1 sobre a esteroidogênese e o crescimento celular em cultura de células da granulosa de bovinos

Além do controle neuroendócrino do eixo hipotalâmico-hipofisário-gonadal existem fatores autócrinos e parácrinos que controlam o crescimento, seleção e ovulação nos mamíferos. Estes fatores ainda não estão bem estabelecidos. Objetivando analisar as variações nas concentrações plasmáticas da endotelina-1 em um ciclo estral bovino e seus efeitos sobre o cultivo de células da granulosa, foram analisadas amostras plasmáticas de 5 dias (0, 1, 3, 7 e 13) de um ciclo estral, tendo como base o dia da ovulação (dia 0) e 3 horas (8, 13 e 16) do 14º dia do ciclo. As variações nas concentrações plasmáticas de endotelina-1 não foram significativas para os dias assim como para as horas do dia analisado. Células da granulosa obtidas de folículos antrais foram cultivadas durante 48 horas com diferentes concentrações de endotelina. Os resultados demonstraram que a endotelina atua de maneira dose-dependente estimulando a produção de progesterona e inibindo o crescimento celular.Besides the neuroendocrine control of the hypotalamic-hypophisary-gonodal axis there are autocrines and paracrines factors that control the growth, selection and ovulation in the mammals. These factors are not well established yet. Aiming to analyze the variations in the endotelin-1plasmatic concentrations in a bovine estral cycle and their effects on the culture of granulosa cells, plasma samples of 5 days (0,1,3,7 and 13) from an estral cycle have been analyzed, having as basis the ovulation day (day 0) and 3 hours (8,13,16) of the fourteenth day of the cycle. The variations in the endothelin-1 concentrations were not significant for the days as well as for the hours of the analyzed day. Granulosa cells obtained from antral follicles were cultivated during 24 hours with different concentrations of endothelin. The results demonstrated that the endothelin-1 acts in a dose-dependent manner stimulating the production of progesterone and inhibiting the cellular growth

Hypoxic and hypercapnic ventilatory responses in rats with polycystic ovaries

In female rats, a single injection of estradiol valerate (EV) results in effects that are similar to those observed in women with polycystic ovary syndrome (PCOS). We hypothesized that EV-induced PCOS affects breathing control based on evidence showing an influence of sex hormones on ventilation. To test this hypothesis, we studied the effects of EV treatment on the ventilation of female rats in air, in 7% CO2 and in 7% O2, at 30, 45 and 60 days after EV injection. The group examined 30 days after EV treatment showed a 61% reduction in the hypercapnic ventilatory response compared to the control group. Basal ventilation, hypoxic ventilatory response, and body temperature were not affected. These results, suggest that the hormonal changes observed in PCOS may result in a temporary inhibition of the central chemoreflex but do not influence basal ventilation or the hypoxic peripheral chemoreflex