Résumé
To determine if prostaglandins [PGs] have a direct effect on the ovarian proteolytic enzyme system the ultrastructure of the follicle wall and the microvasculature in the presence and absence of indomethacin were examined. Nine hours after administration of human chorionic gonadotropin [hCH] or hCG plus indomethacin, ovaries were removed and processed for microscopic examination. Also, rabbit ovaries were induced to ovulate with PGF2 [100 ng/ml] in the presence and absence of tranexamic acid [0.1, 1.0 or 10 mM], a plasminogen activator inhibitor. From this study, it was found that the addition of indomethacin to hGG inhibited ovulation and production of PGs without affecting the follicular microvasculature. However, the changes in follicle wall architecture were less pronounced after treatment with indomethacin. Ovulatory efficiency in response to PGF2 2alpha [the percence of follicles >1.5 mm that ovulate] was significantly reduced [P <0.01] by mM tranexamic acid. These results suggest that PGs induce follicular rupture by activation of proteolytic enzymes located in the folicle wall
Sujets)
Prostaglandines/pharmacologie , Indométacine/pharmacologie , LapinsRésumé
This study demonstrated that acute immobilization stress induced suppression in testosterone and elevation in cortisol levels in plasma of albino rats. The rise in cortisol is partially responsible for the declining in the testosterone concentrations. High serum level of glucocorticoids impaired directly the testicular function, decreased the sensitivity of pituitary gland to LHRH and reduced the hypothalamic release of LHRH. On the other hand, chronic immobilization stress, noisy test and harmony sounds induced a decrease in both testosterone and cortisol plasma levels. This indicated that other mechanisms were implicated in the suppression of testosterone level included the inhibition of the hypothalamic pituitary gonadal axis by increased prolactin secretion and the release of endogenous opioid peptides