Effects of prostacyclin on ovulation and microvasculature of the in vitro perfused rabbit ovary.
Prostacyclin (prostaglandin I2) methyl ester at 0.1, 1, or 10 micrograms/ml was added to the perfusate of one rabbit ovary every 2 hours for the first 10 hours of perfusion. The contralateral ovary was perfused with medium alone. Prostacyclin methyl ester at 1 and 10 micrograms/ml induced ovulation in the absence of gonadotropin, with ovulatory efficiencies of 26.7% +/- 3.8% and 46.5% +/- 5.0%, respectively. Most ovulated ova (77.4%) did not progress beyond the germinal vesicle stage, and there was no significant degeneration of ovulated ova or follicular oocytes. Examination of the follicular microvasculature 5 hours after exposure to prostacyclin revealed marked vessel dilatation and filling defects at the apex. By 7 hours after prostacyclin exposure, the intrafollicular space contained extravasated resin, reflecting increased vascular permeability. The vascular changes paralleled those previously observed in gonadotropin-induced ovulation. These results indicate that prostacyclin acting locally alters the vascular integrity of the follicle wall and facilitates follicle rupture.
D000818:Animals; D011464:Epoprostenol / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D008833:Microcirculation / Q000187:drug effects / Q000648:ultrastructure; D009865:Oocytes / Q000502:physiology; D010053:Ovary / Q000098:blood supply* / Q000378:metabolism; D010060:Ovulation / Q000187:drug effects*; D011374:Progesterone / Q000096:biosynthesis; D011817:Rabbits
D011374:Progesterone; D011464:Epoprostenol