SECRETION OF PLASMINOGEN-ACTIVATOR INHIBITOR TYPE-1 BY CULTURED OVARIAN-CELLS OBTAINED FROM GONADOTROPIN-TREATED IMMATURE RATS

It is demonstrated that i) theca-interstitial compartment synthesizes the majority of plasminogen activator inhibitor type 1 (PAI-1) in the ovary before ovulation, and the follicular wall may therefore serve as a specific barrier with the presence of PAI-1 activity to prevent the secretion of tPA into the extrafollicular compartments; ii) granulosa cells secrete only a small amount of ovarian PAI-1, but synthesize th e most of tissue-type plasminogen activator tPA involved in the proces ses leading to ovulation; iii) since only matured cumulus-oocyte compl exes secrete a large amount of tPA and PAI-1, both tPA and PAI-1 activ ity in the conditioned medium may be used as reliable markers for eval uating oocyte quality for in vitro fertilization.