[Significance of fibrinolysis in ovulation]

To elucidate the significance of fibrinolytic enzymes in ovulation, the changes in the levels of plasminogen activator, plasminogen and plasmin activity were examined using prepubertal rats and sows treated with PMS and hCG. The following results were obtained. 1) The superovulation in rats was blocked with antifibrinolytic agents. 2) Plasminogen and plasminogen activator in the supernatant of rat ovarian homogenates increased toward ovulation. But plasmin activity did not show the significant change. 3) When the superovulation of the rats was blocked with indomethacin, plasminogen remained constant, but plasminogen activator was almost affected. 4) In the supernatant of follicle wall homogenates and the follicular fluid of sows, plasminogen decreased, but plasmin activity increased toward ovulation. 5) Plasminogen activator was produced by rat ovarian granulosa cells, but hCG, gonadotropins, prostaglandins and indomethacin did not activate the production of plasminogen activator in the granulosa cells.