Abstract
The localization and changes of fibrinolytic activity during the process of ovulation were investigated by the fibrin slide method. In regular estrous cycle rats, fibrinolytic activity first appeared in the external area of the follicle wall (stigma) at 12hr before ovulation. No activity was noted in the follicular cavity at this time. A peak of activity was seen at 2hr before ovulation. After ovulation, the activity decreased markedly. The activity was completely inhibited on fibrin slides to which 10-2M trans-aminomethyl-cyclohexane carboxylic acid had been added. No activity was observed on plasminogen-free fibrin slides. These results suggest that fibrinolytic activity is one of the important factors involved in the rupture of the mature follicle wall, and that the fibrinolytic activity is due to plasminogen activator activity.