Enzyme-induced rupture of rabbit Graafian follicle

Abstract
The mechanism of ovulation has been further examined by utilization of a model based on enzymically induced rupture of the follicle. One to two microliters of aqueous solutions of various proteolytic enzymes were injected into estrous-stage (fully developed with antrum—preovulatory) follicles on the surface of exteriorized rabbit ovaries maintained at body temperature. Preparations of bacterial collagenase or the proteases pronase and nagarse induced changes in the follicle similar to those seen during normal ovulation. One microliter of a 10% solution of collagenase was approximately the amount capable of inducing rupture. With this amount of collagenase the average time between injection and rupture was 10 min, with a range from 2 to 20 min. The pressure changes during induced rupture were comparable to those observed during coitally induced ovulation. The similarity between enzyme-induced rupture and coitally induced ovulation suggests that the structural changes preceding normal rupture of the wall of the Graafian follicle may be the consequence of proteolysis.