Type IV collagenolytic activity in human preovulatory follicular fluid.

During normal ovulation, the two basement membrane layers of the ovarian follicle are degraded locally. The main component of basement membranes is type IV collagen, which is specifically cleaved by type IV collagenase. According to our results, type IV collagenolytic activity is present within follicular fluid and increases toward ovulation, decreasing rapidly as the follicles rupture. These results suggest that importance of type IV collagenolytic activity in the ovulatory process.