Factors Which Influence Ovulatory Degradation of Rabbit Ovarian Follicles

Ovarian follicles contain at least two “collagenolytic” enzymes that can be detected by an assay in which follicular tissue is cultured on gels composed of reconstituted collagen. One enzyme is most active at pH 5.5 (with a range of 4.0–6.8), and is detectable within 10–15 h after tissue incubation. The other enzyme is active at physiological pH (7.0–7.8), but requires approximately 30 h of incubation before the collagen gels begin to exhibit digestion. Both enzymes are present in appreciable amounts in mature Graafian follicles. They are inhibited by EDTA, alpha2-macroglobulin, fetal calf serum, rabbit serum, and high concentrations of ascorbic acid. Chloroquine inhibits the activity at pH 7.4, but does not affect the enzyme that is active at pH 5.5. Neither enzyme is distinctly inhibited by cysteine, trypsin inhibitor (Kunitz), ceruloplasmin, indomethacin, or alpha1-antitrypsin. In consideration of various ovarian factors which may influence the expression of this collagenolytic activity, it is concluded that these enzymes could be active in the digestion of the follicle wall during ovulation.