[Activities of collagenolytic enzymes in the human ovary (author's transl)]

To elucidate the mechanisms of follicular rupture at ovulation in human, activities of collagenolytic enzymes were measured in the human follicles at various stages of development by using two kinds of synthetic substrates, alpha-N-benzoyl-DL-arginine-2-naphthylamide HCl and N-carbobenzoxy-glycyl-prolyl-glycyl-glycyl-prolyl-alanine. The result clarified that human ovaries did have two kinds of collagenolytic activities, one cathepsin B1 with its optimal pH 6.0, the other neutral collagenase with its optimal pH 7.5. To examine the subtle changes of these enzymatic activities in the follicles during ovulatory processes, the follicle wall was dissected into three parts, namely, the granulosal layer, the apical wall and the basal wall without the granulosal layer. Activity of neutral collagenase presented a continuous increase in the follicular wall, while in the granulosal layer its gradual depletion was observed. Cathepsin B1 revealed a significant drop of its activity in the apical wall around a preovulatory period. These results indicate an involvement of collagenolytic enzymes in the human ovulatory process.