[Prolyl hydroxylase activity in rabbit ovary during ovulatory process].

The disruption of connective tissue and dissociation of collagen fibers that occurs in the ovarian follicle during mammalian ovulation is reportedly induced by collagenolytic enzymes. To further analyse the metabolism of ovarian collagen during the ovulatory process, prolyl hydroxylase activity was assayed because the quantity of this enzyme provides some indication of the relative amount of collagen fibrillogenesis in connective tissues. Following the induction of ovulation by hCG, prolyl hydroxylase activity increased in both the ovarian follicle and stroma. The amount of activity reached a maximum of about 300% above the control level at 13hr after hCG, i.e., 1-3hr after the estimated time of ovulation. The pattern of enzyme activity during the ovulatory process was identical in both the follicle and the stroma. The prolyl hydroxylase activity remained at more than 200% above the control level throughout the secretory phase. It is concluded that the rabbit ovarian follicle and stroma contain prolyl hydroxylase activity, and that this enzyme activity increases significantly during the ovulatory process and luteinization.