Prostaglandin-induced apoptosis of ovarian surface epithelial cells

In a previous study we observed that expression of mRNA encoding prostaglandin endoperoxide synthase is elevated within ovarian epithelial cells that cover the surface of preovulatory ovine follicles. We report herein that during the process of ovulation these cells undergo degenerative morphological changes typical of apoptosis and are sloughed from the follicular apex. This response was circumvented by blockade of ovulation by indomethacin. The effect of indomethacin was reversed by prostaglandin E2 or F2 alpha. Prostaglandin-induced DNA fragmentation (a hallmark of apoptosis) was verified in primary cultures of sheep ovarian surface epithelial cells. Prostaglandins did not cause apoptosis in a human ovarian cancer cell line of epithelial origin.