Role of Prostaglandins

mone (LH). The increase in rats is preceded by increases in ovarian levels of cyclic AMP and progesterone. Systemic administration of indomethacin prevented the increase of ovarian prostaglandin F and blocked ovulation in rabbits and rats. Intrafollicular injection of indomethacin, in rabbits, at dosages which were ineffective when given via systemic injection, blocked the elevation of follicular prostaglandins and ovulation. Prostaglandin F2! antiserum also blocked LH-induced ovulation when injected intrafollicularly. Intrafollicular injection of prostaglandin F2« , in rabbits in the absence of LH resulted in release of ova from 40 p. ioo of injected follicles, and in resumption of meiotic division of obcytes in go p. 100 of injected follicles. Prostaglandin E2 was much less effective. These results provide evidence in support of a physiologic role of follicular prostaglandin F20c in the process of ovulation and oocyte maturation in response to LH.