Prostaglandins in swine reproduction

A review is presented of the roles of prostaglandins in swine reproduction. PGE and PGF are both produced in the ovary. PGE is thought to mediate steroidogenic activity of L.H. on the development of the granulosa cells leading to increased progesterone production in the preovulatory phase of the oestrus cycle. PGF2 acts on the theca cells leading to increased oestradiol and oestrus manifestation. The PG blocker indomethacin prevents oocyte rupture, but not maturation. The L.H. surges in the follicular phase stimulate ovarian PG production which initiates oestrus and ovulation. The uterus produces PGF2alpha. Disorders leading to abortion usually result in excess PGF2alpha production at the endometrium leading to luteolysis. With normal gestation circulatory progesterone levels fall during the last two weeks of pregnancy associated with increased circulatory foetal corticoid levels. The foetal corticoids are thought to trigger endometrial PGF2alpha levels leading to luteolysis and parturition. The use of exogenous PGF2alpha for induction of oestrus and abortion, parturition, semen collection and resolution of anoestrus is reviewed.