REGRESSION OF THE OVINE CORPUS LUTEUM AFTER INFUSION OF PROSTAGLANDIN F2α INTO THE OVARIAN ARTERY AND UTERINE VEIN

Abstract

Prostaglandin F2α (PGF2α) is luteolytic in a number of species and the recent finding of endogenous secretion of PGF2α into the utero—ovarian vein of oestrogen-treated guinea-pigs (Blatchley, Donovan, Poyser, Horton, Thompson & Los, 1971) supports the hypothesis that PGF2α is the uterine luteolytic factor. Because the luteolytic effect of the uterus on the corpus luteum is local, it is necessary that a luteolysin secreted by one uterine horn can cause regression of the corpus luteum on the same side. The present experiments were designed to investigate the effect of PGF2α infused into the ovarian artery or uterine vein of the cyclic ewe. Polyvinyl catheters (o.d. 0·8 mm) were inserted into a branch of one ovarian artery and a branch of the uterine vein on the same side in Merino ewes. The other ovary was removed. On day 6, 7, 8 or 9 of the succeeding