The effect of prostaglandin F_2α on ovarian blood flow and corpora lutea regression in the rabbit

Abstract

IN many species luteolysis is dependent upon the presence of the uterus and an intact utero-ovarian vasculature. The occurrence of prostaglandin F_2α (PGF_2α) in uterine tissue, its specific venoconstrictor properties and its ability to induce luteolysis exogenously, led to the hypothesis that, its release by the uterus might cause luteolysis by constricting the uterine and utero-ovarian veins and reducing ovarian bloood flow¹. The observation that total ovarian venous outflow fell during infusions of PGF_2α in rats and rabbits (after laparotomy and ovarian vein cannulation) supported this hypothesis. A subsequent investigation using similar methods failed to confirm this in rats². Experiments in sheep with ovaries and uterus transplanted in toto to the neck produced no unequivocal evidence for a drop in ovarian blood flow following doses of PGF_2α producing luteolysis, at least until oestrus ensued³. With increasing doses however, an immediate fall in ovarian blood flow occurred⁴.