Antagonism by PGF2alpha of the vasodilation induced by PGE1, PGE2 and PGA1 in the canine uterus.

Prostaglandins appear to play an important role in a number of reproductive processes. The present study was designed to determine if the vasodilator action of prostaglandins of the A and E series on uterine vascular smooth muscle was mediated via a receptor and if PGF2alpha could compete for this same receptor. The data demonstrate that PGF2alpha, which by itself has no uterine vascular effect, can produce a parallel shift in the dose-response curves for certain vasodilator prostaglandins. This action, which suggests competitive antagonism, may well play a role in regulating blood flow in the nonpregnant uterus.