The hemodynamic effects of prostaglandins in the rat. Evidence for important species variation in renovascular responses.

The hemodynamic effects of prostaglandins E2, F2alpha, D2, and I2, and of indomethacin and arachidonic acid were studied in Sprague-Dawley rats, by means of the radioactive microsphere technique. In contrast to effects in other species, PGE2, PGD2, and arachidonic acid were renal vasoconstrictors in the rat, although PGE2 and arachidonic acid reduced total vascular resistance. PGF2alpha and indomethacin had no effect on the renal vasculature, but PGI2 produced renal and systemic vasodilation. These data indicate that if prostaglandin-mediated renal vasodilation occurs in the rat, PGI2 may be the substance responsible. In view of the species differences in renal vascular responses to the prostaglandins, the rat may not be an appropriate model for study of the prostaglandin system as it relates to other species.