The effects of prostaglandin E1 and sodium meclofenamate on blood pressure in renal hypertensive rats.

Conflicting evidence exists regarding the ability of PGE1 to normalize blood pressure in renal hypertensive rats. We performed experiments to determine the effect of PGE1 (15 mug/kg i.p. daily for 3 weeks) in renal hypertensive Wistars and found no significant change in systolic pressure. A higher dose (150 mug/kg i.p.) lowered pressure after 14 days of treatment, but not back to control levels. Further investigations are required to establish the mechanism whereby PGE1 evokes this fall. To test the hypothesis that endogenous prostaglandins have a hypotensive function in renal hypertension, experiments were performed using sodium meclofenamate to inhibit prostaglandin biosynthesis. In chronic hypertensive rats the drug had no significant effect, while in the acute phase of renal hypertension there was a dose-dependent inhibition of the pressure rise. The possibility is suggested that prostaglandins may initiate or sustain the acute phase of renal hypertension in rats.