EFFECTS OF ANTIHYPERTENSIVE TREATMENT ON SYSTOLIC BLOOD-PRESSURE AND RENIN IN EXPERIMENTAL-HYPERTENSION IN RATS

Abstract

The effects of pretreatment with hydralazine and .alpha.-methyldopa were assessed in rats made hypertensive by ligation of the left renal artery (LRA). Systolic blood pressure and peripheral renin activity (PRA) were measured at 7 days and 1 day before LRA, and at 2, 7 and 28 days after LRA. Systolic blood pressure increased 2 days after LRA in control and .alpha.-methyldopa-treated rats but not in the hydralazine-treated rats. PRA levels did not correlate with changes in systolic blood pressure. PRA first increased 7 days after LRA but decreased 28 days after LRA despite persistent hypertension in controls and .alpha.-methyldopa-treated rats. Factors other than renin are involved in the initial and maintenance phases of this experimental model. Hydralazine protects the rat with LRA from developing hypertension.