Failure of aspirin to modify the hypotensive action of captopril in spontaneously hypertensive rats.

Abstract

1. Oral administration of the angiotensin converting enzyme inhibitor, captopril (30 mg/kg per day) to spontaneously hypertensive rats of the Okamoto strain progressively reduced arterial blood pressure by 60 mmHg over 4-5 days. 2. Oral treatment of spontaneously hypertensive rats with aspirin (200 mg/kg per day) for one week did not alter blood pressure, but it greatly reduced the vasodepressor effects of intravenous injections of arachidonic acid (3 mg/kg). 3. The fall in blood pressure of spontaneously hypertensive rats treated concurrently with both aspirin (200 mg/kg per day) and captopril (30 mg/kg per day) was not different to the fall observed in rats treated with captopril alone. 4...