Effects of Chronic Therapy with Cilazapril, a New Angiotensin-Converting Enzyme Inhibitor, on Regional Blood Flows in Conscious Spontaneously Hypertensive Rats

Cilazapril is a new potent inhibitor of the angiotensin-converting enzyme. The purpose of the present study was to evaluate the effects of chronic treatment with cilazapril on hemodynamics and regional blood flows in spontaneously hypertensive rats. Cilazapril or distilled water was given by gavage for 9 weeks to hypertensive rats at a dose of 10 mg/kg/day, and arterial blood pressure was monitored each week by an indirect method. After the 9 weeks of treatment, blood pressure was measured by a direct method, and regional blood flows, regional vascular resistances, and cardiac output and its distribution were measured with the radioactive microsphere technique. The cilazapril-treated group was compared with the group that received distilled water. Cilazapril had a very pronounced antihypertensive effect which was due to a general peripheral vasodilatation. The regional vascular resistances were decreased in all the organs except the heart. Cardiac output was unchanged, as well as its distribution. Heart rate was lower in the cilazapril-treated group than in the control group. Cardiac hypertrophy was reduced by cilazapril. We conclude that cilazapril is an antihypertensive agent which acts by dilating most of the peripheral vascular beds and which reduces cardiac hypertrophy.