The role of the renin--angiotensin system in experimental renal hypertension in dogs.

Abstract

SummaryAn angiotensin II antagonist, l-sarcosine-8-alanine-angiotensin II, was infused intravenously into conscious dogs with experimental hypertension produced by renal artery constriction and unilateral nephrectomy. In dogs with malignant hypertension and elevated plasma renin activity, a decrease in arterial pressure was observed during infusion of the angiotensin II analog. However, in dogs that developed chronic hypertension of 2–7 weeks duration no decreases in arterial pressure occurred during infusion of this angiotensin II antagonist. Similarly, infusion of this compound into normal conscious dogs did not decrease arterial pressure. It is suggested that angiotensin II acts on receptors in arteriolar smooth muscle to increase peripheral resistance and arterial pressure in dogs with malignant hypertension, but chronic hypertension in the dog is maintained by other mechanisms.