Renal hypertension following aortic constriction is abolished by angiotensin II converting enzyme inhibitor, but not by low-salt diet.

This study evaluates the role of different sodium intakes and the role of angiotensin II in the development and the maintenance of renovascular hypertension in rats with constriction of the aorta proximal to the renal arteries. The rats were studied 3 weeks after surgery when the hypertension was well established. Glomerular filtration rate was decreased and filtration fraction was increased in rats with proximal aortic constriction. Low and high salt intakes had no effect on glomerular filtration and filtration fraction. Treatment with angiotensin II converting enzyme inhibitor increased the glomerular filtration rate and reduced the filtration fraction in rats with proximal aortic constriction to the same levels as in control rats. Serum levels of angiotensin II were about the same in rats with proximal aortic constriction as in control rats. Conclusion. The renovascular hypertension in proximal aortic constriction is influenced by locally formed angiotension II but not by alterations in salt intake.