Angiotensin blood levels in dogs with experimental renal hypertension

A modified method for estimation of angiotensin in blood is described and its reliability is discussed. Angiotensin blood levels (ABL) were determined in normal dogs. After an intravenous injection of different doses of renin, an excellent correlation was obtained between blood pressure increases and ABL. After severe clamping of the renal arteries in 20 dogs, inconsistent increases in ABL were detected. In several of these animals distinct increases in blood pressure were seen with normal or undetectable ABL. Eight chronic renal hypertensive dogs repeatedly showed normal ABL. It appears, therefore, that an increase in ABL is not essential for the production of acute malignant or chronic benign renal hypertension.