Age dependence of human plasma renin substrate

Abstract

Renin substrate (angiotensinogen) was measured with an assay employing exhaustive incubation of plasma with purified human kidney renin and radioimmunoassay of the angiotensin I (AI) generated. Plasma renin substrate concentration was higher at the age of 3 days (females: 2028 ± 551, males: 1951 ± 565 μg AI/1, mean±SD) than in age group 0–15 years (females: 1513± 555, males: 1263±392μg AI/1). Plasma renin substrate concentration at the age over 15 years (females: 1780±464, males 1752±321 μg AI/1) was higher than in children 0–15 years. Expectedly, high concentrations of plasma renin substrate were found in pregnant women at term (4127 ± 1961 μg AI/1).