Activity of [Des-Aspartyl¹]-Angiotensin II and Angiotensin II in Man: DIFFERENCES IN BLOOD PRESSURE AND ADRENOCORTICAL RESPONSES DURING NORMAL AND LOW SODIUM INTAKE

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Abstract

This study was designed to compare the effect of [des-Aspartyl1]-angiotensin II ([des-Asp]-A II) and angiotensin II (A II) on blood pressure and aldosterone production in man under conditions of normal and low sodium (Na) intake. Seven normal male subjects in balance on constant normal Na intake (UNa V 160.3±5.0 meq/24 h) for 5 days received A II and [des-Asp]-A II infusions on two consecutive days; 1 mo later they were restudied after 5 days of low Na intake (UNa V 10.5±1.6 meq/24 h). Each dose was infused for 30 min, sequentially. During normal Na intake, [des-Asp]-A II from 2 to 18 pmol/kg per min increased mean blood pressure from 85.2±3 to 95.3±5 mm Hg and plasma aldosterone concentration from 5.2±1.1 to 14.3±1.9 ng/100 ml. During low Na intake, the same dose of [des-Asp]-A II increased mean blood pressure from 83.7±3 to 86.7±3 mm Hg and plasma aldosterone concentration from 34.4±6.0 to 51.0±8.2 ng/100 ml. In contrast, A II from 2 to 6 pmol/kg per min during normal Na intake increased mean blood pressure from 83.3±4 to 102.3±4 mm Hg and plasma aldosterone concentration from 7.0±2.2 to 26.8±2.0 ng/100 ml; during low Na intake, A II increased mean blood pressure from 83.0±3 to 96.0±4 mm Hg and plasma aldosterone concentration from 42.0±9.7 to 102.2±15.4 ng/100 ml. A II and [des-Asp]-A II were equally effective in suppressing renin release. Plasma cortisol and Na and K concentration did not change.

Authors

Robert M. Carey, E. Darracott Vaughan Jr., Michael J. Peach, Carlos R. Ayers