The Effect of Insulin on the Rise in Blood Pressure and Plasma Aldosterone after Angiotensin II in Normal Man

1. The effect of an intravenous infusion of insulin [2.5 units h⁻¹ (m² of body surface area)⁻¹] on the rise in blood pressure and plasma aldosterone after intravenous angiotensin II (5, 10, and 20 ng min⁻¹ kg⁻¹) was investigated in six healthy, sodium-loaded men.

2. Serum insulin reached 96.8 ± 18.1 μ-units/ml (control: 7.0 ± 1.5 μ-units/ml) and serum potassium fell from 4.2 ± 0.2 mmol/l to 3.6 ± 0.2 mmol/l (P < 0.005).

3. Hyperinsulinaemia increased (P < 0.05) the secretion of aldosterone during the largest dose of angiotensin II (20 ng min⁻¹ kg⁻¹), but had no effect on the rise in blood pressure after angiotensin II.