The inability of Angiotensin II infusions to raise plasma vasopressin levels in haemodialysis patients

Abstract

Since it has previously been claimed that angiotensin II (AII) stimulates vasopressin (AVP) secretion, the effect of AII-infusions was studied in 6 normal, 5 non-nephrectomized hemodialysis (HD) patients, and 6 nephrectomized HD patients. In dialysis patients the infusion rate was increased step-wise from 2-12 ng AII/kg body wt .times. min-1 and was terminated if diastolic blood pressure (BP) increased more than 20 mmHg. Normals were infused at a constant rate of 4 ng AII/kg body wt .times. min-1. In all the groups significant increments in BP and plasma aldosterone occurred while plasma renin activity decreased. The plasma vasopressin level was unchanged in normals, while in the 2 groups of dialysis patients a minor decrease was found. The present study has not been able to confirm a stimulating effect of a physiological dose of AII on AVP secretion, and the results in anephric patients indicate that a normal plasma AII concentration is of no importance for the plasma AVP level.