Suppression of plasma endothelin-1 level by alpha-human atrial natriuretic peptide and angiotensin converting enzyme inhibition in normal men.

The effect of synthetic alpha-human atrial natriuretic peptide (alpha-hANP) on plasma endothelin-1 (ET-1) level was examined in 6 healthy subjects. Intravenous infusion of alpha-ANP (0.1 micrograms/kg/min) resulted in significant falls in plasma renin activity and aldosterone, but without effect on ET-1 level. An angiotensin converting enzyme inhibitor, captopril, increased plasma renin activity and decreased aldosterone, respectively. However, plasma ET-1 levels were not modified by captopril. In cases with alpha-hANP infusion after captopril (25 mg, p.o.,), the renin-angiotensin-aldosterone system was further inhibited compared with the first group, and ET-1 at 60 min was significantly suppressed from the baseline. These data suggest that alpha-hANP when combined with captopril brings about the suppression of plasma ET-1 concentrations in men.