The effect of indomethacin on plasma renin activity in man under normal conditions and after stimulation of the renin angiotensin system.

1) The influence of oral indomethacin on basal and stimulated plasma renin activity in normal human subjects was determined. 2) Indomethacin lowers the basal plasma renin activity in man. 3) The response of the plasma renin activity after indomethacin to physiological and pharmacological stimuli is maintained at a lower level. 4) There is no evidence from our experiments that major changes in the sodium balance are responsible for the effects observed.