Effect of Methyldopa on Plasma Renin Activity in Man
The effect of methyldopa on plasma renin activity was studied in one hypertensive and four normotensive human volunteers. Peripheral venous blood for the estimation of plasma renin activity was obtained with the subjects supine and in a 70° head-up tilted position before, during and, in two subjects, after treatment with oral methyldopa. Despite a reduction in mean arterial pressure, the plasma renin activity was decreased by methyldopa in each subject. The increase in plasma renin activity associated with tilting, however, was not significantly suppressed by methyldopa. These results indicate that treatment with methyldopa can simultaneously decrease mean arterial pressure and plasma renin activity and it is possible that these effects may be causally related.
Dr. Gaffney is the recipient of a Research Career Development Award from the National Institutes of Health, U.S.Public Health Service.
- Received June 27, 1969.
- Accepted September 13, 1969.
- © 1969 American Heart Association, Inc.