Dopaminergic regulation of plasma aldosterone secretion in hypertensive patients
Kuo, Y.M.; Wu, K.D.; Hsieh, B.S.; Chen, W.Y.; Yen, T.S.; Tsai, T.J.
Journal of the Formosan Medical Association 84(11): 1222-1232
1985
ISSN/ISBN: 0371-7682 PMID: 3868697 Document Number: 244742
This study was designed to investigate the effects of metoclopramide, a dopamine antagonist, on aldosterone production in the hypertensive patients. In addition, we examined the effect of various clinical and biochemical factors, including sex, age, serum potassium level and plasma renin activity, on the response of plasma aldosterone to metoclopramide. Metoclopramide, 10 mg, was given by IV injection to 18 hypertensive patients. The basal level of plasma aldosterone was 11.64 .+-. 2.47 ng/dl (Mean .+-. SEM). Metoclopramide induced a sharp increase of plasma aldosterone. Plasma aldosterone increased to 16.33 .+-. 3.46 ng/dl at 5 minutes and (reached to peak) 24.19 .+-. 4.91 ng/dl at 15 minutes after metoclopramide injection. The mean incremental percentage changes in aldosterone level were 77.89 .+-. 25.39% at 5 minutes and 128.56 .+-. 36.18% at 15 minutes, both attained significance when compared with the baseline value (P < 0.001). The response of plasma aldosterone to metoclopramide in the female group was greater than that in the male group (P < 0.025), and it was greater in the hypokalemic group than that in the normokalemic group (P < 0.025). There was no significant difference in plasma aldosterone response among patients with different age or plasma renin activity. These results indicate that the plasma aldosterone production is under inhibitory control by dopaminergic system in hypertensive patients. This inhibition is more evident in female patients and in patients with low serum potassium level.