EFFECT OF METOCLOPRAMIDE, A DOPAMINERGIC INHIBITOR, ON RENIN AND ALDOSTERONE IN IDIOPATHIC EDEMA - POSSIBLE THERAPEUTIC APPROACH WITH LEVODOPA AND CARBIDOPA

Metoclopramide, a dopaminergic inhibitor, was injected (10 mg i.v.) in 15 normal women and 9 patients with clinical evidence of idiopathic edema, while on a 130 meq Na and 50-70 meq K diet. The subjects kept a recumbent position during the test. PRA [plasma renin activity] slightly increased at 45 min (P < 0.01) in normal women. A low Na diet (20-40 meq/day) seemed to accelerate the PRA response, which was significant at 20 min (P < 0.05). In patients with idiopathic edema, PRA consistently increased at 20, 30 and 45 min (P < 0.05). Plasma aldosterone (PA) increases significantly at 10, 20, 30, 45 and 60 min (P < 0.005) both in normal women and in patients. The absolute change of PA from 0-10 min was significantly higher in patients with idiopathic edema (P < 0.001) and preceded the increase of PRA. In 5 normal women, urinary Na decreased and urinary K increased after metoclopramide. Serum electrolytes were not modified. In 2 patients with idiopathic edema and hypokalemia, the treatment with a central dopaminergic agonist (250 mg levodopa and 100 mg carbidopa) reduced PRA and PA, restored serum K to normal values, and increased urinary excretion of Na. These data suggest a dopaminergic control of renin and aldosterone and an alteration of this control in idiopathic edema.