Dopaminergic inhibition of aldosterone secretion in man is independent of the autonomic nervous system.

To determine whether the plasma aldosterone response to metoclopramide, a dopamine antagonist, is mediated by the autonomic nervous system in man, five healthy male volunteers were injected with metoclopramide during an infusion of either 5% dextrose in water or trimethaphan, a ganglionic blocker. Despite evidence of ganglionic blockade during the trimethaphan infusion, the aldosterone response to metoclopramide remained intact. This suggests that the aldosterone response to metoclopramide is not mediated by the autonomic nervous system in man as it appears to be in the sheep, and suggests species variation in the mechanism of this this mineralocorticoid response.