Adrenal Medullary Hormones in Water Diuresis.

Summary The injection of non-epinephrine in the rat is more effective in causing an augmentation of water diuresis than is adrenalin. Pure 1-epinephrine has no stimulating action on diuresis. Dibenamine causes a water retention in intact rats but fails to do so in adrenal medullectomized rats. Dibenamine blocks and reverses the diuretic activity of adrenalin in intact rats but it less effectively blocks such activity of norepinephrine. Dibenamine, in the dosage used, was incapable of blocking the action of norepinephrine in medullectomized animals. These results indicate that the diuretic action of adrenal medullary hormone is not due to epinephrine but to the presence of norepinephrine.