Factors affecting the release and excretion of dopamine in the rat

The effects of inorganic salts and of diuretic agents on the excretion of dopamine (DA) were examined in the rat. Both types of treatment evoked significant increases in urinary DA excretion, urine volume and urinary sodium excretion. In the salt-treated animals a significant correlation was observed between DA excretion and urine volume, whereas after diuretic treatment there was better correlation between DA and urinary sodium excretion. The salt-treated animals showed a high correlation between administered chloride and DA excretion. Subcutaneous administration of DA produced a significant diuresis and an increase in sodium excretion. The mechanisms responsible for these responses are discussed with reference to the possibility that DA has a physiological role in the kidney.