Urinary dopamine excretion in normotensive subjects with or without family history of hypertension.

To define the role of the renal dopaminergic system in the pathogenesis of essential hypertension, urinary free dopamine excretion was examined in 23 normotensive subjects who had one or more first-degree relatives with essential hypertension, and also in 36 matched control subjects without any such family history. The group urinary dopamine excretion and urinary sodium excretion were not different. However, a significant urine dopamine-sodium relationship was apparent in the controls but not in the relatives due to relatively high dopamine output in those with lower sodium excretion. The two groups were similar as regards blood pressure (BP), plasma renin activity (PRA), prolactin and catecholamines. These findings demonstrate an alteration in the urine dopamine-sodium relationship in some normotensive subjects with genetic risk of hypertension.