Increased sympathetic activity in renovascular hypertension in man.

1. Concentrations in venous plasma of adrenaline, noradrenaline and dopamine were measured in samples collected simultaneously from three different sites in three varieties of hypertension. 2. In adrenal venous plasma, levels of catecholamines were increased in renovascular hypertension (n = 8) and decreased in primary aldosteronism (n = 8) when compared with essential hypertension (n = 9). 3. Concentrations were similar in antecubital and low inferior vena caval plasma, where noradrenaline was higher in renovascular hypertension. 4. Altered adrenal venous in renovascular hypertension and in primary aldosteronism. 5. Adrenal venous catecholamines deserve further study as an index of sympathetic activity.