[Raised plasma-prolactin levels in essential hypertension: index of reduced hypothalamic dopaminergic activity (author's transl)].

Serial measurements of plasma-prolactin concentration (HPr) and plasma-renin activity (PRA) at 30-min intervals were made in 19 male patients with essential hypertension and in 8 normotensive subjects. HPr was markedly higher in the hypertensive patients than in the normotensive controls. Patients with reduced plasma-renin activity and only slightly elevated HPr-levels showed lower urinary sodium excretion, but a more pronouced 24-h natriuretic response to i.v. furosemide than patients with normal renin and very high HPr-levels. Six patients were treated with the dopaminergic agonist bromocriptine. The drug induced a significant blood pressure reduction in five patients and normalised pressure in two patients. The data do not indicate a role for prolactin in sustaining hypertension via renal salt retaining mechanisms. It is suggested that the raised HPr-levels represent an index of altered central nervous function, characterized by reduced hypothalamic activity. The blood pressure-lowering effect of the dopaminergic agonist bromocriptine fits with the hypothesis that reduced hypothalamic dopaminergic activity might be a factor in the pathogenesis of essential hypertension.