Central dopaminergic control of prolactin in essential hypertension.

An exaggerated, early prolactin response (p less than 0.01) was observed in ten patients with untreated essential hypertension (148 +/- 4/97 +/- 1 mmHg, means +/- SE) compared with ten healthy normotensive men of the same age (124 +/- 3/78 +/- 2 mmHg) after administration of metoclopramide, a competitive dopamine antagonist. The normotensive peak value of prolactin never exceeded that of the hypertensive (p less than 0.05). Since prolactin is considered an indicator of central dopaminergic activity, these findings suggest an altered central dopaminergic activity in mild essential hypertension.