Enhanced adrenal responsiveness to angiotensin II in patients with low renin essential hypertension.

The plasma aldosterone response to infused angiotensin II was determined in normal controls and in patients with normal renin and with low renin essential hypertension. The patients with low renin essential hypertension showed an enhanced plasma aldosterone response when compared to the other two groups. This finding may explain why plasma aldosterone levels remain within normal limits in the face of suppressed plasma renin and angiotensin II concentrations in low renin essential hypertension.

Postural hypotension: adrenergic responsivity and levodopa therapy.

Four subjects with orthostatic hypotension were given intravenous infusions of methoxamine and isoproterenol. Methoxamine caused an elevation in systolic blood pressure. Isoproterenol resulted in a fall in blood pressure in three of the subjects.