Postexercise reflex control of forearm vascular resistance during calcium antagonism with slow-release oral isradipine.

In untreated hypertensive patients, blood pressure is decreased during the hours that follow a single bout of exercise, but the mechanisms involved are as yet unknown. As antihypertensive chemotherapy may interfere with cardiovascular regulation, we investigated the effects of calcium antagonism with isradipine (slow-release oral formulation, SRO) on postexercise blood pressure and on the reflex control of forearm vascular resistance in patients with mild-to-moderate hypertension. The results show that isradipine SRO exerted an additional blood pressure-lowering effect after exercise that was associated with a further decrease in forearm vascular resistance. The reflex changes in forearm vascular resistance were potentiated after exercise, but were not further affected by isradipine SRO. Therefore, isradipine SRO does not interfere with the cardiovascular mechanisms that act to decrease blood pressure after exercise in patients who have hypertension.