[The changes of intraerythrocyte calcium metabolism and their responses to nifedipine in patients with essential hypertension].

The erythrocytic activity membrane ATPases, intraerythrocytic calcium concentration ([Ca2+]i), plasma renin activity (PRA), and angiotensin II (AT-II) in 18 essential hypertensive patients (EH) and matched normal controls were determined. In the EH group, Na(+)-K(+)-ATPase, Ca(2+)-ATPase, PRA were much lower than those in the controls, and [Ca2+]i, AT-II were higher. When blood pressure was become normotensive after a course of taking nifedipine therapy, the forementioned parameter alteration restored to approach the normal range, the changes were significnt. [Ca2+]i was positively correlated with MAP, and negatively correlated with PRA and AT-II. The results suggest that the increase erythrocytic membrane ATPase activity and decrease in renin-angiotensin system activity in nifedipine treatment may be another important antihypertensive mechanism besides accompanied with the rectifying of abnormal cellular calcium metabolism.