EFFECT OF MANIDIPINE CHLORIDE ON VARIOUS ASPECTS OF ENDOCRINE FUNCTION, INCLUDING PLASMA-LEVELS OF ENDOTHELIN-1 AND HUMAN ATRIAL-NATRIURETIC-PEPTIDE, IN PATIENTS WITH ESSENTIAL-HYPERTENSION

We assessed various aspects of endocrine function in patients treated for essential hypertension with manidipine chloride, a calcium channel blocker, to study the effects of this drug on several endogenous humo ral factors, including human atrial natriuretic peptide (hANP) and end othelin-1 (ET), which influence vasoconstriction and blood fluid volum e. The study included 19 patients with essential hypertension. All pat ients received manidipine chloride 10 mg/d for 24 weeks. After treatme nt blood pressure was normalized in all patients, and there were no si gnificant changes in plasma renin activity or blood concentrations of vasopressin, hANP, ET, aldosterone, adrenaline, or noradrenaline. Ther e was a statistically significant negative correlation between the cha nge in ET levels and hANP levels before and after treatment. We also o bserved a statistically significant negative correlation between the c hange in systolic blood pressure caused by manidipine chloride and the change in hANP levels before and after treatment. These findings sugg est that hANP and ET levels are systematically changed by manidipine c hloride in patients with essential hypertension. We also speculate tha t changes in blood pressure may be closely related to levels of hANP i n patients treated with manidipine chloride.