Effects of magnesium on changes in blood pressure and plasma aldosterone induced by angiotensin II

This study examined the effects of magnesium on changes in blood pressure and plasma aldosterone concentration (PAC) elicited by angiotensin II in rats. The infusion of angiotensin II (0.1 nmol/kg/min) for 30 min increased mean arterial pressure (MAP) and PAC. Simultaneous infusion of magnesium sulphate (5 mumols/kg/min) attenuated the MAP elevation (157.0 +/- 5.2 (SE) v 141.6 +/- 3.5 mm Hg, P less than .01) and the increase in PAC (447 +/- 70 v 233 +/- 50 pg/mL, P less than .01) brought about by angiotensin II. These effects of magnesium were abolished when endogenous angiotensin II was suppressed by the administration of captopril, an angiotensin converting enzyme inhibitor. The results suggest that magensium may attenuate the biological actions of angiotensin II.