Effects of Intracerebroventricular Administration of Magnesium Sulphate on Blood Pressure and Heart Rate in Anesthetized Normotensive and Hypertensive Rats

Abstract

Intracerebrove ntricuIar (i.c.v.) injection of magnesium sulphate (MgSO₄: 2.5, 5 and 10 μmol in 5 μl) decreased blood pressure and heart rate in both anesthetized normotensive (WKY) and hypertensive rats (SHR). The effects were greater in WKY than in SHR. Moreover, a pretreatment with hexamethonium (2 mg/kg, i.v.) significantly blunted the hypotensive and bradycardic effects induced by i.c.v. injection of 10 μmol of MgSO₄ in both WKY and SHR. Our data suggest that MgSO₄ produces hypotensive and bradycardic effects when injected i.c.v. in both WKY and SHR.