Reduction of experimental myocardial infarct size by pre-treatment with magnesium sulfate in rats.

Experimental myocardial infarction was induced in albino rats by administration of isoprenaline hydrochloride, 85 mg/kg, sc, daily for two consecutive days. Such rats were pretreated with either saline or magnesium sulfate (60 mg/kg) po, daily for three weeks, to serve as control or treated groups respectively. Heart specimens were taken for gross and histological examination at 24 hr, on 5th day, 12th day and 21st day. Infarct size was significantly reduced in the magnesium-treated group (P less than 0.05). We conclude that magnesium sulfate exerted a potent prophylactic effect in limiting infarct size in rats.