| Abstract: | A study was made of the effect of ethacizine, a new antiarrhythmic phenothiazint derivative, on the size of experimental myocardial infarction in rabbits 7 days after ligation of the coronary artery. Ethmozine was used as reference. Ethacizine diminished the extent of necrosis by 22.8% (P less than 0.05) when injected intravenously in divided doses beginning from the 30th minute of 2-hour ligation, the total dose being 1.5 mg/kg. The six-day cycle of ethacizine treatment instituted 24 h after coronary artery ligation (daily dose 1.2 mg/kg) provoked a more considerable reduction of the myocardial infarction size (by 44.9%). The effect of ethmozine was less pronounced though statistically significant. Ethacizine increased ATP content in both the ischemic and "intact" myocardium and minimized the impairment of membrane permeability in the occlusion zone 3 h after ligation when injected according to the first above-described scheme. It is assumed that these effects may contribute to the drug protective action on the ischemic myocardium. |
