The aim of our study was to find out whether dexrazoxane (DEX) treatment reduces myocardial infarct size and arrhythmias induced by regional I/R in open-chest rats and in isolated perfused hearts, and to find out its most effective dose. Our results showed that DEX in the single dose of 150 mg.kg-1 effectively suppressed ventricular arrhythmias in isolated hearts subjected to acute I/R, but it was insufficient to reduce arrhythmias in open-chest animals, and only the highest dose of DEX (450 mg.kg-1) decreased myocardial infarct size.
The protective effects of DEX were not accompanied by decreases of oxidative stress markers in the myocardium, suggesting that other protective mechanism(s) than limitation of ROS formation might play a role.