Sex might be an important factor in the development of certain ischemic diseases of the heart. We tried to assess the effects of treating rats with estradiol or testosterone on the develop­ment of myocardial damage caused by ischemia/reperfusion. Experiments were carried out on the isolated hearts of sexually mature rats of both sexes (230–330 g) which were perfused with aerated Krebs-Henseleit solution for 30 minutes and then subjected to 40 minutes zero-flow ischemia followed by 55 minutes of reperfusion.

The severity of myocardial damage was assessed based on postischemic changes in the following registered parameters: coronary blood flow, lactate dehydrogenase release rate, left ventricular pressure, heart rate and duration of ventricular fibrillation during reperfusion.