Superoxide production during ischemia-reperfusion in the perfused rat heart: A comparison of two methods of measurement

► Oxidized dihydroethidine performs as membrane potential probe in myocardium. ► Transmembrane traffic disturbs 2-OH-ethidium monitoring of myocardial superoxide. ► Lucigenin chemiluminescence agrees with postischemic Q-cycle switch in the heart. ► No superoxide production during global myocardial ischemia/anoxia