The effect of desferal on rat heart mitochondrial function, iron content, and xanthine dehydrogenase/oxidase conversion during ischemia-reperfusion

Cardiac mitochondrial function as measured by oxidative phosphorylation is impaired by ischemia; and, this deteriorates even further on reperfusion of the heart. Free oxygen radicals, especially the formation of hydroxyl radicals via the iron-catalyzed Haber-Weiss and Fenton reactions, have been implicated in the reperfusion injury. In this study, the effect of desferrioxamine (desferal) in the perfusate on mitochondrial function of isolated rat hearts during different periods of normothermic ischemic cardiac arrest (NICA), and subsequent reperfusion was investigated. Mitochondrial functions measured were the QO 2 (state 3); ADP/O ratio and oxidative phosphorylation; the mitochondrial, loosely bound (chelateable) iron (LB-iron); the xanthine dehydrogenase and xanthine oxidase activities. Inclusion of desferal in the perfusion solution significantly improved mitochondrial function during the different NICA periods, and prevented the deterioration of mitochondrial function resulting from reperfusion. Desferal did not significantly affect the LB-iron content of the mitochondria or the ratio of xanthine dehydrogenase/xanthine oxidase activities in the mitochondria during NICA or reperfusion. Our experiments suggest that iron, which is free to be chelated by desferal, plays a role in this injury to the rat myocardium.