[Hypoxic preconditioning prevents the induction and activation of 5-lipoxygenase during ischemia and reperfusion of rat heart].

Abstract Male Wistar rats were subjected to hypoxic preconditioning (10% O2 in nitrogen for 3 h). In 24 h heart were isolated and subjected to 30 min ischemia and 40 min reperfusion. Changes in expression of 5-lipoxygenase (5-LO) protein in rat heart ventricles, and in myocardial subcellular fractions were evaluated by Western blotting. It was found that hypoxic preconditioning attenuated reperfusion damage of cardiomyocytes with reducing the release of LDH by 27.6%. After ischemia and reperfusion, expression of 5-LO was 10.5-fold elevated in the left ventricle and 14.3-fold - in the right one. During ischemia and reperfusion occurred gradual translocation of 5-LO protein in nuclear subcellular compartment, more expressive in the left ventricle. Hypoxic preconditioning did not significant increase in 5-LO expression, but fully prevented its growth in the following ischemia-reperfusion, and partly reduced protein translocation at reperfusion in the left ventricle. Thus, hypoxic preconditioning limits proinflammatory effects ofischemia and reperfusion in myocardium, preventing the increase in expression of 5-LO, and reducing the alteration of cardiomyocytes.