Publication de 4 numéros par an
ISSN Imprimer: 2155-014X
ISSN En ligne: 2155-0158
Hypoxic Preconditioning Prevents Induction and Activation of 5-Lipoxygenase during Ischemia and Reperfusion of Rat Heart
RÉSUMÉ
Male Wistar rats were subjected to hypoxic preconditioning (10% O2 in nitrogen for 3 hours). In 24 hours, the heart was isolated and subjected to ischemia (30 min) and reperfusion (40 min) using Langendorf method. Changes in 5-lipoxygenase (5-LO) protein expression were evaluated in the heart ventricles and myocardial subcellular fractions following preconditioning, in dynamics of ischemia and reperfusion. It has been found that hypoxic preconditioning reduces necrotic damage to cardiomyocytes in post-ischemic reperfusion by reducing the release of lactate dehydrogenase into perfusate by 27.6%. After ischemia/reperfusion, 5-LO expression increases as much as 10.5 times in the left ventricle and 14.3-fold in the right one. During ischemia and post-ischemic reperfusion there is a gradual translocation of 5-LO protein in the nuclear subcellular compartment, more pronounced in the left ventricle. Hypoxic precon-ditioning does not result in a significant increase in 5-LO expression, completely preventing its growth in the subsequent ischemia-reperfusion. It, in part, reduces protein translocation during reperfusion in the left ventricle. Thus, hypoxic preconditioning limits pro-inflammatory effects of ischemia/reperfusion in the myocardium by preventing an increase in 5-LO expression and reducing cardiomyocyte alteration.