Effects of late postconditioning on gene expression and cell death in neonatal rat cardiomyocyte cultures

Abstract

The cell death and gene expression in neonatal cardiomyocyte cultures were investigated in a late postconditioning model. The primary cultures were subjected to a 30 min of anoxia followed by 60 min or 24 h of reoxygenation. Postconditioning was carried out in three cycles of 1 min reoxygenations followed by 1 min anoxia, respectively. After 24 h of reperfusion the percentages of living, necrotic, and apoptotic cells were determined by staining with bis-benzimide and propidium iodide. Anoxia–reoxygenation significantly increased the necrotic and apoptotic cells both at its first and second episodes. Postconditioning in remote period did not protect the cells from the second anoxia. Postconditioning decreased the anoxia–reoxygenation-induced increase of HSP70 and HSP90 mRNA expression. We observed a decrease of HIF-3alpha gene expression in remote postconditioning. The FRAP gene expression was leveled to control value. Thus, the changes of mRNA gene expression did not show cytoprotection of cardiomyocytes in remote postconditioning model.