Expression of HIF-1α and HIF-3α differentially changed in rat heart ventricles after hypoxic preconditioning

Transcription factors involved in the late myocardial preconditioning, induced by whole body hypoxia, were studied in adult male Wistar rats. In 24 h after the preconditioning we found HIF-1 alpha and HIF-3 alpha mRNA expression strongly elevated in the left ventricles without HIF-1 protein stabilization. Right ventricles demonstrated significant increase only HIF-3 alpha. mRNA expression. Initial HIF-3 alpha mRNA expression in both ventricles was 9.0-fold higher than HIF-1 alpha expression; in the right ventricles expression values were 4.0-8.0-fold higher, than in left ones. Thus, the right ventricles may have higher oxygen sensitivity and gene transcription ability that is accompanied with more significant delayed cardioprotection from infarction than in left ventricles. HIF-3a seems to be more strongly involved in hypoxic preconditioning than HIF-1 alpha.