The attenuation of myocardial susceptibility to ischemia/reperfusion injury by ischemic postconditioning in hypercholesteremia rats and the role of hypoxia inducible factor-1alpha / 中国应用生理学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore whether ischemic postconditioning can attenuate the myocardial injury induced by ischemia/reperfusion (I/R) in hypercholesteremic rats and whether hypoxia inducible factor-1alpha (HIF-1alpha) play a role in the protection.</p><p><b>METHODS</b>Adult male Wistar rats received a high fat diet for 8 weeks to prepare the hypercholesteremic models. Myocardial damage induced by ischemia/reperfusion was evaluated by infarct size, creatine kinase (CK) activity and myocardial apoptosis. HIF-1alpha mRNA level was detected by real time-RT-PCR and the protein level was detected by Western blot.</p><p><b>RESULTS</b>Myocardial infarct size, CK activity, and caspase-3 activity induced by I/R were markedly increased in hypercholesteremic rats compared with those in normal rats. Ischemic postconditioning attenuated the myocardial injury in both normal rats and hypercholesteremic rats, and increased HIF-1alpha protein level. There was a significant linear inverse relationship between HIF-1alpha protein level and infarct size (r = -0.802, P <0.01).</p><p><b>CONCLUSION</b>Hypercholesteremia enhanced the susceptibility of myocardia to ischemia/reperfusion injury. While ischemic postconditioning markedly attenuated the increase of myocardial susceptibility to I/R induced by hypercholesteremia. HIF-1alpha might be one of the mechanisms of protection by ischemic postconditioning.</p>