The effect of initial lower PO_2 controlled reperfusion on cyanotic hypoxic immature myocardial protection / 中华胸心血管外科杂志

ABSTRACT

Objective: To explore the effect of initial lower PO_2 controlled reperfusion on cyanotic hypoxic immature myocardium protective during post-ischemia reperfusion. Methods: 24 hypoxic neonatal rabbits were randomized into 3 groups (8 in each group). Group I (initial lower PO_2 controlled reperfusion), group II (normal PO_2 controlled reperfusion), group III (high PO_2 reperfusion group). Using isolate heart Langendorff ischemia-reperfusion model, the myocardial protection results were observed and the mechanism were discussed from molecular biological and ultrastructural view. Results: Compared with high PO_2 reperfusion group and normal PO_2 reperfusion group, the products of oxygen free radical were lowered at the end of reperfusion in initial lower PO_2 controlled reperfusion group. ATP content was increased, myocardial contractility was elevated, coronary sinus flow was raised, the degree of myocardium edema was reduced, and ultrastructure alteration was lessened significantly. Conclusion: Initial lower PO_2 controlled reperfusion reduces oxygen free radical injury, enhances myocardial energy metabolism, lessens myocytic structure destruction and improves postischemic function recovery of cyanotic myocardium.