The Influence of Whole-body Hypoxic Preconditioning on Cytochrome C Expression and Apoptoss in Rats with Ischemia/Peperfusion Caused Lung Injury

Objective:To investigate the protective effect of whole-body hypoxic preconditioning (HPC) on ischemia/reperfusion(lung-I/R)caused lung injury in rats. Methods: HPC model rat was established with repetitive sublethal hypoxia for 5 times,while lung-I/R rat was prepared with left lung hilar clamping for 45 min followed by 180-min reperfusion. Thirty rats were randomly divided into 3 groups (n=10,respectively): sham-operation group (group S),lung-I/R group (group I/R) and HPC+lung-I/R group (group H). After the experiment,lung weights were measured and wet/dry ratioes were calculated,lung morphological changes were observed on HE stained sections,expression of cytochrome C was detected with immunohistochemitry method,and cell apoptosis was assessed with TUNEL method. Result: Compared with those in group S,pathological changes of lung tissue were more obvious,and wet/dry ratio,cytochrome C expression,and cell apoptosis index were significantly increased(P0.05)in group I/R;While in group H,lung tissue pathological chages were milder,and the other indexes were markedly lowered than those in group I/R. Conclusion: Whole-body hypoxic preconditioning in rats can protect lung from I/R caused injury by reducing release of cytochrome C and inhibiting cell apoptosis.