RÉSUMÉ
Objective To investigate the effect of sevoflurane preconditioning on lung injury induced by limb ischemia-reperfusion in rats and the relationship with endoplasmic reticulum stress.Methods Forty-five healthy male Sprague-Dawley rats,aged 6-8 weeks,weighing 250-300 g,were randomly allocated into 3 groups (n =15 each) using a random number table:sham operation group (group S),limb ischemia-reperfusion group (group LIR),and sevoflurane preconditioning group (group SP).Limb ischemia-reperfusion was induced by clamping bilateral femoral arteries for 3 h followed by 3 h reperfusion in LIR and SP groups.In group SP,2.5％ sevoflurane was inhaled for 30 min,and 15 min later the model was established.Before ischemia and at 3 h of reperfusion (at the corresponding time point in group S),arterial blood samples were collected for blood gas analysis,and arterial oxygen partial pressure (PaO2) and arterial carbon dioxide partial pressure (PaCO2) were recorded.The rats were sacrificed at 3 h of reperfusion,and lung specimens were obtained for determination of wet to dry lung weight ratio (W/D ratio) and total lung water content (TLW) and for microscopic examination of the pathological changes,and index of quantitative evaluation for alveolar damage (IQA) was calculated.The expression of glucose-regulated protein 78 (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP) protein and mRNA in lung tissues was detected by Western blot and real-time polymerase chain reaction,respectively.Results Compared to group S,the PaO2was significantly decreased at 3 h of reperfusion,the W/D ratio,TLW and IQA were significantly increased,the expression of GRP78 and CHOP protein and mRNA was significantly up-regulated (P＜0.05),and no significant change was found in PaCO2 in group LIR (P＞0.05).Compared to group LIR,the PaO2 was significantly increased at 3 h of reperfusion,the W/D ratio,TLW and IQA were significantly decreased,the expression of GRP78 and CHOP protein and mRNA was significantly down-regulated (P＜ 0.05),and no significant change was found in PaCO2 in group SP (P＞0.05).Conclusion Sevoflurane preconditioning can ameliorate lung injury induced by limb ischemia-reperfusion in the rats,and the mechanism is related to inhibition of endoplasmic reticulum stress.