Effects of sevoflurane preconditioning on lung injury induced by renal ischemia-reperfusion in rats

Objective To evaluate the effects of sevoflurane preconditioning on lung injury induced by renal ischemia-reperfusion (I/R) in rats.Methods Forty adult male Wistar rats,aged 3 months,weighing 200-250 g,were randomly divided into 5 groups (n =8 each):sham operation group (group S); renal I/R group (group I/R); 1.1％ sevoflurane preconditioning group (group SP1); 2.2％ sevoflurane preconditioning group (group SP2); and 3.3％ sevoflurane preconditioning group (group SP3).Renal I/R was induced by clamping bilateral renal pedicles for 45 min followed by 6 h reperfusion.In SP1-SP3 groups,1.1％,2.2％ and 3.3％ sevoflurane were inhaled for 1 h,respectively,before ischemia,followed by 10 min washout.The rats were sacrificed by exsanguination at 6 h of reperfusion,and lungs were removed for determination of wet/dry lung weight (W/D) ratio,myeloperoxidase (MPO) activity and expression of angiotensin converting enzyme (ACE) mRNA,and for microscope examination of pathologic changes which were scored.Results Compared with group S,the pathological score,W/D ratio,MPO activity and expression of ACE mRNA were significantly increased in I/R and SP1-SP3 groups (P ＜ 0.05).Compared with group I/R,the pathological score,W/D ratio,MPO activity and expression of ACE mRNA were significantly decreased in SP1-SP3 groups (P ＜ 0.05).Compared with SP1 and SP3 groups,the pathological score,W/D ratio,MPO activity and expression of ACE mRNA were significantly decreased in group SP2 (P ＜ 0.05).Compared with group SP1,the W/D ratio was significantly decreased (P ＜0.05),and no significant changes were found in the other parameters in group SP3 (P ＞ 0.05).Conclusion Sevoflurane preconditioning can attenuate lung injury induced by renal I/R and inhibition of ACE synthesis is involved in the mechanism. Key words: Anesthetics, inhalation ;  Ischemic preconditioning ;  Respiratory distress syndrome, adult; Kidney;  Reperfusion injury