Dexmedetomidine On Renal Ischemia/Reperfusion The Distant Organs Lung Injury Protection Role

Objective：To discuss the protective effect and mechanism of dexmedetomidine onremote lung injury induced by renal ischemia-reperfusion though rat model.Methods：Adult male rats, about250-300g, were randomized to four groups：control groups (S)；renal ischemia-reperfusion(R)；injection of dexmedetomidinebefore ischemia(pre-Dex) and after reperfusion(post-Dex). Rats in Group S haddissection but with no occlusion of the renal vessel. Group R was induced bynephrectomy on the left side kidney and ischemia for45minutes on the right. Rats inGroup pre-Dex were injected dexmedetomidine1μg/kg more than10min beforeischemia on the Left kidney, then changed to0.5μg/kg until ischemia occurred. Rats inGroup post-Dex were injected dexmedetomidine immediately after reperfusion occurred.At the end of6hrs reperfusion collected the blood and BALF in each group to compareCr, IL-1β and TNF-α， Pulmonary wet/dry ratio and histopathological evaluation.Results：Copared with group S，Group R，pre-Dex and post-Dex，Content of Crin blood was increased (P<0.05), decreased in Group pre-Dex and post-Dex(P<0.05)，when compared respectively with that in Group S.Copared with group S，Group R，pre-Dex and post-Dex，Content of IL-1andTNF-α in BALF was increased in Group R (P<0.05), decreased in Group pre-Dex andpost-Dex(P<0.05),when compared respectively with that in Group SCopared with group S，Group R，pre-Dex and post-Dex，The lung wet/dry ratiowas increased in (P<0.05), decreased in Group pre-Dex(P<0.05) andpost-Dex(P<0.05),when compared respectively with that in Group S.Compared with Group S, Group R featured with alveolar epithelial cell hyperplasia,increased interstitial cellularity, alveolar space narrow even disappearance,angiotelectasis in alveolar wall, and inflammatory cells infiltration. Group pre-Dex andGroup post-Dex were featured with obvious mild lung injury. Copared with group S，Group R，pre-Dex and post-Dex，Content of IL-1, TNf-αin blood was increased (P<0.05), decreased in Group pre-Dex and post-Dex(P<0.05)，when compared respectively with that in Group S.Conclusion：1.Renal ischemia-reperfusion can induce remote lung injury2．Dexmedetomidine can attenuate lung injury induced by renal ischemia–reperfusion, which is regarded with its suppression of the release and over-expressionof cell factors.