Effect Of Dexmedetomidine On The Expression Of High Mobility Group Box 1 In The Lung Tissue In Septic Rats

ObjectiveTo investigate the effect of dexmedetomidine on expression of high mobility group box 1(HMGB1) protein m RNA in lung of septic rats; to explore the mechanism of dexmedetomidine on reducing acute lung injury, which may provide a theoretical basis of dexmedetomidine used for the clinical treatment of sepsis.MethodsForty-five male Sprague Dawley rats weighing 250-300 g were randomly divided into 3 groups(n=15):Sham operation group(Group SHAM) 、Sepsis group(Group CLP) 、 Dexmedetomidine group(Group DEX). Each rat had cecal ligation and puncture surgery(CLP) to establish model of sepsis except those in Group SHAM.Group DEX was given intraperitoneally dexmedetomidine in a dose of 40μg/kg at 1hour after CLP.Isometric normal saline was given intraperitoneally in Group SHAM and Group CLP.The lung tissues were taken at 6、24 and 48 hour after CLP. The expression of the HMGB1 m RNA were examined by RT-PCR and the level of HMGB1 protein in the lungs were detected by Western blot. The acute lung injury was detected by HE stain.Results1. Group SHAM had very weakly expression of HMGB1 m RNA and HMGB1 on lung tissue at all time points,and no statistics significance were observed.2. The expression of HMGB1 m RNA and HMGB1 on lung tissue of Group CLP、DEX at all time points were obviously higher than Group SHAM(P<0.05).3. The expression of HMGB1 m RNA and HMGB1 on lung tissue of Group DEX at all time points were obviously lower than Group CLP(P<0.05).4. The injury of pathology of lung was slighter in Group Dex than in Group CLP.ConclusionDexmedetomidine can reduce lung injury through inhibiting HMGB1 expression in septic rats.