RESUMEN
[ ABSTRACT] AIM:To explore the effect of dexmedetomidine ( DEX) on the CCAAT/enhancer-binding protein-homologous protein ( CHOP) pathway during lung ischemia-reperfusion ( I/R) in mice.METHODS:C57BL/6J male mice were randomly divided into sham operation group ( sham group) , lung ischemia/reperfusion group ( I/R group) , ischemia/reperfusion +normal saline group ( I/R+NS group ) and ischemia/reperfusion+dexmedetomidine group ( I/R+DEX group) .Dexmedetomidine was infused intraperitoneally with 25 μg/kg for 30 min prior to the ischemia period in I/R+DEX group, the normal saline was administrated with the same volume of dexmedetomidine in I/R+NS group.After fini-shed the 3 h-reperfusion period , the left lung tissues were harvested to determine lung wet/dry weight ( W/D) , the total lung water content ( TLW) , and index of quantitative evaluation for alveolar damage ( IQA) .Morphological observation and terminal-deoxynucleotidyl transferase mediated nick end labeling ( TUNEL) were applied to evaluate the structure changes and the apoptosis index (AI) of the lung tissues.The expression of CHOP and glucose-regulated protein 78 (GRP78) at mRNA and protein levels in the lung tissues was detected by Western blot and RT-PCR.RESULTS:Compared with sham group, the W/D, TLW, IQA, AI, the mRNA and protein expression of CHOP and GRP78 obviously increased, and the left lung tissues structure were damaged more obviously both in I/R group and I/R+NS group.Compared with I/R group, the W/D, TLW, IQA, AI and the protein and mRNA expression of CHOP in I/R+DEX group decreased, the injury of the left lung tissue structures induced by I/R in I/R+DEX group were also alleviated .CONCLUSION:DEX alleviates the lung I/R injury, which may be related to inhibition of apoptosis mediated by CHOP pathway.