Effect of dexmedetomidine on PERK signaling pathway in cardiomyocytes of rats with severe scald / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of dexmedetomidine on protein kinase RNA-like endoplasmic reticulum kinase (PERK) signaling pathway in cardiomyocytes of the rats with severe scald.Methods Twenty-four healthy adult male Sprague-Dawley rats,weighing 220-280 g,were randomly divided into 3 groups (n =8 each) using a random number tablecontrol group (group C),severe scald group (group S),and scald + dexmedetomidine group (group D).Thirty percent of the total body surface area was shaved on the back and then exposed to 94 ℃ water for 12 s to establish the model of 3rd degree scald.Dexmedetomidine 30 μg/kg (2 μg/ml) was intraperitoneally injected immediately after scald in group D.Myocardial specimens were obtained at 12 h after scald for examination of the pathological changes and for determination of cell apoptosis and expression of C/EBP-homologous protein (CHOP),PERK,and phosphorylated PERK (p-PERK) by Western blot.The apoptosis index and p-PERK/PERK ratio were calculated.Results Compared with group C,the apoptosis index was significantly increased,the expression of CHOP,PERK and p-PERK was significantly up-regulated,and the p-PERK/PERK ratio was significantly increased in S and D groups (P＜0.05).Compared with group S,the apoptosis index was significantly decreased,the expression of CHOP,PERK and p-PERK was significantly down-regulated,and the p-PERK/PERK ratio was significantly decreased (P＜0.05),and the pathological changes of myocardium were significantly attenuated in group D.Conclusion The mechanism by which dexmedetomidine inhibits apoptosis in cardiomyocytes is related to inhibition of PERK signaling pathway in the rats with severe scald.