氯胺酮对严重烧伤大鼠心肌HSP 70表达的影响

目的 评价氯胺酮对严重烧伤大鼠心肌HSP 70表达的影响,探讨其心肌保护的机制.方法 雄性Wistar大鼠72只,随机分为正常对照组(C组,n=8)、烧伤组(BI组,n=32)和氯胺酮组(K组,n=32).K组或BI组于烧伤模型制备成功后15 min分别肌肉注射氯胺酮20 mg/kg或等容量生理盐水,于给药后3、6、12和24 h分别随机处死8只大鼠,取心肌组织,采用Western blot方法检测心肌HSP 70的表达,电镜下观察给药后3 h时心肌细胞的病理学结果.结果 与C组相比,K组和BI组给药后3、6、12及24 h时HSP 70表达上调(P<0.05);与B组相比,K组给药后3、6 h时HSP 70表达上调(P<0.05).K组较BI组给药后3 h时心肌病理损伤减轻.结论 氯胺酮通过上调心肌HSP 70表达,减轻严重烧伤早期大鼠心肌损伤.

Effect of ketamine on the expression of HSP 70 in myocardium in severely burned rats

Objective To investigate the effect of ketamine on the expression of HSP 70 in myocardium in severely burned rats for its possible mechanism of myocardial protection. Methods Seventy-two male Wistar rats were randomly divided into 3 groups: normal control group (group C, n=8), burn injury group (group BI, n= 32) and ketamine group (group K,n=32). 30% Wtal body surface area of Ⅲ degree burn model was developed in group BI and group K. Ketamine 20 mg/kg was injected IM in group K 15 min after the burn model was made. Equal volume of normal saline was given instead of ketamine in group BI. Group C received no treatment. The rats were sacrificed at 3, 6, 12 and 24 h after administration in group BI and group K respectively(8 rats at each time point). Myocardial samples were obtained for determination of the expression of HSP 70 by Western blot analysis. The myocardial ultrastructure was observed at 3 h after administration with electron microscope. Results The myocardial damage was milder in group K than in group BI. The expression of HSP 70 was significantly higher at 3, 6, 12 and 24 h after administration in group K and group BI than in group C(P<0.05).The HSP 70 expression was significantly higher at 3 and 6 h after administration in group K than in group BI ( P<0.05). Conclusion Ketamine can reduce the myocardial injury induced by severe burn through up-regulating the expression of HSP 70 in cardiocytes.