HSP70在严重烧伤大鼠心肌中的表达及其保护作用的研究

目的 研究热休克蛋白70(HSP70)在严重烧伤大鼠心肌中的表达变化规律，并观察诱导热休克反应对烧伤后心肌损害的保护作用。方法 72只Wistar大鼠随机分为单纯烫伤组(B组)、亚砷酸钠预处理组(SA组)，于致伤前及30％TBSAⅢ度烫伤后3、6、12、24、48h检测血清心肌钙蛋白Ⅰ含量变化，Western blot检测心肌组织HSP70蛋白表达情况。结果 大鼠严重烧伤后3h心肌组织HSP70蛋白表达显著升高，伤后48h达高峰。大鼠烫伤后3h血清心肌钙蛋白Ⅰ(cTnⅠ)含量即开始明显升高，伤后12h达高峰。亚砷酸钠预处理可显著诱导机体的热休克反应，SA组伤后多数时相点血清cTnⅠ含量显著低于B组，且波动幅度较小。结论 严重烧伤早期即可引起心肌组织HSP70蛋白表达显著增强，HSP70蛋白可能在烧伤后早期心肌损害中发挥其内源性抗损伤机制。

Expression of heat shock protein 70 in myocardium of severely burned rats and its protective effect

Objective To study the expression of heat shock protein 70 (HSP70) in myocardium and the protective effect of heat shock response on myocardium of scalded rats. Methods A total of 72 Wistar rats were randomly divided into 2 groups: simple burn group (B group) and sodium arsenite pretreatment group (SA group). Changes of serum cardiac troponin I(cTnI) content were determined at 0, 3, 6, 12, 24 and 48 h after 30% full thickness scald injury. Samples of myocardium were taken for the determination of HSP70 expression by Western blot analysis. Results HSP70 expression in myocardium increased significantly at 3 h after scald injury. The level of HSP70 was highest at 48 h after scald. Serum cTnI content increased significantly at 3 h after scald injury and reached the peak at 12 h after scald injury. Heat shock response could be induced by sodium arsenite pretreatment. SA group showed a significantly lower serum cTnI content. Conclusion Severe burn injury causes a significantly increased expression of HSP70 in myocardium. HSP70 may have endogenous anti injury effect on early burn injury of the myocardium.