热休克预处理对严重烫伤大鼠胃黏膜热休克蛋白60、70及iNOS表达的影响

目的 观察热休克预处理对严重烫伤大鼠胃黏膜热休克蛋白(heat shock protein ,HSP)(HSP60、HSP70)和诱生型一氧化氮合酶(induced nitric oxidase synthase,iNOS)表达的影响,探讨热休克预处理对严重烫伤大鼠胃黏膜的保护作用机制.方法 将Wistar大鼠分为烫伤组及热休克预处理后烫伤组2个大组,观察不同处理组大鼠胃黏膜损伤指数(ulcer index,UI)变化.同时应用RT-PCR技术检测各组大鼠胃黏膜HSP70 mRNA表达,免疫组化染色分析胃黏膜组织中HSP60 、HSP70、iNOS表达变化.结果 正常大鼠严重烫伤后iNOS表达显著增强,胃黏膜损害明显,热休克预处理能显著减轻大鼠严重烫伤后急性胃黏膜损害;与烫伤组比较,经热休克预处理后再烫伤大鼠胃黏膜HSP60 和HSP70基因表达水平升高(P＜0.05),尤以HSP70为甚(P＜0.01),而iNOS表达受抑(P＜0.01).结论 热休克预处理对大鼠严重烫伤后急性胃黏膜损害具有保护作用,其保护机制可能与HSP60、70诱导表达增强及iNOS表达受抑等机制有关.

Effects of heat shock preconditioning on expressions of HSP60, HSP70 and iNOS in gastric mucosa of burned rats

Objective To observe the influence of heat shock preconditioning on the expressions of heat shock protein(HSP)60,70 and induced nitric oxidase synthase(iNOS)in gastric mucosa of severely burned rats and investigate the protective mechanism of burn-induced acute gastric mucosal lesion.Methods Ninety-six Wistar rats were divided into two groups:burn(B)and heat shock preconditioning before burn(HB).The extent of gastric mucosal lesions(UI)was evaluated grossly and histologically.HSP70 mRNA expression was determined by RT-PCR.Immunohistochemical method was used to analyze the protein expressions of iNOS,HSP60 and HSP70.Results Rats in B group were induced conspicuous gastric mucosal lesions,while UI in HB group was significantly lower.The expressions of HSP70 and HSP60 were significantly increased and the expression of iNOS was obviously decreased in HB group as compared with B group.Conclusion Heat shock preconditioning protects against acute gastric mucosal lesion caused by burn through enhancing the expressions of induced HSPs and reducing the iNOS expression.