严重体表烫伤早期TNF对骨骼肌蛋白质分解代谢影响的实验研究

Dynamic study of TNF effects on skeletal muscle proteolysis in early stage of severe scalding in rats

为探讨烧伤后骨骼肌蛋白质解分解代谢的变化规律及其可能机理，以３７％体表面积Ⅲ度烫伤大鼠为模型，于伤后１周内动态观察了创伤局部与远隔部位骨骼肌蛋白质分解代谢速率与ＴＮＦ含量的动态变化。结果提示：①创伤局部及远隔部位骨骼肌蛋白质分解速率的进行性增强是严重烧伤后负氮平衡的重要原因，尤以创伤局部蛋白质的分解更为重要。②创伤局部骨骼肌中ＴＮＦ含量明显高于远隔部位，但二者间存在显著相关关系，以近似的浓度时间曲线逐步增高，且与相应肌组织蛋白质分解代谢速率呈正相关。提示远隔部位骨骼肌中ＴＮＦ含量受创伤局部ＴＮＦ含量的影响，局部高浓度的ＴＮＦ可能是导致蛋白质分解的重要原因。③外源性ＴＮＦ－ＭｃＡｂ可阻断内源性ＴＮＦ的作用，提示细胞因子拮抗剂的应用可望开辟一种新的治疗途径。④严重烫伤后ＴＮＦ的产生既受局部炎症刺激的影响，又随创面感染的发生而明显增加。

In order to invesigate the pattern of protein catabolic changes of the skeletal muscles after severe burns and the possible mechanism,the protein catabolic rate and tumor necrosis factor(TNF)contnet of the skeletal muscles of the scalded region and remote region were dynamically observed in the first week after the rats were inflicted with 37%TBSA full thickness scalding,It was found that 1.the progressive aggravation of protein catabolism of the skeletal muscles of both the scalded and remote regions especially that of the scalded region was the main cause of negative nitrogen balance after burn injury;2.the TNF content of skeletal muscles was far higher in the scalded region than in the remote region but the TNF increase of the 2 regions was significantly correlated and increased gradually in a similar content-time cruve.TNF increase was also significantly correlated to the protein catabolic rate of the skeletal muscles.These facts imply that the TNF increase of the muscles of the remote region is affected by that of the scalded region and local high TNF content may be an important cause to result in increased protein catabolism;3.Exogenous TNF monoclonal antibodies could block the effects of endogenous TNF,which suggests that cytokine antagonists may open a new route of treatment;and 4.TNF production after severe scalding was stimulated by local inflammation and subsequent wound infection and the latter played a more impormtant role.