摘要
目的探讨大鼠烫伤后骨骼肌蛋白质降解增强的机制和TNFα作用的关系。方法以30 %和37 %TBSA全层烫伤大鼠为模型 ,观察局部和远隔部位比目鱼肌泛素(Ub)含量、酪氧酸(Tyr)释放量、血清TNFα水平及TNFα作用下比目鱼肌Ub和UbmRNA表达水平。结果TNFα注射后24h内比目鱼肌Ub、UbmRNA、Tyr释放量均显著增加。烫伤后伤肢Ub含量、Tyr释放量皆显著增加 ,变化趋势一致 ;未伤肢Ub增加而Tyr释放量增加不明显 ;血清TNFα水平显著升高。TNFα处理后烫伤大鼠伤肢、未伤肢比目鱼肌Ub含量、Tyr释放量皆显著升高 ,且伤肢变化更显著。烫伤、TNFα的交互效应显著。结论烫伤可能借烫伤局部产生的TNFα作用于Ub依赖系统促进烫伤局部骨骼肌蛋白质降解。
Objective To study the mechanism of intensified proteolysis of skeletal muscles after severe scalding in rats and its relation with TNFα. Methods Rats with 30% and 37% TBSA full thickness scalding served as the animal model. The content of ubiquitin (Ub) and the amount of tyrosine released in the soleus muscle and in the scalded and remote regions were determined. The serum level of TNFα was measured. In addition, the expression of Ub protein and mRNA in the soleus after the injection of TNFα was observed. Results 24 hours after TNFα injection, the expression of Ub protein and mRNA and the amount of tyrosine release in the soleus were significantly increased. The Ub content and the amount of tyrosine release were significantly increased in a similar tendency in the scalded limb; in the unscalded limb, the increase of Ub content was observed but no significant increase of tyrosine was found. After the treatment of TNFα, Ub content and the amount of tyrosine release in the soleus were markedly increased in both the scalded and unscalded limbs but the changes were more marked in the scalded one. The cross effects of scalding and TNFα were clearly observed. Conclusion After scalding, the production of certain amount of TNFα induced by scalding itself can act on the Ub-dependent system to promote proteolysis of skeletal muscles in scalded region.
出处
《第三军医大学学报》
CSCD
北大核心
2000年第4期341-344,共4页
Journal of Third Military Medical University
基金
全军"九五"指令性攻关项目!(96L043)
