严重烫伤大鼠骨骼肌蛋白质降解途径及泛素作用的研究

Study of Proteolytic Pathway and Role of Ubiquitin on Skeletal Muscle Protein Degradation in Severe Scalded Rats

目的阐明严重烧伤后蛋白质降解的主要途径，以期为伤后代谢调理和防治提供理论依据。方法以包括一侧后肢３７％体表皮肤全层严重烫伤大鼠为模型，分别抑制不同蛋白质降解途径，以荧光分光光度法测定比目鱼肌酪氨酸体外总释放量，并采用Ｗｅｓｔｅｒｎｂｌｏｔ法观察泛素含量的变化。结果阻断依赖ＡＴＰ－泛素途径后，能显著抑制大鼠伤肢蛋白质降解。同时，泛素含量均呈明显的进行性增加。

Aim To find out the main proteolytic pathway induced by severe burn injury for the prophylaxis and treatment of metabolic changes after burn. Methods Wistar rats inflicted with 37% TBSA third degree scald injury used as the animal models and inhibitors of different proteolytic pathway on the protein degradation of the skeletal muscle were used to determine the release of tyrosine by fluorescence spectrography. The level of ubiquitin was further examined by Western blot. Results When the ATP ubiquitin proteasome complex dependent proteolytic system was maximally inhibited after burn, the increased blockade in proteolysis of injured limb was 85.7%, 35.2% and 4.7%, respectively. Additionly the content of ubiquitin had a markedly progressing enhancement on the 1st, 2nd and 3rd day after scald. Conclusion Severe burn injury causes an large activation of an ATP ubiquitin proteasome complex dependent proteolytic process, which accompanys the notable increase of ubiquitin content.