陈旧性坐骨神经缺损对大鼠腓肠肌组织蛋白含量及泛素表达的影响

目的：了解陈旧性坐骨神经缺损后肌肉萎缩过程中蛋白质降解的机制。方法：用SD大鼠建立坐骨神经缺损模型,切断大鼠右侧坐骨神经,形成10 mm缺损。测定术后1、2、3、4、6、9及12个月腓肠肌肌总蛋白的含量；免疫组化法观察组织中泛素的表达变化；Western印迹法测定组织中泛素蛋白的表达水平。结果：坐骨神经缺损后腓肠肌肌总蛋白含量随缺损时间延长呈进行性下降；正常腓肠肌组织中泛素呈低表达,随缺损时间延长泛素表达水平增强,持续到9个月,随后呈下调趋势。结论：陈旧性坐骨神经缺损后腓肠肌蛋白的降解、肌总蛋白量下降及肌萎缩可能和泛素-蛋白酶体途径有关。

Effect of long-term sciatic nerve denervation on protein content and ubiquitin expression in rat gastrocnemius

Objective:To study the mechanism of protein degradation during muscle atrophy following long-term denervation.Methods:The right sciatic nerves of adult SD rats were transected into 10 mm denervation.In the 1st,2nd,3rd,4th,6th,9th and 12th month after surgery,total protein,the expression of ubiquitin and ubiquit inated proteins of denervated gastrocnemius were detected hy immunohistochemistry and Western blot.Results: There was a significant decrease of total protein of denervated gastrocnemius after the sciatic nerve was transec- ted.Meanwhile,ubiquitin levels of denervated gastrocnemius increased until the 9th month post injury,and then decreased,and kept low at normal gastrocnemius.Conclusion:In long-term denervated gastrocnemius,ubiquitin- protease pathway may be correlated to protein degradation,total protein decrease and muscle atrophy.