Change of m-calpain in transected and sutured sciatic nerve of rat

Wallerian变性诱导横断周围神经的神经丝变性。已有研究表明，m-钙蛋白酶存在于大鼠坐骨神经中，并可能在Wallerian再生过程中发挥重要作用。获得8周龄雄性Wister大鼠。在右髋关节后下部锐性切断右侧坐骨神经，并将切断的末端回缩以防止再生。在显微镜下用10-0尼龙线缝合左侧坐骨神经。坐骨神经治疗后（仅横断或缝合），第二天（第一天）、第三天、下周（第一周）、第二周、第四周、第六周、第八周、第十二周和第十六周，在近端8 mm和远端8 mm处获得（仅横切或缝合）。将每个样品分成两个等分试样，测定第一个等分试样的蛋白质，对第二份等分试样进行Western印迹分析。每个样品通过蛋白质浓度标准化。为了定量，在时间过程实验中，缝合和切断的坐骨神经近端和远端的m-钙蛋白酶的量增加。但在缝合的神经中，近端的m-钙蛋白酶量在第8周后减少，远端的m-钙蛋白酶量在第12周后趋于减少。相反，在横断的神经中，看不到这种趋势。鉴于许多关于calpain抑制剂作为神经保护剂的报道，在Wallerian变性过程中，早期calpain发挥积极作用，但在晚期，calpain可能是周围神经正常再生的抑制剂。

Wallerian degeneration induces neurofilament degeneration in transected peripheral nerve. It has been reported that m-calpain exists in rat sciatic nerve and may play a significant role during Wallerian regeneration. Eight-week-old male Wister rats were obtained. The right sciatic nerve was cut sharply at the postero-inferior portion of right hip joint and the transected ends were retracted to prevent regeneration. The left sciatic nerve which was transected was sutured with 10-0 nylon monofilament with microscope. After sciatic nerves were treated (transected only or sutured), on next day (first day), third day, next week (first week), second week, fourth week, sixth weed, eighth week, twelfth week and sixteenth week, the nerve ends (transected only or sutured) were obtained at proximal 8 mm and distal 8 mm. Each sample was divided into two aliquots, the first aliquot was assayed for protein, the second aliquot was subjected to Western blot analysis. Each sample was normalized by the concentration of protein. In order to quantity the amount of m-calpain at proximal and distal ends of sutured and transected sciatic nerves increased in time course experiments. But in the sutured nerves, the amount of m-calpain at proximal ends decreased after eighth week, and at distal ends tended to diminish after twelfth week. In contrast, in the transected nerves, the tendency could not be seen. In view of many reports of calpain inhibitors as neuroprotectors, during Wallerian degeneration, in early stage, calpain play a positive role, but in late stage, calpain may be an inhibitor of normal regeneration of peripheral nerves.