Role of protease on spinal cord ischemia and reperfusion

我们研究了蛋白酶（Calpain）在脊髓缺血再灌注中的作用。对日本大白兔进行麻醉和机械通气。第四次左开胸夹持胸降主动脉。在主动脉夹紧前，calpain组静脉给予calpain抑制剂-1 (10 mu mol/kg) （n=7）。对照组（n=7）不给药。主动脉夹持20分钟后，取下夹持器，闭胸。采用Tarlov评分法进行48小时神经学观察。对照组7只家兔中6只发生完全截瘫，其余家兔发生重度瘫痪。钙蛋白酶组7只家兔中有3只未出现严重瘫痪，只有2只出现完全截瘫。两组间差异有统计学意义（p=0.017）。western blot结果显示，α -钙蛋白150-kD片段在完全缺血的脊柱中明显致密。提示钙蛋白酶在脊髓缺血再灌注中起重要作用。组织病理学检查显示对照组脊髓损伤，calpain组未见损伤。我们认为钙蛋白酶抑制剂-1可能对脊髓缺血再灌注有保护作用。

We investigated the role of protease (Calpain) on spinal cord ischemia and reperfusion. Japanese white rabbits were anesthetized and ventilated mechanically. 4th left thoracotomy was made for clamping the descending thoracic aorta. Just before aortic clamping, calpain inhibitor-1 (10 mu mol/kg) was administered intravenously in calpain group (n=7). Control group rabbits (n=7) received no inhibitor. After 20 minutes' aortic clamping, clamp was removed and chest was closed. Neurological observation was performed for 48 hours by means of Tarlov's score. 6 of 7 rabbits in control group developed complete paraplegia and remaining rabit developed severe paralysis. In contrast, 3 of 7 rabbits in calpain group were recovered without severe paralysis and only 2 rabbits developed complete paraplegia. There was significant difference between two groups (p=0.017). 150-kD fragment of alpha-calspectin was apparantly dense in complete ischemica spine by western blotting. It suggests that calpain play important role on spinal cord ischemia and reperfusion. Histopathology also revealed the spinal cord injury in control rabbit whereas no injury in calpain group.We conclude that calpain inhibitor-1 may protect spinal cord during ischemia and reperfusion.