Role of protease on spinal cord ischemia and reperfusion

我们研究了蛋白水解酶(钙蛋白酶)在脊髓缺血再灌流中的作用。日本大耳白兔机械麻醉，机械通气。4行左开胸夹闭降主动脉。Calain组(n=7)在主动脉阻断前静脉注射Calain抑制剂-1(10mU·mol/kg)。对照组(n=7)不给予任何抑制物。主动脉阻断20min后，取下主动脉，关闭胸腔。用Tarlov评分进行48h的神经功能观察。对照组7只兔中有6只发生完全性截瘫，其余兔出现严重瘫痪。Calain组7只兔中有3只恢复正常，未出现严重瘫痪，仅2只兔出现完全截瘫。两组比较差异有统计学意义(P=0.017)。Western blotting显示，完全性脑缺血脊髓组织中有明显致密的α-钙调素150-kD片段。提示钙蛋白酶在脊髓缺血再灌流中起重要作用。组织病理学检查显示对照组兔脊髓有损伤，而钙蛋白酶组未见损伤，提示钙蛋白酶抑制物-1对脊髓缺血再灌注损伤有保护作用。

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.