缺血预处理对脊髓缺血损伤细胞内Ca2+变化的影响

目的　观察缺血预处理对脊髓缺血损伤细胞内 Ca2 变化的影响。　方法　将 44只健康新西兰大白兔随机分为三组 :缺血组 2 0只 ,缺血预处理组 2 0只 ,假手术组 4只。缺血组于左肾动脉下夹闭腹主动脉 40分钟后开放灌注 ;缺血预处理组夹闭腹主动脉 5分钟 ,开放 15分钟 ,再次夹闭 40分钟后开放再灌注 ;假手术组动物手术操作同缺血组 ,但不夹闭腹主动脉。分别于夹闭 40分钟后即刻、开放再灌注 2小时、8小时、2 4小时和 72小时各时相点测定脊髓组织 Ca2 含量 ,并评定、记录动物后肢神经功能。　结果　缺血预处理组脊髓组织 Ca2 显著低于缺血组各时相值 ;再灌注 8小时后神经功能评分缺血预处理组明显高于缺血组 (P<0 .0 1)。　结论　缺血预处理具有降低神经元胞浆游离 Ca2 浓度 ,防止Ca2 超载 ,稳定细胞内环境的能力 ,对主动脉阻断所致的脊髓缺血损伤有良好的保护作用。其表现为明显降低瘫痪发生率 ,增加术后神经评分

Effect of Ischemic Preconditioning on the Change of Intercellular Calcium in Spinal Cord Ischemic Injury

Objective To study the effect of ischemic preconditioning(IPC) on the change of intercellular calcium in spinal cord ischemic injury associated with abdominal aortic cross clamping. Methods Forty four New Zealand white rabbits were randomly divided into ischemic group( n =20), IPC group( n =20) and sham group( n =4). In the ischemic group, the infrarenal aorta was occluded for 40 min by a Bulldog clamp, then released. In the IPC group, following reperfusion for 15 min after 5 min of abdominal aortic occlusion, the aorta was re clamped for 40min and then reperfused again. In the sham group, the procedure was the same as the ischemic group, but without abdominal aortic clamping. The concentrations of Ca 2 in spinal cord were measured at five different time intervals, 40min after clamping,2h,8h,24h and 72h after reperfusing, meanwhile the neurologic function was observed and recorded. Results After ischemic preconditioning, the Ca 2 level in spinal cord of the IPC group were significantly decreased than those in ischemic group ( P <0.05). After 8h of reperfusion, the neurological scoring of IPC group was significantly higher than that in ischemic group. Conclusion IPC can significantly decrease the degree of Ca 2 overload and IPC can protect the spinal cord from injury caused by aortic cross clamping.