脊髓缺血性再灌注损伤和预处理保护作用的实验研究

目的：探讨缺血预处理对家兔须缺血性损伤的保护作用。方法：家兔18只，随机分为Ⅰ组（假手术组）、Ⅱ组（缺血预处理组）和Ⅲ组（缺血再灌组），每组6只，Ⅰ组开腹后，在左肾动脉起点以下0．5cm处暴露并分离腹主动脉即关腹；Ⅲ组一次性阻断腹主动脉血流30min，松夹后关腹；Ⅱ组阻断腹主动脉血流5min，松夹后再灌注10min（如此反复2次），最后再持续夹闭腹主动脉30min，松夹后关腹。结果：Ⅰ组术后后肢运动功能全部正常，光镜和电镜检查显示组织结构变化甚微。Ⅲ组术后后肢运动功能发生严重障碍，脊髓组织严重损伤，与Ⅲ组比较，Ⅱ组术后后肢运动功能障碍较轻微，须组织损伤明显减轻，神经功能评价各组差异具有显著性（P12h=0.006和P36h=0.001)。结论：缺血预处理能够促进神经功能的恢复，减轻脊髓组织损伤，提示预处理对脊因再灌注损伤具有保护作用。

Experimental study for ischemic reperfusion-induced spinal cord injury and protecting effect of ischemic preconditioning on its injury in the rabbits

Objective: To investigate the protecting effect of ischaemic preconditioning (IP) on ischaemic spinal cord injury in rabbit models. Methods: Eighteen rabbits were randomly divided into three groups named sham, IP and ischemic reperfusion groups and there were six rabbits in each group. The abdominal cavities of 6 rabbits were opened and the abdominal aorta exposed at left infrarenal 0.5 cm in sham group, and then abdominal wall was sutured. In ischemic reperfusion group and IP group, the same procedures were underwent before abdominal wall was sutured, and then the aorta was clamped for 30 min in the former, the aorta was repeatedly clamped 5 min and reperfused 10 min, in the later, followed by 30 min lamping. Results: In ischemic reperfusion group, there was severe function disorder of hindlimb motor, and the nervous tissue of the spinal cord was revealed severe injury by light and electron microscope. In IP group, there was light function disorder of hindlimb motor and the nervous tissue of the spinal cord indicated little injury compared with the ischemic reperfusion group. In the meantime, the hindlimb motor function was normal and the change of the nervous tissue of the spinal cord showed almost none in sham group. The nervous recovery scores for each group in 12h and 36h of post operation indicated significant difference (P 12h =0.006 and P 36h =0.001). Conclusions: IP could decrease the spinal cord injury and improve the nervous function. As a consequence, the ischemic preconditioning would protect ischemic reperfusion indued spinal cord injury.