Objective To investigate the effects of ischemic preconditioning (IPC) on aquaporin-4 expression in rabbit spinal cord following spinal ischemia-reperfusion injury. Methods Seventy-two Japanese white rabbits were randomly divided into 3 groups:sham operation(S group), spinal ischemia-reperfusion injury (I/R group) and IPC (IPC group). Spinal ischemia-reperfusion injury was induced by clamping the abdominal aorta below renal artery for 30 min in I/R and IPC groups. IPC was implemented by transient occlusion of the abdominal aorta for 5min twice before injury. S group was subjected to exposure of abdominal aorta but without occlusion. At 4h and 24h neurological function was evaluated and ischemic lumbar segment (L4-6) was removed for measurement of water content and AQP-4 protein expression. Results Compared with those of the S group, neurological function score was significantly lower, water contents were higher and AQP-4 expression was increased in the I/R group. Compared with those of the I/R group, neurological function score was increased, water contents were lower and AQP-4 expression was decreased in the IPC group. Conclusion IPC can inhibit AQP-4 expression after injury, and then ameliorate the spinal cord edema and spinal ischemia-reperfusion injury.%目的 探讨缺血预处理(IPC)对兔脊髓缺血再灌注损伤后水通道蛋白-4(AQP-4)表达的影响.方法 日本大耳白兔72只,随机分为3组:假手术组(S组)、脊髓缺血再灌注损伤组(I/R组)和缺血预处理组(IPC组).I/R组和IPC组阻断腹主动脉30min造成脊髓缺血再灌注损伤,IPC组在损伤前短暂阻断腹主动脉5min二次实施预处理,S组暴露肾动脉下腹主动脉但不阻断.分别于再灌注损伤后4h和24h进行神经功能评分,并取L4-6脊髓缺血节段,计算脊髓组织含水量,免疫组化法测定脊髓组织中AQP-4表达水平.结果 与S组比较,I/R组神经运动功能评分降低,脊髓组织含水量增加,AQP-4表达增加(P＜0.05).与I/R组比较,IPC组神经运动功能评分增高,脊髓组织含水量降低,AQP-4表达减少(P＜0.05).结论 IPC可抑制脊髓损伤后AQP-4的表达,进而减轻脊髓水肿,保护缺血再灌注损伤的脊髓.
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