缺血预处理对兔脊髓缺血再灌注损伤水通道蛋白-4表达的影响

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。

Effects of ischemic preconditioning on aquaporin-4 expression in spinal cord following spinal ischemia-reperfusion injury in rabbits

Objective To investigate the effects of ischemic preconditioning （IPC） on aquaporin-4 ex- pression 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 5rain twice before injury. S group was subjected to exposure of ab- dominal 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. Re- sults 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.