热休克预处理对脊髓缺血再灌注损伤的保护作用

目的 研究热休克预处理对兔脊髓缺血再灌注损伤的保护作用及相关机制。方法 将新西兰白兔66只随机分为3组：①假手术组(sham-operation，s组)6只；②缺血再灌注组(ischemia／reperfusion，I／R组)30只；③热休克预处理组(heat shock precondit，ioning，HP组)30只。缺血再灌注后8h，16h，24h，48h，72h从I／R组和HP组随机抽取6只兔，检测后肢运动功能，并取脊髓组织行免疫组化染色观察热休克蛋白70(heat shock protein 70，HSP70)的表达，TUNEL染色观察神经元凋亡情况。脊髓匀浆液检测超氧化物歧化酶(SOD)活力及脂质过氧化物丙二醛(MDA)的含量。结果 各个时间点上，HP组的运动功能评分优于I／R组；免疫组化染色，HP组阳性率远高于I／R组；TUNEL染色，HP组阳性率低于I／R组；SOD的活力HP组高于I／R组，MDA含量HP组低于I／R组。结论 热休克预处理后可能产生了大量HSP，并提高了SOD活力，通过抑制神经元周亡，减少自由基对脂质膜的破坏等途径对脊髓缺血再灌注损伤产生保护作用。

The Protective Effects on Ischemia-reperfusion Injury in Rabbit Spinal Cords by Heat Shock Preconditioning

Objective To study the protective effects and the mechanism on ischemia-reperfusion injury in rabbit spinal cords by heat shock preconditioning. Methods Sixty-six rabbits were randomly divided into 3 groups: sham-operation group(S group), 6 rabbits, ischemia/reperfusion group, (I/R group) 30 rabbits and heat shock preconditioning group(HP group), 30 rabbits. At the 8th, 16th, 24th, 48th and seventy 2nd hour after reperfusion, 6 rabbits of I/R and HP groups were picked out randomly, their locomotive function of posterior limbs was assessed according to Jacob's score, then they were sacrificed. The spinal cords were removed. We examined the expression of heat shock protein 70 by immunohistochemical staining, the apoptosis of nerve cells by TUNEL staining method, and measured the spinal SOD and MDA. Results At the time observed, the Jacob's score of HP group was better than that of I/R group. A large accumulation of HSP70 was observed in HP group, but not in I/R group. More TUNEL-positive nerve cells were observed in I/R group than those in HP group. The SOD activity was higher in HP group than that in I/R group. The content of spinal MDA was lower in HP group than that in I/R group. Conclusion A lot of HSPs are induced and the SOD activity is raised after heat shock preconditioning. The mechanism of its protective effects may be related to reducing apoptosis and prohibiting oxidation after reperfusion.