辛伐他汀对脊髓缺血再灌注损伤后热休克蛋白70的影响

Effects of simvastatin on heat hock protein 70 after spinal cord ischemia reperfusion injury

目的 观察辛伐他汀对猪脊髓缺血再灌注损伤（SCII）后热休克蛋白70（Hsp70）表达的影响。方法 24头健康成年西藏小型猪,雌雄不限,体质量20-30kg,随机分为假手术组（C组）、缺血再灌注损伤组（L/R组）和辛伐他汀实验组（Sim组）,每组8头。I/R组和Sim组采用胸主动脉、锁骨下动脉阻断法造成脊髓缺血再灌注损伤模型（70 min）,分离副半奇静脉,远端结扎,近端插管。I/R组在阻断过程中副半奇静脉逆灌注乳酸林格钠液（860 ml/h,1000 ml）,Sim组阻断过程中副半奇静脉逆灌辛伐他汀溶液（0.25 mg/kg,1000 m1）,术后口服辛伐他汀片剂80 mg/d,30 d。术后采用Tarlov下肢神经功能评分系统评估6、24、48 h神经运动功能。术后30 d,各组分别处死8头实验猪,迅速取出来L2-L5及骶段脊髓,苏木素-伊红（HE）、Nissle染色观察神经元形态学变化,免疫组织化学法检测Hsp70的表达。结果 Sim组术后24、48 h神经功能评分[（3.2±0.3）、（3.6±0.2）分]高于I/R组[（2.2±0.4）、（2.8±0.4）分],差异有统计学意义（P〈0.05）。与I/R组比较,Sim组神经元形态学的损伤较轻,Hsp70表达明显增加,其积分吸光度值为296.804 6±3.695 1。结论辛伐他汀对猪脊髓缺血再灌注损伤具有保护作用,其机制可能和诱导Hsp70的表达上调有关。

Objective To investigate the protective effect of simvastatin on spinal cord ischemia/ reperfusion injury through the observation of the changes of heat shock protein 70 （Hsp70）. Methods 24 healthy adult Tibet mini-pigs of either sex, weighted 20-30 kg, were randomly divided into three groups （n = 8 ） , including sham operation group （group C） , ischemia/reperfusion group （group I/R） and simv- astatin experimental group （group Sire）. In group I/R and Sire, the models of spinal cord isehemia/reper- fusion were established by the occlusion of thoracic aorta and subclavian artery （70 rain）. The accessory hemiazygos vein was isolated and the distal end was ligated. In group I/R, 1000 ml lactated ringer solution were pumped into the vein and the rate was 860 ml/h during the ischemia time. In group Sire, 1000 ml simvastatin solution were pumped into the vein and the dose was 0. 25 mg/kg during the ischemia time. Feed the swines of the experimental group simvastatin tablets 80 mg/d, orally for 30 days. After the operation, the motor function scores were recorded at 6, 24, 48 h （see Taylor motor function scoring system）. All eight swines of each group were killed at 30 days after reperfusion, taking the L2-L5 and sacral spinal cord as quickly as possible. The hematoxylin and eosin （HE） staining method and the NISSLE staining method were adopted to observe the morphological changes of neurons and the immunohistochemical method was adopted to detect the changes of Hsp70. Results In group Sim, the 24, 48 h motor function scores （3.2 ± 0. 3, 3.6 ± 0. 2 respectively） after operation were significantly higher than that in group I/R （2. 2 ±0. 4, 2. 8 ±0. 4 respectively） （P 〈0. 05）. Compared with group l/R, the morphology of neurons in group Sire had a slight damage and higher expression changes of Hsp70 can be found in group Sim （P 〈 0. 05 ）. Conclusion Simvastatin has a significant protective effect on the spinal cord ischemia reperfusion injury and the potential mechanism may be related to the up-regulation of Hsp70.