雌激素对兔脊髓缺血再灌注损伤保护作用的机制研究

Protective effect of estrogen on spinal cord ischemia-reperfusion injury in rabbits

摘要:

研究雌激素对脊髓缺血再灌注损伤保护作用的机制。方法按随机数表字法把成年的新西兰大白兔分为A～E 5组，每组9 只。钳夹肾下腹主动脉20 min恢复再灌注；B 组，接受与A 组同样的麻醉和手术准备，但不行缺血/ 再灌注损伤；C 组，再灌注开始时从兔耳的缘静脉注射200μg/kg 雌激素；D 组，再灌注开始时从兔耳的缘静脉注射400μg/kg 雌激素；E 组，再灌注开始时从兔耳的缘静脉注射800μg/kg 雌激素。再灌注48 h后根据Tarlov 法对下肢的神经功能进行评分，然后取脊髓组织苏木素- 伊红染色法（HE）进行病理分析。结果Tarlov 评分中雌激素组的神经功能评分高于A组，与A 组比较有统计学意义（p <0.05）。组织病理表明脊髓的前角运动神经元出现凋亡，有显著坏死。A 组脊髓的前角运动神经元计数少于雌激素组，两者比较差异有统计学意义（p < 0.05）。结论雌激素可明显改善兔脊髓缺血再灌注的下肢神经功能，使脊髓的前角正常运动神经元的数量增加，减小缺血再灌注的损伤。

Abstract:

To evaluate the protective effect of estrogen on spinal cord ischemia-reperfusion injury in rabbits and its mechanism. Methods According to a random number table method, adult New Zealand rabbits were divided into A-E five groups with 9 in each group. In the rabbits of group A, infrarenal aorta was clamped for 20 min and then blood circulation was restored (reperfusion). The rabbits of group B received the same anesthesia and surgery as group A, but no ischemia-reperfusion injury. The rabbits of groups C, D and E had injection of estrogen 200, 400 and 800 μg/kg respectively through ear veins when reperfusion started. The neurological function of the lower extremities was scored according to Tarlov law 48 h after reperfusion. Then hematoxylin-eosin staining was used for pathological analysis of spinal cord. Results The neurological function scores of the groups C, D and E were significantly higher than those of the group A (p < 0.05). Histopathological study showed apoptosis and marked necrosis of the motor neurons in the anterior horn of the spinal cord. The number of anterior horn motor neurons in the group A was significantly smaller than that of the estrogen groups (p < 0.05). Conclusions Estrogen can significantly improve the neurological function of the lower limbs of rabbits with spinal cord ischemia and reperfusion, increase the number of normal motor neurons in the anterior horn of the spinal cord, and reduce ischemia-reperfusion injury.