MnTBAP对大鼠急性脊髓损伤的保护作用

摘要

Objective To investigate the neuroprotective effects of MnTBAP on neurological tissue after spinal cord injury in rats. Methods A total of 60 health male SD rats were randomly divided into sham group(A),SCI control group(B)and MnTBAP treatment group(C).The model of spinal cord injury in rats was established by Allen method.B、C group were administered NS and MnTBAP respectively after model creation.The contents of MDA and SOD according to 6h、12h、24h and 72 h after model creation were measured with spectrophotometry.Neuronal apoptosis rate was monitored by TUNEL staining method.The motor function recovery of rats was evaluated with BBB score every week. And the morphological changes were observed by HE staining on the 28th day. Results The activity of SOD in B and C group were significantly lower than A,while the treatment group can obviously prevent the reduction of SOD activity(P<0.01).The content of MDA and the apoptosis rate were significantly decreased in the treatment group as compared with control group(all P<0.05).7 days after operation,the BBB score of C group was higher than B group(P<0.05). With HE stain,damages of the spinal cord could be seen in both B and C group,but the SCI group has more necrotic scar tissues and cavity,with less nerve cell than the MnTBAP group. Conclusion MnTBAP can exert the biological activity of SOD,decreasing early spinal cord lipid peroxidation and cell apoptosis rate. It can reduce the secondary injury of spinal cord in rats so as to protect the nerve.%目的：观察锰卟啉（MnTBAP）在大鼠急性脊髓损伤后对脂质过氧化水平，细胞凋亡，脊髓组织变化及运动功能的影响，探讨其对急性脊髓损伤后的保护性作用。方法将60只SD大鼠随机分成3组：假手术组，损伤组（SCI组）及治疗组。应用改良的Allen法，制成脊髓损伤模型。假手术组仅予椎板切除处理；治疗组注射MnTBAP（10mg/kg）；损伤组仅腹腔注射等量生理盐水。各组分别于术后不同时间点检测SOD，MDA的含量，并采用TUNEL法计算细胞凋亡率；术后第l周至第8周，每周采用改良BBB评分对动物进行行为学检查；术后4周行HE染色，观察脊髓组织形态学变化。结果与损伤组比较， MnTBAP治疗组伤段脊髓组织SOD含量显著增加（P<0.01），相反，MDA含量明显减少（P<0.05）。损伤后第3、7、14天治疗组凋亡细胞率明显低于损伤组（P<0.05）；自第1周开始MnTBAP治疗组BBB评分明显高于损伤组（P<0.05）。4周后HE染色示损伤组脊髓大量瘢痕连接，结构紊乱，局部伴明显空洞形成，神经元胞体萎缩变形，神经纤维排列紊乱。而MnTBAP组脊髓组织空洞显著较小，周围存在较多的神经元细胞，液化坏死现象及炎症细胞较少。结论 MnTBAP可以发挥SOD活性，降低SCI早期脊髓脂质过氧化反应，减少脊髓MDA水平及凋亡率，有效减轻脊髓继发损伤，从而达到对大鼠脊髓损伤后的神经保护性作用。