大鼠坐骨神经挤压伤后血清SOD,MDA变化及脊髓神经细胞凋亡初步观察

The Change of SOD,MDA in Serum and Apoptosis of the Spinal Cord after Sciatic Nerve Crush Injury in Rats

目的研究坐骨神经挤压伤后血清SOD,MDA表达变化和细胞凋亡的规律及三者之间的关系。方法成年SD大鼠36只随机分为神经挤压组和假手术组。1,2,3周每组分别处死6只大鼠,用硫代巴比妥酸(thiobarbituric acid,TBA)法测定MDA含量,黄嘌呤氧化酶(xanthine oxidase,XO)法测定SOD,TUNEL法标记凋亡细胞,计算凋亡指数。结果①与假手术组相比,7d,14d大鼠血清中SOD含量下降,MDA含量升高,组间比较,差异均有显著性(P<0.05),7d达峰值,以后SOD逐渐上升,MDA逐渐下降。21d假手术组与手术组比较,差异无显著性(P>0.05);②手术组7d,14d大鼠脊髓神经细胞凋亡率比假手术组大鼠相应部位的神经细胞凋亡率增加,组间比较,差异有显著性(P<0.05)。到21d与假手术组比较,差异无显著性(P>0.05);③神经细胞凋亡率与SOD活性呈负相关(r<o,P<0.05),与MDA含量呈正相关(r>0,P<0.05)。结论坐骨神经挤压伤后血清SOD,MDA含量变化与脊髓神经细胞凋亡发生发展有关,氧化损伤可能是诱发细胞凋亡的机制之一。

Objective To study the characteristic of apoptosis and the the relation among them after sciatic nerve crush injury （ CCI ） in rats. Methods expression of SOD/MDA, as well as Adult SD rats were divided into two groups randomly：sham operation group and CCI group. The rats were killed at 7,14,21d after surgery.＂ The expression of T-SOD level was measured by xanthine oxidase （ XO } method. The MDA level was examined by the thiobarbituric acid {TBA ） method and the apoptosis was labeled by TUNEL. Results The SOD level decreased and the MDA level increased significantly on 7 and 14 day（ P 〈0.05 }. After 7 days,SOD level gradually increased but MDA level decreased. On 21 st day, there was no difference between the two groups. Compared with the sham operation group, the apoptosis rate in the CCI group increased significantly after 7 and 14days（ P 〈 0.05 }. The apoptosis rate correlated negatively with SOD activity （ r 〈 0, P 〈 0.05 ） but positively with MDA content （ r 〉 0, P 〈 0.05 }. Conclusion It indicated that after ：CCI in , ! rats the level of SOD and MDA in serum played an important role in the development of the neuron apoptosis in the spinal cord. The oxidative damage might be one of the mechanisms of apoptosis.