细胞外ATP对臂丛神经根性撕脱伤后脊髓运动神经元保护的实验研究

An experimental study on protective effect of extracellular ATP to motorneurons on spinal cord after brachial plexus avuision

目的 观察细胞外ATP对臂丛神经根性撕脱伤所致脊髓前角运动神经元损伤的保护作用。方法Wistar大鼠36只，随机分为两组：单纯神经根撕脱组和神经根撕脱加ATP治疗组。行左侧臂丛神经根性撕脱术，术后实验组腹腔注射ATP（2mg／kg）0．4ml，对照组腹腔注射生理盐水0．4ml，均为1次／日，连续应用ATP或生理盐水2周。术后2周、4周和6周后取材，处死动物后取C5～C8脊髓分别行一氧化氮合酶（NOS）、神经丝蛋白（NF-200）免疫组织化学染色。结果术后2、4和6周，实验组脊髓前角运动神经元存活率为80．48％、73．55％、53．43％，对照组为68．90％、63．58％、37．72％，实验组与对照组比较脊髓前角运动神经元死亡率分别降低了11．58％、9．87％和15．71％（P〈0．01）；实验组脊髓前角运动神经元中NOS阳性率为17．85％、40．20％、18．03％，对照组为25．53％、53．88％、25．58％，实验组与对照组比较．脊髓前角运动神经元中NOS阳性率分别下降了7．68％（P〈0．01）、13．68％和7．55％（P〈0．05）；实验组脊髓前角运动神经元的NF-200阳性细胞数均高于对照组，两者比较差异有统计学意义。结论ATP对臂丛神经根性撕脱伤后脊髓前角运动神经元具有保护作用。

Objective To investigate the protective effect of extracellular ATP on motoneurons of spinal anterior horn from spinal root avulsion induced cell injurey. Methods Thirty-six Wister rats were randomized into 2 groups： single root avulsion and root avulsion with ATP. The left C5-C8 nerve roots were avulsed, the experiment group was given extracellular ATP （2 mg/kg） 0.4 ml by intraperitoneal injection and control group physiological saline water was given 0.4ml as the same method, all one time daily, continue injection ATP or saline water 2 weeks. At 2,4 and 6 week postoperatively, C5-C8 spinal cord was harvested after the rats were executed. The change of nitric oxide synthase （NOS） and neurofilament protein （NF-200） were observed after histochemistrical examination. Results At 2.4 and 6 week postoperatively, the survival of motomeurons in the spinal anterior was 80.48%,73.55% and 53.43% in experiment group, was 68.90%,63.58% and 37.72% in control group;compare experiment group with control group, the lesion-induced motorneurons death in the spinal anterior horn was decreased by 11.58%,9.78% and 15.71% respectively （P 〈 0.01）; the activity changes of NOS expression rate was 17.85%,40.20% and 18.03% in experiment group, was 25.53%, 53.88% and 25.58% in control group, compare experiment group with control group, the activity changes of NOS expression rate was decreased by 7.68% （P 〈 0.01）, 13.68% and 7.55% （P 〈 0.05） respectively. The motoneurons expressed NF-200 in the experiment group was larger than the control group, there was significant difference was found between the control group and the experiment group. Conclusion ATP might play certain protective role in survival of motoneurons after spinal root avulsion.