细胞外ATP对坐骨神经损伤后脊髓前角运动神经元保护作用的实验研究

目的 探讨腹腔注射细胞外ATP对大鼠坐骨神经损伤后脊髓前角运动神经元的保护作用。方法 雄性SD大鼠48只，体重180～220g，随机分成两组。将大鼠左侧坐骨神经于梨状肌下缘0．5cm处切断，随即行显微外科外膜吻合术。手术后实验组腹腔注射ATP0．4ml（2mg／kg），对照组腹腔注射生理盐水0．4ml。分别于手术后7、14、28d应用甲苯胺蓝染色、酶组织化学染色检测神经损伤侧的脊髓前角运动神经元存活率和胆碱酯酶（ChE）及酸性磷酸酶（ACP）的变化。结果 伤后7、14和28d，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9．11％、8．64％和9．15％（P〈0．01）；脊髓前角运动神经元中ACP分别下降了108．74％、94．57％（P〈0．01）和10．82％（P〈0．05）；ChE活性变化幅度分别增加了5．82％、6．10％和3．99％（P〈0．01）。结论 腹腔注射细胞外ATP对坐骨神经损伤后引起的神经元死亡有保护作用。

An experimental study on protective effect of extracellular ATP to motor neurons in anterior horn of spinal cord after sciatic nerve injury

Objective To discuss the protective effect of extracellular ATP to motor neurons in anterior horn of spinal cord after sciatic nerve injury by intraperitoneal injection in rats. Methods Forty eight male Sprague-Dawley rats weighing 180~230 g, were randomly divided into two groups. Epineurorrhaphy was done after transection of the left sciatic nerve where there were 0.5 cm distance away the nether edge of piriformis. The experiment group was given extracellular ATP(2 mg/kg, 0.4 ml)by intraperitoneal injection and contral group was given physiological saline 0.4 ml as the same method. At 7,14 and 28 days after sciatic nerve transection, the status of motor neuron death in spinal anterior horn were observed by toluidine blue staining at the side of injury sciatic nerve, and the activity changes of cholinesterasec ChE, and acid phosphatasec (ACP) in spinal horn observed by enzyme histochemical staining at the same days. Results compare experiment group with control group, at days 7, 14, 28 after sciatic nerve transection, the lesion-induced motor neuron death in the spinal anterior horn was decreased by 9.11%, 8.64% and 9.15% respectively(P<0.01). the activity changes of ACP was decreased by 108.74%, 94.57%(P<0.01) and 10.82%(P<0.05)respectively, and the activity changes of ChE was increased of 5.82%, 6.10% and 3.99% respectively(P<0.01). Conclusion These results suggest that extracellular ATP can protect motor neurons from death after sciatic nerve injury by intraperitoneal injection.