细胞外ATP对失神经支配后骨骼肌和脊髓前角运动神经元ATPase活性的影响

Effects of extracellular ATP on the ATPase activity of denervated skeletal muscles and motor neurons of spinal cord anterior horn

目的了解细胞外三磷酸腺苷(adenosine triphosphate,ATP)对坐骨神经损伤后腓肠肌和相应脊髓节段ATPase活性的影响。方法SD大鼠168只,切断其右侧坐骨神经后,随机分为3组,每组56只。损伤组：坐骨神经离断后不修复。对照组和实验组在坐骨神经离断修复后．于腓肠肌内注射同体积的生理盐水和ATP。术中和术后每日用药1次至取材为止。3组分别于手术后12 h、1 d、3 d、7 d、14 d、28 d、56 d时每组各取8只大鼠。测定腓肠肌和L_(4～6)水平脊髓前角运动神经元Na-K-ATPase及Ca-AIPase活性。术后7 d、14 d、28 d、56 d取双侧腓肠肌称肌湿重。结果实验组术后能显著改善ATPase的活性,这种改变与肌湿重的变化相一致．与损伤组和对照组相比差异有统计学意义(JP＜0．05)。结论细胞外ATP可通过对ATPase的影响,对失神经骨骼肌和脊髓前角运动神经元具有一定的保护和促进功能恢复作用。

Objective To investigate the effect of extracellular ATP on ATPase activity of denervated gastrocnemius muscle and motor neurons of anterior horn of the spinal cord following sciatic nerve injury in Sprague Dawley rats. Methods 168 Sprague-Dawley rats were randomly divided into three groups. The right side sciatic nerves were transeeted hut not sutured in injury only group. The right side sciatic nerves were transected and immediately sutured in experimental group and control group, rats in the former being given intra-gastrocnemius injection of ATP while rats in the latter being given intra-gastrocnemius injection of normal saline. 12 hours, 1 day, 3 days, 7 days, 14 days, 28 days and 56 days following the surgery, muscle wet weight and Na-K-ATPasc and Ca- ATPase activities in the gastrocnemius muscles and motor neurons of L4-6 spinal cord anterior horns were measured. Results The ATPase hioactivity in the experimental group was higher than that in the injury only group and control group. This change was in accordance with the change of the muscle wet weight. The difference was statistically significant. Conclusion Extracellular ATP might have certain protective and promoting regeneration effects on denervated skeletal muscles and motor neurons via enhanced ATPase activity.