臂丛端侧吻合术后供体神经元和运动终板中CGRP的变化

Effect of end-to-side neurorrhaphy of brachial plexus injuries on donor neurons and CGRP in motor endplate in rats

目的研究臂丛端侧吻合术后供体神经元和运动终板中CGRP的变化。方法Wister大白鼠60只,随机分为3组,每组20只,每只右侧神经外膜开窗(0.2 cm×0.2 cm),将臂丛后束损伤后的桡神经远断端端侧吻合于外膜开窗的内侧束远端0.5 cm部位,左侧不做吻合。分别于术后4、8、12周在麻醉下解剖取C4～T2脊髓节段,并将脊髓节段于正中矢状面分开,及肱三头肌,分别检测CGRP蛋白及mRNA的表达。结果神经端侧吻合后,随时间的延长,脊髓及运动终板中CGRP的表达均显著升高(P<0.01),而不做吻合的对照组中,脊髓CGRP表达维持较低水平,且呈下降趋势,但差异性不显著,运动终板中无CGRP的表达。结论提高供体神经元及运动终板中CGRP的表达可能是端侧吻合促进臂丛损伤神经再生,保护靶肌肉及其运动终板的作用机制之一。

Objective To study the expression level of CGRP in spinal cord and moter endplate after end-to-side neurorrhaphy of brachial plexus injuries in rats.Methods Sixty Wister rats were randomly divided into three groups,with 20 rats each group.The right radial nerve was repaired with end-to-side fashion after being windowed,the distal end being sutured to the epineurial window（0.2 cm×0.2 cm） 0.5 cm distal of the medial fasciculus.The left radial nerve was only windowed as control.The expression level of CGRP protein and mRNA in C4～T2 spinal segment and in brachial triceps muscle were detected 4 weeks,8 weeks,and 12 weeks postoperation respectively.Results After the end-to-side neurorrhaphy,in the test group,the expression level of CGRP in spinal cord and moter endplate were increased significantly（P〈0.01）.Significant difference was seen between the two sides.In the control group,the expression level of CGRP keeped low in spinal cord and wasn′t found in moter endplate.Conclusion Increasing the expression level of CGRP in spinal cord and moter endplate is one of its mechanisms by which the End-to-side neurorrhaphy can promote nerve regeneration of brachial plexus after injury,also protect target muscle and the moter endplate.