胚胎运动神经元移植对失神经肌肉影响的实验研究

Experimental study of the effects of embryonic motoneurons transplanted on atrophy of denervated skeletal muscle in the rat

目的 探讨胚胎运动神经元移植至入肌点前支配神经内对失神经肌肉萎缩的影响。 方法 取 2 0只健康 SD大鼠建立失神经腓肠肌动物模型 ,随机分移植组和对照组 (每组 10只 ) ;将胚胎14～ 18d的 SD鼠胚脊髓前角运动神经元的活细胞悬液注入移植组切断的胫神经远端 ,对照组注射等量的生理盐水。手术后第 3个月 ,进行腓肠肌肌力、肌湿重测定 ,组织和免疫化学检查以及胫神经纤维计数 ,并作图像分析。 结果 种植入胫神经内的鼠胚胎运动神经元能够存活。移植组腓肠肌肌力和肌湿重恢复率高于对照组 ,差异有显著性 (P<0 .0 1) ;肌纤维横截面积恢复率高于对照组 ,差异有显著性(P<0 .0 5 ) ,且 型、 型纤维面积均优于对照组 (P<0 .0 5 ) ;肌动蛋白的相对含量移植组高于对照组 ,差异有显著性 (P<0 .0 5 ) ;移植组运动终板结构清晰 ,而对照组大部分运动终板崩解 ,两组运动终板恢复率比较 ,差异有显著性 (P<0 .0 5 ) ;移植组神经纤维再生率为 0 .6 6 1± 0 .149,高于对照组的 0 .46 3±0 .10 9,差异有显著性 (P<0 .0 1)。 结论 胚胎运动神经元移植至外周神经内 ,便于靶组织获得神经营养 ,能延缓失神经肌肉的萎缩 。

Objective To explore the effects of transplanted embryonic ventral horn neurons grafted into peripheral nerve on atrophy of denervated skeletal muscle after the peripheral nerve injured Methods The model of denervated gastrocnemius was established by cutting right tibial nerves in 20SD rats, and they were divided into implanted group and control group randomly Their left side as normal control Embryonic spinal cord ventral horn neurons on rat E14th^18th days were implanted into the stump of axotomized tibial nerve in an implanted group, and the dose of saline were used in control group The myodynamia , muscle wet weight, histologic stains of bilateral gastrocnemius, and regenerated nerve fibers of axotomized tibial nerve were measured at 3rd months post operation of each rat with image pattern analysis Results In the implanted group, the rates of recovery of the gastrocnemius myodynamia, wet weight, total cross sectional areas , cross sectional areas of type Ⅰand typeⅡfibers, area of motor end plate and actin content of gastrocnemius were significantly increased compared with that of the control group( P <0 05 or P <0 01) The rates of regenerated tibial nerve fibers in implanted and control group were 0 661±0 149, 0 463±0 109 respectively,there was a significant difference ( P <0 01) Conclusions It is suggested that transplanted embryonic ventral horn neurons grafted into the injured peripheral nerve can improve the recovery morphology and function of denervated skeletal muscle, accelerate regeneration of peripheral nerve, and attenuate the atrophy of denervated skeletal muscle