吻合血管神经的肌肉游离移植后运动终板形态的演变

Morphological changes at the motor end-plate following free muscle transfer

目的探讨吻合血管神经的肌肉游离移植后运动终板的形态演变过程及其与肌肉移植后功能降低的关系。方法建立成年Wistar大鼠股薄肌原位移植模型,用胆碱酯酶染色,连续观察术后30周内运动终板在光镜和电镜下的形态结构变化。结果在移植肌肉从失神经支配到神经再支配的过程中,运动终板的形态经历了一个动态的重建、重塑的过程,但至术后30周时仍不能恢复至对照组的精细程度。结论终板处复杂的超微结构不能完全恢复,可能是肌肉游离移植后功能削弱的重要影响因素之一。

Objective To investigate the changes at the motor end-plate （i. e. neuromuscular junction） following the free neurovascular muscle transfer. Methods Light and electron microscopy were used to study serially during 30 weeks the changes at the neuromuscular junction after free muscle transfer of the gracilis muscle in the adult Wistar rat. Results Under light microscopy ,after staining with acetyhhocholine the neuromuscular junction showed changes of degeneration with withdrawal of the innervating axon terminal followed by regeneration and reconstitution of the neuromuscular junction, With the electron microscope, mitochondrial sweelling and clumping of the synaptic vesicles were followed by withdrawal of the axon terminal from the muscle membrane on denervation. The infolding of the muscle membrane at the neuromuscular junction became less prominent. With reinnervatlon the ulatrastructure of the junction was only partially reestablishied with poorly reconstituted primary and secondary folds of the muscle membrane. The newly formed neuromuscular junction still lacked the structural detail seen in the control neuromuscular junction, even after 30 weeks.Conclusion The persistent weakness following free neurovascular muscle transfer may be attributed to the failure of full recovery of the intricate uhrastructure of the neuromuscular junction.