A basic research on muscle fiber restoration in transplanted muscle.

我们建立了一种新的大鼠面部肌肉移植模型，以检查肌肉移植与微神经血管闭塞。使用这个模型，使移植肌肉的电生理和组织学的恢复与失神经支配和自我支配的肌肉的比较。本研究使用成年雄性大鼠。分别于术后1、2、3、4、8、12、16周取5只大鼠，行肌电图检查，并取组织学标本。同时记录再神经支配肌肉的诱发电位。取移植肌横切面，HE染色，组织化学染色，光镜下观察肌球蛋白ATP酶活性。从标本中粗提肌球蛋白进行焦磷酸聚丙烯酰胺凝胶电泳。同样地，对失神经支配的股薄肌和自身支配的股薄肌进行了肌电图和组织学检查。 ...更多信息 结果表明，移植肌与自体神经支配肌的修复效果存在显著差异，提示缺血、断腱、手术侵袭等问题对移植肌的修复效果有显著影响。本实验的组织化学结果不能完全用神经调节假说来解释，但可以用Hoh等的观点来解释。的假说，表明肌纤维可能是内在的异质性，并可能是“塑料”的约束。在胎儿和新生儿发育或再生过程中观察到的“未分化”2c型纤维被认为含有EM或NM或两者。然而，发现在失神经支配、电刺激、外源性神经再支配等引起的肌纤维类型转化过程中表达的“过渡”2c型纤维含有SM和FM的混合物。因此，可能存在两种2c型纤维，尽管它们在肌球蛋白ATP酶活性方面彼此表型相同。在失神经支配期间出现EM或NM可能提示肌球蛋白亚型的去分化。少

We created a new rat model of muscle transplantation to the face in order to examine muscles transplanted with microneurovascular anastomoses. Using this model enabled comparison of restoration of transplanted muscles electrophysiologically and histologically with that of denervated and self-innervated muscles. Adult male rats were utilized in this study. At 1, 2, 3, 4, 8, 12 and 16 postoperative weeks muscle reinnervation in 5 rats was examined by EMG, followed by sacrificing the rats to obtain histological specimens. The evoked potential of the reinnervated muscle was recorded simultaneously. Transverse sections of the transplanted muscles stained by H-E and the histochemical method to demonstrate the myosin ATPase activity were examined under the light microscope. Pyrophosphate polyacrylamide gel electrophoresis of myosin crudely extracted from the specimens was performed. Similarly were examined both denervated gracilis muscles and self-innervated muscles.The EMG and histological r … More esults of our study revealed that the difference in restoration between transplanted muscle and self-innervated muscle was remarkable, indicating the prominent effects of several problems as ischemia, tenotomy, surgical invasion. The histochemical results of this experiment cannot fully be explained by the neural regulatory hypothesis, while it can be explained by Hoh et al.'s hypothesis, indicating that the muscle fibers may be intrinsically heterogenous and may be "plastic" within the constraints. The 'undifferentiated' type 2c fiber, observed during fetal and neonatal development or regeneration, is thought to contain EM or NM or both. The 'transitional' type 2c fiber, which is expressed during transformation of muscle fiber type caused by denervation, electrical stimulation, foreign-reinnervation, and so on, was, however, found to contain mixtures of SM and FM.Therefore, two kinds of type 2c fiber may exists, though they are phenotypically identical each other with regard to myosin ATPase activity. The appearance of EM or NM during denervation period may indicate possibility of dediffrentiation of myosin isoforms. Less