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，以检查微神经血管吻合移植的肌肉。使用该模型可以将移植肌肉的电生理和组织学恢复与失神经和自主神经支配的肌肉进行比较。本研究采用成年雄性大鼠。分别于术后1、2、3、4、8、12、16周对5只大鼠进行肌电检查，然后处死动物，取组织标本。同时记录神经支配肌肉的诱发电位。移植肌行H-E染色和肌球蛋白ATPase活性组织化学染色，光镜下观察。对从标本中提取的肌球蛋白进行焦磷酸盐-聚丙烯酰胺凝胶电泳法。同样地，对失神经支配的股薄肌和自主神经支配的肌肉进行了检查。EMG和组织学r…更多的研究结果表明，移植肌肉与自体神经支配的肌肉修复效果差异显著，提示缺血、肌腱切断、手术侵袭等问题效果显著。这项实验的组织化学结果不能完全用神经调节假说来解释，而可以用Hoh等人的S假说来解释。该假说表明，肌肉纤维可能是内在的异质性的，在限制条件下可能是“可塑性的”。在胎儿和新生儿发育或再生过程中观察到的“未分化”的2c型纤维，被认为含有EM或NM，或者两者都含有。然而，在失神经、电刺激、异体神经再支配等引起的肌肉纤维类型转变过程中表达的过渡型2c纤维，被发现含有SM和FM的混合物。因此，可能存在两种2c型纤维，尽管它们在表型上是相同的肌球蛋白ATPase活性。在去神经期出现EM或NM可能提示肌球蛋白亚型去分化的可能性。较少

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