Rácz I B, Illyés G, Sarkadi L, Hamar J
National Institute of Traumatology, Semmelweis University, Medical School, Budapest, Hungary.
Eur Surg Res. 1997;29(4):254-63. doi: 10.1159/000129531.
Skeletal muscle is frequently damaged by ischemia-reperfusion both caused by direct injury and also by surgery. The purpose of the present experiments was to examine how the different types of skeletal muscles (fast and slow) react functionally and morphologically after 1 and 2 h of ischemia followed by different periods of reperfusion. The fast-twitch (musculus extensor digitorum longus, EDL) and the slow-twitch (musculus soleus, SOL) muscle of Wistar rats were prepared. They were stimulated in vivo, either directly or indirectly at different reperfusion times following tourniquet ischemia, and the contraction force of the muscles was recorded. The morphological changes were examined by light microscopy. At early reperfusion times, the contraction force of the EDL muscle was reduced by 40 and 90% after 1 and 2 h of ischemia, respectively. The contraction force was about 50% at the end of a 2-week reperfusion period in the 1-hour ischemia group and it increased significantly (from 5 to 38%) during the second week if the ischemia lasted for 2 h. Reduction of contraction force in the SOL muscle was over 50 and 90% following 1 and 2 h of ischemia, respectively, and it started to improve from the 2nd week. Morphological changes of the two types of muscle were identical. At early reperfusion times granulocytes were seen in the blood vessels adhering to the endothelium. 24 h later neutrophil granulocytes migrated into the endomysium and thereafter into the perimysium. One week after 1 h of ischemia both muscles showed normal histology. However, the structural regeneration process only started at the end of the 1st week of reperfusion after 2 h of the ischemic damage. The following conclusions can be drawn. (1) There is functional morphological evidence of ischemic and reperfusion injury in both muscles after 24 h and also after 1 week of reperfusion. (2) Functionally, the two types of muscles regenerate differently, i.e. the SOL starts to regenerate earlier than the EDL. (3) Morphologically the two types of muscle show the same reactions. An increase in the time of ischemia from 1 to 2 h delays the regeneration processes.
骨骼肌经常因直接损伤和手术导致的缺血再灌注而受损。本实验的目的是研究不同类型的骨骼肌（快肌和慢肌）在缺血1小时和2小时后，再经过不同时长的再灌注，其功能和形态上的反应。制备了Wistar大鼠的快肌（趾长伸肌，EDL）和慢肌（比目鱼肌，SOL）。在止血带缺血后的不同再灌注时间，对其进行体内直接或间接刺激，并记录肌肉的收缩力。通过光学显微镜检查形态学变化。在再灌注早期，缺血1小时和2小时后，EDL肌肉的收缩力分别降低了40%和90%。在1小时缺血组，2周再灌注期结束时收缩力约为50%；如果缺血持续2小时，在第二周收缩力显著增加（从5%增至38%）。缺血1小时和2小时后，SOL肌肉的收缩力分别降低超过50%和90%，从第二周开始收缩力开始改善。两种类型肌肉的形态学变化相同。在再灌注早期，可见血管内有粒细胞黏附于内皮。24小时后，中性粒细胞迁移至肌内膜，随后进入肌束膜。缺血1小时后1周，两块肌肉的组织学均正常。然而，在缺血损伤2小时后，结构再生过程仅在再灌注第1周结束时开始。可得出以下结论：（1）再灌注24小时和1周后，两块肌肉均有缺血再灌注损伤的功能形态学证据。（2）在功能上，两种类型的肌肉再生方式不同，即SOL比EDL更早开始再生。（3）在形态学上，两种类型的肌肉表现出相同的反应。缺血时间从1小时增加到2小时会延迟再生过程。
