Grounds M D, McGeachie J K
Department of Pathology, University of Western Australia, Nedlands.
Cell Tissue Res. 1989 Feb;255(2):385-91. doi: 10.1007/BF00224122.
Muscle precursor replication in Swiss mice, in which muscle regeneration is exceptionally vigorous, was compared with previous data for regeneration in BALBc mice. The tibialis anterior muscles of 23 male and 15 female inbred Swiss SJL/J mice were crush injured, and tritiated thymidine injected into mice at various times after injury to label replicating muscle precursors. Lesion samples were taken 10 days after injury, processed for autoradiography, and grain counts of myotube nuclei analysed. Muscle regeneration was more vigorous in male compared with female Swiss mice, and in both was strikingly greater than that in BALBc mice in which there was extensive fibrous connective tissue throughout the lesions. Autoradiographic analysis showed that muscle precursor replication started at 24 hours in Swiss mice, 6 hours earlier than the onset at 30 hours in BALBc mice. Muscle precursor replication appeared to be more active 96 hours after injury in female Swiss compared with male BALBc and male Swiss mice respectively, although numbers of precursor cells replicating at other times were similar. It is not known whether the slight difference in onset of muscle precursor replication can alone account for the more complete muscle regeneration seen in Swiss mice. Similar studies were carried out in 11 male and 10 female F1 hybrid (SJL/J x BALBc) mice. Analysis of labelled myotube nuclei showed that muscle precursors did not synthesise DNA prior to 30 hours after injury, and regeneration resembled that of the parental BALBc strain.
将肌肉再生异常活跃的瑞士小鼠的肌肉前体细胞复制情况，与之前关于BALBc小鼠再生的数据进行了比较。对23只雄性和15只雌性近交瑞士SJL/J小鼠的胫前肌进行挤压损伤，并在损伤后的不同时间给小鼠注射氚标记的胸腺嘧啶核苷，以标记正在复制的肌肉前体细胞。在损伤后10天采集损伤样本，进行放射自显影处理，并分析肌管细胞核的颗粒计数。与雌性瑞士小鼠相比，雄性瑞士小鼠的肌肉再生更为活跃，且两者的肌肉再生均明显强于BALBc小鼠，后者损伤部位有大量纤维结缔组织。放射自显影分析表明，瑞士小鼠的肌肉前体细胞复制在损伤后24小时开始，比BALBc小鼠损伤后30小时的起始时间早6小时。与雄性BALBc小鼠和雄性瑞士小鼠相比，雌性瑞士小鼠在损伤后96小时时肌肉前体细胞复制似乎更为活跃，尽管在其他时间复制的前体细胞数量相似。尚不清楚肌肉前体细胞复制起始时间的细微差异是否能单独解释瑞士小鼠中更完全的肌肉再生现象。对11只雄性和10只雌性F1杂交（SJL/J×BALBc）小鼠进行了类似研究。对标记的肌管细胞核的分析表明，肌肉前体细胞在损伤后30小时之前不合成DNA，其再生情况与亲代BALBc品系相似。
