Skeletal muscle regeneration in young rats

✍ Scribed by Walker, Bruce E.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1972
• Tongue: English
• Weight: 731 KB
• Volume: 133
• Category: Article
• ISSN: 0002-9106
• DOI: 10.1002/aja.1001330310

✦ Synopsis

The source of myotube nuclei in regeneration of skeletal muscle in young rats was studied by comparing frequencies of labeled nuclei in two experiments. In a single injury experiment, multiple injections of thymidine-H3 were given during a three day period, skeletal muscle was injured 12 days later and the rats were killed four days after injury. There were almost no labeled myotube nuclei in this experiment. In a double injury experiment, thymidine-H3 was injected two days after injury, the muscle was reinjured 12 days later, and the rats were killed four days after the second injury. Half of the myotube nuclei were radioactive and most of the centrally placed nuclei in maturing muscle fibers from the initial injury were radioactive. Since nuclei at the periphery of muscle fibers, including satellite cell nuclei, would have been labeled in both experiments, whereas myonuclei were extensively labeled only in the double injury experiment, it was concluded that the myotube nuclei were derived mainly from myonuclei.