Morphological and biochemical evidence of muscle hyperplasia following weight-lifting exercise in rats

• DOI: 10.1152/ajpcell.1997.273.1.c246
• Publication Date: 2017-12-24T16:12:33Z
• Authors: T. Tamaki; A. Akatsuka; M. Tokunaga; K. Ishige; S. Uchiyama; T. Shiraishi
• Keywords: Creatine kinase

We used a rat model of weight lifting to examine the serial biochemical and morphological changes following muscle fiber hyperplasia during 14 days exercise. [3H]thymidine [14C]leucine labeling were determine in cellular mitotic activity level amino acid uptake myosin synthesis. Morphological assessed with light transmission electron microscopy, whereas proliferation cells was evaluated immunohistochemically 5-bromo-2'-deoxyuridine (BrdU). The intensity exercise degree damage monitored by serum creatine kinase (CK) activity. Damaged fibers sparsely distributed, significant CK leakage observed 30-60 min after Anti-BrdU-positive damaged at periphery undamaged fibers. Changes typical regeneration observed; however, formation new interstitial space also evident. changed reflected appearance anti-BrdU-positive activated satellite cells. Amino increased first week exercise, probably reflecting hypertrophy synthesis other noncontractile related proteins. second week, due hyperplasia, finding supported microscopy. Our results suggest that one bout weight-lifting untrained rats induced regeneration. process our model.