Heat‐Stress effects on the myosin heavy chain phenotype of rat soleus fibers during the early stages of regeneration. Issue 6 (1st June 2015)

• Record Type: Journal Article
• Authors: Oishi, Yasuharu; Roy, Roland R.; Ogata, Tomonori; Ohira, Yoshinobu
• Is Part Of: Muscle & nerve. Volume 52:Issue 6(2015:Dec.)
• Page Start: 1047
• Page End: 1056
• Publication Date: 2015-06-01
• Subjects: fiber regeneration -- heat stress -- myosin heavy chain -- rat soleus -- satellite cell; Neuromuscular diseases -- Periodicals; Muscles -- Periodicals; Nerves -- Periodicals; 616.74
• DOI: 10.1002/mus.24686
• Languages: English
• ISSNs: 0148-639X

Abstract

ABSTRACT: Introduction: We investigated heat‐stress effects on the adult myosin heavy chain (MyHC) profile of soleus muscle fibers at an early stage of regeneration. Methods: Regenerating fibers in adult rats were analyzed 2, 4, or 6 days after bupivacaine injection. Rats were heat stressed by immersion in water (42 ± 1°C) for 30 minutes 24 hours after bupivacaine injection and every other day thereafter. Results: No adult MyHC isoforms were observed after 2 days, whereas some fibers expressed only fast MyHC after 4 days. Heat stress increased fast and slow MyHC in regenerating fibers after 6 days. Regenerating fibers expressing only slow MyHC were observed only in heat‐stressed muscles. Bupivacaine injection increased the number of Pax7 + and MyoD + satellite cells in regenerating fibers, more so in heat‐stressed rats. Conclusion: The results indicate that heat stress accelerates fast‐to‐slow MyHC phenotype conversion in regenerating fibers via activation of satellite cells. Muscle Nerve 52 : 1047–1056, 2015