title: Heat-Stress effects on the myosin heavy chain phenotype of rat soleus fibers during the early stages of regeneration.
abstract: BACKGROUND
  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.
  
  
  CONCLUSIONS
  The results indicate that heat stress accelerates fast-to-slow MyHC phenotype conversion in regenerating fibers via activation of satellite cells.
authors.affiliation: Laboratory of Muscle Physiology, Faculty of Education, Kumamoto University, Kumamoto, 860-8555, Japan.
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Oishi
authors.affiliation: Department of Integrative Biology and Physiology and Brain Research Institute, University of California Los Angeles, Los Angeles, California, USA.
authors.forename: Roland R
authors.initials: RR
authors.lastname: Roy
authors.affiliation: Faculty of Human Environmental Studies, Hiroshima-Shudo University, Hiroshima, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Ogata
authors.affiliation: Research Center for Adipocyte & Muscle Science, Doshisha University, Kyotanabe City, Kyoto, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Ohira
mesh_terms: D000779:Anesthetics, Local / Q000627:therapeutic use; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002045:Bupivacaine / Q000627:therapeutic use; D002452:Cell Count; D004195:Disease Models, Animal; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism; D018882:Heat Stress Disorders / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D017570:MyoD Protein / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000378:metabolism*; D015513:Oncogene Proteins / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D051761:Paired Box Transcription Factors / Q000378:metabolism; D010641:Phenotype; D020033:Protein Isoforms; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000187:drug effects / Q000502:physiology*; D032496:Satellite Cells, Skeletal Muscle / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D013997:Time Factors
chemical_list: D000779:Anesthetics, Local; D050884:HSP72 Heat-Shock Proteins; D017570:MyoD Protein; D015513:Oncogene Proteins; C530821:PAX7 protein, rat; D051761:Paired Box Transcription Factors; D020033:Protein Isoforms; D018995:Myosin Heavy Chains; D002045:Bupivacaine
keywords: fiber regeneration; heat stress; myosin heavy chain; rat soleus; satellite cell