title: Role of alpha-actin in muscle damage of injured athletes in comparison with traditional markers.
abstract: OBJECTIVE
  In order to identify a reliable marker for the early detection of muscle injuries in sports, alpha-actin protein and other markers of muscle damage were studied in sera of uninjured sportspeople and those with skeletal muscle injury.
  
  
  METHODS
  Blood samples were obtained from 20 sportspeople with skeletal muscle injury and 48 uninjured sportspeople. Immunoassays were performed to determine cardiac troponin I (TnI), troponin T, lactate dehydrogenase and myoglobin concentrations. Western blot and densitometry were used to measure alpha-actin concentrations. Skeletal muscle damage was diagnosed according to physical examination, MRI findings and the biochemical criterion of a creatine kinase value >500 IU/l (Rosalki method, Beckman Instruments SL, Fullerton, California, USA). Results were also compared with previously obtained data on injured and uninjured non-sportspeople.
  
  
  RESULTS
  The mean serum concentration of alpha-actin was significantly higher in sportspeople with muscle damage (10.49 microg/ml) than in uninjured sportspeople (3.99 mcirog/ml). Sera from injured sportspeople showed higher levels of alpha-actin than of troponin or myoglobin. No significant difference in TnI levels was observed between the groups.
  
  
  CONCLUSIONS
  According to these results, alpha-actin is a new and reliable marker of skeletal muscle damage in sportspeople which can be used for the detection of muscle injury. Possible cross interference between skeletal and cardiac muscle damage can be discriminated by the combined use of alpha-actin and TnI. These data suggest that early measurement of alpha-actin in sportspeople with suspected muscle damage will allow them to receive earlier and more effective treatment and to return sooner to the practice of their sport.
authors.affiliation: Department of Health Sciences, University of Jaén, Jaén, Spain. amat103@ugr.es
authors.forename: Antonio
authors.initials: A
authors.lastname: Martínez Amat
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Marchal Corrales
authors.forename: Fernando
authors.initials: F
authors.lastname: Rodríguez Serrano
authors.forename: Houria
authors.initials: H
authors.lastname: Boulaiz
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Prados Salazar
authors.forename: Fidel
authors.initials: F
authors.lastname: Hita Contreras
authors.forename: Octavio
authors.initials: O
authors.lastname: Caba Perez
authors.forename: Esmeralda
authors.initials: E
authors.lastname: Carrillo Delgado
authors.forename: Ignacio
authors.initials: I
authors.lastname: Martín
authors.forename: Antonia
authors.initials: A
authors.lastname: Aranega Jimenez
mesh_terms: D000199:Actins / Q000097:blood*; D000328:Adult; D001265:Athletic Injuries / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000293:injuries*; D009135:Muscular Diseases / Q000097:blood*; D009211:Myoglobin / Q000097:blood; D012680:Sensitivity and Specificity; D014336:Troponin / Q000097:blood
chemical_list: D000199:Actins; D015415:Biomarkers; D009211:Myoglobin; D014336:Troponin; D003402:Creatine Kinase