title: Skeletal muscle findings in experimental autoimmune encephalomyelitis.
abstract: BACKGROUND
  Skeletal muscle is a target organ in multiple sclerosis, a chronic debilitating disease of the central nervous system caused by demyelination and axonal deterioration. Since the experimental autoimmune encephalomyelitis model reproduces the relapsing-remitting course found in most multiple sclerosis patients, this model was used to compare the histological features of skeletal muscle at onset with those observed at the start of the second relapse.
  
  
  METHODS
  Histological, histochemical and ultrastructural changes, as well as biochemical oxidative damage and antioxidant-system markers, were examined in the soleus and extensor digitorum longus muscles of Dark Agouti rats in which experimental autoimmune encephalomyelitis had been induced by active immunization using myelin oligodendrocyte glycoprotein.
  
  
  RESULTS
  Histological examination at disease onset revealed ragged-red fibers and ultrastructural evidence of mitochondrial degeneration. At the second relapse, neurogenic changes included a wide range of cytoarchitectural lesions, skeletal muscle atrophy and the appearance of intermediate fibers; however, differences were observed between soleus and extensor digitorum longus lesions. Biochemical tests disclosed an increase in oxidative stress markers at onset, which was more pronounced at the second relapse.
  
  
  CONCLUSIONS
  Microscopic findings suggest that two patterns can be distinguished at disease onset: an initial phase characterized by muscle mitochondrial alterations, and a second phase dominated by a histological muscle pattern of clearly neurogenic origin.
authors.affiliation: Departamento de Ciencias Morfológicas (Sección de Histología), Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Spain.
authors.forename: Evelio
authors.initials: E
authors.lastname: Luque
authors.affiliation: Departamento de Ciencias Morfológicas (Sección de Histología), Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Ruz-Caracuel
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Medina
authors.affiliation: Departamento de Ciencias Morfológicas (Sección de Histología), Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Leiva-Cepas
authors.affiliation: Unidad de Gestión Clínica de Neurología, Hospital Universitario Reina Sofía, Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Agüera
authors.affiliation: Unidad de Gestión Clínica de Neurología, Hospital Universitario Reina Sofía, Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Sánchez-López
authors.affiliation: Departamento de Ciencias Sociosanitarias, Radiología y Medicina Física (Sección de Psiquiatría), Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Lillo
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain.
authors.forename: Macarena
authors.initials: M
authors.lastname: Aguilar-Luque
authors.affiliation: Departamento de Ciencias Morfológicas (Sección de Histología), Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Jimena
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Spain.
authors.forename: Isaac
authors.initials: I
authors.lastname: Túnez
authors.affiliation: Departamento de Ciencias Morfológicas (Sección de Histología), Facultad de Medicina y Enfermería, Universidad de Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Spain. Electronic address: cm1peamj@uco.es.
authors.forename: José
authors.initials: J
authors.lastname: Peña
mesh_terms: D000818:Animals; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D046529:Microscopy, Electron, Transmission; D018482:Muscle, Skeletal / Q000378:metabolism / Q000648:ultrastructure*; D018384:Oxidative Stress / Q000502:physiology; D051381:Rats
keywords: Experimental autoimmune encephalomyelitis; Mitochondria; Multiple sclerosis; Ragged-red fibers; Skeletal muscle