title: Histomorphologic and ultrastructural recovery of myopathy in rats treated with low-level laser therapy.
abstract: The purpose of the present work was to study the effect of low-level laser therapy (LLLT): helium-neon (He-Ne) and gallium arsenide (Ga-As) laser on the histomorphology of muscle and mitochondria in experimental myopathy in rats. Thirty Suquía strain female rats were distributed in groups: (A) control (intact), (B) injured, (C) injured and treated with He-Ne laser, (D) injured and treated with Ga-As laser, (E) irradiated with He-Ne laser on the non-injured muscle, and (F) irradiated with Ga-As laser on the non-injured muscle. Myopathy was induced by injecting 0.05 mg/rat/day of adrenaline in the left gastrocnemius muscle at the same point on five consecutive days, in groups B, C, and D. LLLT was applied with 9.5 J cm-2daily for seven consecutive days in groups C, D, E, and F. The muscles were examined with optic and electronic microscopy. The inflammation was classified as absent, mild, and intense and the degree of mitochondrial alteration was graded I, II, III, and IV. Categorical data were statistically analyzed by Chi-square and the Fisher-Irwin Bilateral test, setting significant difference at p < 0.05. The damage found in muscle and mitochondria histomorphology in animals with induced myopathy (B) was intense or severe inflammation with grade III or IV of mitochondrial alteration. They underwent significant regression (p < 0.001) compared with the groups treated with He-Ne (C) and Ga-As (D) laser, in which mild or moderate inflammation was seen and mitochondrial alteration grades I and II, recovering normal myofibrillar architecture. No differences were found between the effects caused by the two lasers, or between groups A, E, and F. Group A was found to be different from B, C, and D (p < 0.001). LLLT in experimental myopathy caused significant muscular and mitochondrial morphologic recovery.
authors.affiliation: Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Santa Rosa 1085, 5000, Córdoba, Argentina.
authors.forename: Natalia
authors.initials: N
authors.lastname: Servetto
authors.affiliation: Cátedra de Patología, Carrera de Medicina, Universidad Nacional de La Rioja, De la Fuente S/N, 5300, La Rioja, Argentina.|I Cátedra de Patología, Hospital Nacional de Clínicas, Universidad Nacional de Córdoba, Santa Rosa 1564, 5000, Córdoba, Argentina.
authors.forename: David
authors.initials: D
authors.lastname: Cremonezzi
authors.affiliation: Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Santa Rosa 1085, 5000, Córdoba, Argentina.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Simes
authors.affiliation: Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Santa Rosa 1085, 5000, Córdoba, Argentina.
authors.forename: Antonio
authors.initials: A
authors.lastname: Di Pietro
authors.affiliation: Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Santa Rosa 1085, 5000, Córdoba, Argentina. campanav@hotmail.com.|Cátedra de Física Biomédica, Carrera de Medicina, Universidad Nacional de La Rioja, De la Fuente S/N, 5300, La Rioja, Argentina. campanav@hotmail.com.
authors.forename: Vilma R
authors.initials: VR
authors.lastname: Campana
mesh_terms: D000818:Animals; D005260:Female; D054020:Lasers, Gas; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000473:pathology* / Q000648:ultrastructure*; D054792:Muscle, Striated / Q000473:pathology / Q000648:ultrastructure; D009135:Muscular Diseases / Q000473:pathology* / Q000532:radiotherapy*; D051381:Rats
keywords: Gallium-arsenide laser; Helium-neon laser; Inflammation; LLLT; Mitochondria; Myopathy