OBJECTIVE: To compare the single-fiber characteristics and muscle weakness of persons with multiple sclerosis (MS) with that of healthy persons without MS. DESIGN: Descriptive. SETTING: A university-based exercise physiology laboratory. PARTICIPANTS: Fourteen subjects (7 controls, 7 people with relapsing-remitting MS; Expanded Disability Status Scale median score, 6.0; range, 2.5-6.5). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Singe muscle fiber myosin heavy chain (MHC) distribution, myosin adenosine triphosphatase fiber type, and single muscle fiber cross-sectional area (CSA). RESULTS: The distribution of MHC I, MHC IIa, MHC IIx, and total hybrid fibers (I/IIa+I/IIa/IIx+IIa/IIx) did not differ between the 2 groups. However, the distribution of MHC I/IIa/IIx fibers was greater ( P <.040) in the MS group (MS: 6% vs controls: 2%). MS subjects also had a greater proportion ( P <.002) of MHC IIx-dominant IIa/IIx fibers (MS: 46% vs controls: 13%). Single-fiber CSA and fiber type, for all fiber types, did not differ between groups. CONCLUSIONS: These data suggest that, in general, moderately impaired MS subjects with documented muscle weakness have similar MHC and fiber-type characteristics as age-matched sedentary controls. The data indicate that the quality of skeletal muscle, with regard to MHC distribution, is unaffected by MS.
OBJECTIVE: To compare the single-fiber characteristics and muscle weakness of persons with multiple sclerosis (MS) with that of healthy persons without MS. DESIGN: Descriptive. SETTING: A university-based exercise physiology laboratory. PARTICIPANTS: Fourteen subjects (7 controls, 7 people with relapsing-remitting MS; Expanded Disability Status Scale median score, 6.0; range, 2.5-6.5). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Singe muscle fiber myosin heavy chain (MHC) distribution, myosin adenosine triphosphatase fiber type, and single muscle fiber cross-sectional area (CSA). RESULTS: The distribution of MHC I, MHC IIa, MHC IIx, and total hybrid fibers (I/IIa+I/IIa/IIx+IIa/IIx) did not differ between the 2 groups. However, the distribution of MHC I/IIa/IIx fibers was greater ( P <.040) in the MS group (MS: 6% vs controls: 2%). MS subjects also had a greater proportion ( P <.002) of MHC IIx-dominant IIa/IIx fibers (MS: 46% vs controls: 13%). Single-fiber CSA and fiber type, for all fiber types, did not differ between groups. CONCLUSIONS: These data suggest that, in general, moderately impaired MS subjects with documented muscle weakness have similar MHC and fiber-type characteristics as age-matched sedentary controls. The data indicate that the quality of skeletal muscle, with regard to MHC distribution, is unaffected by MS.
Authors: Michael A Trevino; Hannah L Dimmick; Mandy E Parra; Adam J Sterczala; Jonathan D Miller; Jake A Deckert; Philip M Gallagher; Andrew C Fry; Joseph P Weir; Trent J Herda Journal: Exp Brain Res Date: 2022-01-20 Impact factor: 1.972
Authors: Kevin A Murach; Cory M Dungan; Kate Kosmac; Thomas B Voigt; Timothy W Tourville; Mark S Miller; Marcas M Bamman; Charlotte A Peterson; Michael J Toth Journal: J Appl Physiol (1985) Date: 2019-11-07
Authors: Anja Mähler; Jochen Steiniger; Markus Bock; Alexander U Brandt; Verena Haas; Michael Boschmann; Friedemann Paul Journal: PLoS One Date: 2012-08-28 Impact factor: 3.240