title: Mitochondrial abnormalities are more frequent in muscles undergoing sarcopenia.
abstract: The hypothesis that the accumulation of electron transport system (ETS) abnormalities and sarcopenia are linked was investigated. Vastus lateralis, soleus, and adductor longus muscles were studied in 5-, 18-, and 36-mo-old male Fischer 344 x Brown Norway F(1) hybrid rats. A significant decrease in soleus and vastus lateralis muscle mass was observed with age. Adductor longus was resistant to muscle mass loss. Multiple serial sections were analyzed for the activities of cytochrome-c oxidase (COX) and succinate dehydrogenase (SDH). The number of fibers exhibiting a COX(-)/SDH(++) phenotype increased with age in both vastus lateralis and soleus muscles. No ETS-abnormal fibers were identified in adductor longus at any age. Cross-sectional area of ETS-abnormal fibers decreased in the abnormal region (region displaying COX(-)/SDH(++) phenotype), whereas control fibers did not. The vastus lateralis muscle, which undergoes a high degree of sarcopenia, exhibited more ETS abnormalities and associated fiber loss than the soleus and adductor longus muscles, which are more resistant to sarcopenia, suggesting a direct association between ETS abnormalities and fiber loss.
authors.affiliation: Department of Animal Health and Biomedical Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: Entela A
authors.initials: EA
authors.lastname: Bua
authors.forename: Susan H
authors.initials: SH
authors.lastname: McKiernan
authors.forename: Jonathan
authors.initials: J
authors.lastname: Wanagat
authors.forename: Debbie
authors.initials: D
authors.lastname: McKenzie
authors.forename: Judd M
authors.initials: JM
authors.lastname: Aiken
mesh_terms: D019412:Anatomy, Cross-Sectional; D000818:Animals; D001835:Body Weight; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D008297:Male; D008931:Mitochondria, Muscle / Q000378:metabolism*; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism / Q000648:ultrastructure; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D009133:Muscular Atrophy / Q000378:metabolism* / Q000473:pathology; D009929:Organ Size; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D013385:Succinate Dehydrogenase / Q000378:metabolism
chemical_list: D013385:Succinate Dehydrogenase; D003576:Electron Transport Complex IV