title: Skeletal muscle morphology in power-lifters with and without anabolic steroids.
abstract: The morphological appearance of the vastus lateralis (VL) muscle from high-level power-lifters on long-term anabolic steroid supplementation (PAS) and power-lifters never taking anabolic steroids (P) was compared. The effects of long- and short-term supplementation were compared. Enzyme-immunohistochemical investigations were performed to assess muscle fiber type composition, fiber area, number of myonuclei per fiber, internal myonuclei, myonuclear domains and proportion of satellite cells. The PAS group had larger type I, IIA, IIAB and IIC fiber areas (p<0.05). The number of myonuclei/fiber and the proportion of central nuclei were significantly higher in the PAS group (p<0.05). Similar results were seen in the trapezius muscle (T) but additionally, in T the proportion of fibers expressing developmental myosin isoforms was higher in the PAS group compared to the P group. Further, in VL, the PAS group had significantly larger nuclear domains in fibers containing > or = 5 myonuclei. The results of AS on VL morphology in this study were similar to previously reported short-term effects of AS on VL. The initial effects from AS appear to be maintained for several years.
authors.affiliation: Department of Integrative Medical Biology, Section for Anatomy, Umeå University, 901 87 Umeå, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Eriksson
authors.forename: Fawzi
authors.initials: F
authors.lastname: Kadi
authors.forename: Christer
authors.initials: C
authors.lastname: Malm
authors.forename: Lars-Eric
authors.initials: LE
authors.lastname: Thornell
mesh_terms: D000328:Adult; D045930:Anabolic Agents / Q000494:pharmacology*; D002467:Cell Nucleus / Q000187:drug effects / Q000473:pathology; D006801:Humans; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism; D018657:Muscle Fibers, Slow-Twitch / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009218:Myosins / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D014891:Weight Lifting
chemical_list: D045930:Anabolic Agents; D020033:Protein Isoforms; D009218:Myosins