title: The expression of androgen receptors in human neck and limb muscles: effects of training and self-administration of androgenic-anabolic steroids.
abstract: The purpose of this study was to investigate the immunohistochemical expression of androgen receptors (AR) in human vastus lateralis and trapezius muscles and to determine whether long-term strength training and self-administration of androgenic-anabolic steroids are accompanied by changes in AR content. Biopsy samples were taken from eight high-level power-lifters (P), nine high-level power-lifters who used anabolic steroids (PAS) and six untrained subjects (U). Myonuclei and AR were visualised in cross-sections stained with the monoclonal antibody against AR and 4',6-diamidino-2-phenylindole. The proportion of AR-containing myonuclei per fibre cross-section was higher in the trapezius than in the vastus lateralis (P<0.05). In the trapezius, the proportion of AR-containing myonuclei was higher in P compared to U and in PAS compared to both P and U (P<0. 05). On the contrary, in the vastus lateralis, there were no differences in AR content between the three groups. Myonuclear number in both muscles was higher in P compared to U and in PAS compared to both P and U (P<0.05). In conclusion, AR content differs greatly between human neck and limb muscles. Moreover, the regulation of AR-containing myonuclei following training and self-administration of androgenic-anabolic steroids is muscle dependent.
authors.affiliation: Department of Integrative Medical Biology, Section for Anatomy, Umeå University, 901 87, Umeå, Sweden. fawzi.kadi@anatomy.umu.se
authors.forename: F
authors.initials: F
authors.lastname: Kadi
authors.forename: P
authors.initials: P
authors.lastname: Bonnerud
authors.forename: A
authors.initials: A
authors.lastname: Eriksson
authors.forename: L E
authors.initials: LE
authors.lastname: Thornell
mesh_terms: D000328:Adult; D045930:Anabolic Agents / Q000008:administration & dosage*; D002467:Cell Nucleus / Q000378:metabolism; D006801:Humans; D007866:Leg; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D009334:Neck Muscles / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D011944:Receptors, Androgen / Q000096:biosynthesis*; D012651:Self Medication; D045165:Testosterone Congeners / Q000008:administration & dosage*; D014891:Weight Lifting / Q000502:physiology*
chemical_list: D045930:Anabolic Agents; D011944:Receptors, Androgen; D045165:Testosterone Congeners