title: Utility of 17-(allylamino)-17-demethoxygeldanamycin treatment for skeletal muscle injury.
abstract: Repeated eccentric contractions can injure skeletal muscle and result in functional deficits that take several weeks to fully recover. The 70-kDa heat shock protein (Hsp70) is a stress-inducible molecular chaperone that maintains protein quality and plays an integral role in the muscle's repair processes following injury. Here, we attempted to hasten this recovery by pharmacologically inducing Hsp70 expression in mouse skeletal muscle with 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) (40 mg/kg) both prior to and throughout the first 7 days after an injurious bout of 150 maximal eccentric contractions. Hsp70 content in the injured skeletal muscle was strongly induced following the eccentric contractions and remained elevated over the next 7 days as the muscle underwent repair. Treatment with 17-AAG increased Hsp70 content ∼fivefold; however, this was significantly less than that induced by the injury. Moreover, 17-AAG treatment did not recover the decrements to in vivo isometric torque production following the bout of eccentric contractions. Together, these findings demonstrate that although Hsp70 content was induced in the uninjured skeletal muscle, treatment of 17-AAG (40 mg/kg) was not a preventive measure to either reduce the severity of skeletal muscle damage or enhance functional recovery following a bout of maximal eccentric contractions.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis, MN, USA. cbaumann@umn.edu.
authors.forename: Cory W
authors.initials: CW
authors.lastname: Baumann
authors.affiliation: Department of Kinesiology and Health, Georgia State University, Atlanta, GA, USA.
authors.forename: Russell G
authors.initials: RG
authors.lastname: Rogers
authors.affiliation: Department of Kinesiology and Health, Georgia State University, Atlanta, GA, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Otis
mesh_terms: D000818:Animals; D016227:Benzoquinones / Q000494:pharmacology* / Q000627:therapeutic use; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D047029:Lactams, Macrocyclic / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009119:Muscle Contraction / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000293:injuries / Q000378:metabolism; D009135:Muscular Diseases / Q000188:drug therapy / Q000473:pathology; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D016227:Benzoquinones; D018840:HSP70 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; C112765:tanespimycin
keywords: Chaperones; Damage; Eccentric contractions; Isometric torque; Mouse model