title: Voluntary Aerobic Exercise Reverses Frailty in Old Mice.
abstract: Frailty is a major cause of disability and loss of independence in the elderly. Using clinically relevant criteria from our previously established mouse frailty index, we investigated the effects of aerobic exercise on frailty in male C57BL/6 mice. In order to measure the effect of treatment on the individual animals, we constructed a composite score, the Frailty Intervention Assessment Value. We hypothesized voluntary aerobic exercise would improve individual criteria and reverse or prevent frailty in the old mice. Five adult and 11 old mice (6 and 28+ months, respectively) were housed individually in cages with running wheels for 4 weeks. Controls (adult, n = 5 and old, n = 17) were housed without wheels. Inverted cling grip and rotarod tests were performed pre- and postintervention. Hind limb muscles were used for biochemical analysis and contractility experiments. We conclude that the exercise stimulus reversed frailty and was sufficient to maintain or improve functional performance in old mice, as well as to produce measurable morphological changes. In addition, the Frailty Intervention Assessment Value proved to be a valuable tool with increased power to detect treatment effects and to examine the intervention efficacy at the level of the individual mouse.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis.
authors.forename: Ted G
authors.initials: TG
authors.lastname: Graber
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis.
authors.forename: Lisa
authors.initials: L
authors.lastname: Ferguson-Stegall
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis.
authors.forename: Haiming
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis. thomp067@umn.edu.
authors.forename: LaDora V
authors.initials: LV
authors.lastname: Thompson
mesh_terms: D000375:Aging; D000818:Animals; D005552:Forelimb; D006614:Hindlimb; D008297:Male; D008810:Mice, Inbred C57BL; D009119:Muscle Contraction; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D018995:Myosin Heavy Chains / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010805:Physical Conditioning, Animal; D010807:Physical Endurance; D020033:Protein Isoforms / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C485290:Ppargc1a protein, mouse; D020033:Protein Isoforms; D014157:Transcription Factors; D018995:Myosin Heavy Chains
keywords: Aerobic; Exercise; Frailty; Mice; Voluntary wheel running