title: Testosterone plus low-intensity physical training in late life improves functional performance, skeletal muscle mitochondrial biogenesis, and mitochondrial quality control in male mice.
abstract: Testosterone supplementation increases muscle mass in older men but has not been shown to consistently improve physical function and activity. It has been hypothesized that physical exercise is required to induce the adaptations necessary for translation of testosterone-induced muscle mass gain into functional improvements. However, the effects of testosterone plus low intensity physical exercise training (T/PT) on functional performance and bioenergetics are unknown. In this pilot study, we tested the hypothesis that combined administration of T/PT would improve functional performance and bioenergetics in male mice late in life more than low-intensity physical training alone. 28-month old male mice were randomized to receive T/PT or vehicle plus physical training (V/PT) for 2 months. Compare to V/PT control, administration of T/PT was associated with improvements in muscle mass, grip strength, spontaneous physical movements, and respiratory activity. These changes were correlated with increased mitochondrial DNA copy number and expression of markers for mitochondrial biogenesis. Mice receiving T/PT also displayed increased expression of key elements for mitochondrial quality control, including markers for mitochondrial fission-and-fusion and mitophagy. Concurrently, mice receiving T/PT also displayed increased expression of markers for reduced tissue oxidative damage and improved muscle quality.
  
  
  CONCLUSIONS
  Testosterone administered with low-intensity physical training improves grip strength, spontaneous movements, and respiratory activity. These functional improvements were associated with increased muscle mitochondrial biogenesis and improved mitochondrial quality control.
authors.affiliation: Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America. wguo@bu.edu
authors.forename: Wen
authors.initials: W
authors.lastname: Guo
authors.forename: Siu
authors.initials: S
authors.lastname: Wong
authors.forename: Michelle
authors.initials: M
authors.lastname: Li
authors.forename: Wentao
authors.initials: W
authors.lastname: Liang
authors.forename: Marc
authors.initials: M
authors.lastname: Liesa
authors.forename: Carlo
authors.initials: C
authors.lastname: Serra
authors.forename: Ravi
authors.initials: R
authors.lastname: Jasuja
authors.forename: Andrzej
authors.initials: A
authors.lastname: Bartke
authors.forename: James L
authors.initials: JL
authors.lastname: Kirkland
authors.forename: Orian
authors.initials: O
authors.lastname: Shirihai
authors.forename: Shalender
authors.initials: S
authors.lastname: Bhasin
mesh_terms: D000375:Aging; D000818:Animals; D015444:Exercise / Q000502:physiology*; D018737:Hand Strength; D006801:Humans; D008297:Male; D051379:Mice; D008931:Mitochondria, Muscle / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D063269:Mitochondrial Turnover / Q000187:drug effects / Q000502:physiology; D009043:Motor Activity / Q000187:drug effects; D011786:Quality Control; D012119:Respiration / Q000187:drug effects; D013739:Testosterone / Q000008:administration & dosage*
chemical_list: D013739:Testosterone