Browsing by Subject "Voluntary wheel running"

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    Body Weight Influences Musculoskeletal Adaptation to Long-Term Voluntary Wheel Running During Aging
    (Oxford University Press, 2022-12-20) Kitase, Yukiko; Julian, Vallejo; Xie, Yixia; Dallas, Mark; Dallas, Sarah; Johnson, Mark; Wacker, Michael; Bonewald, Lynda; Anatomy, Cell Biology and Physiology, School of Medicine
    Frailty is a key hallmark of aging and exercise has been shown to delay aging effects. This study was initiated based on the hypothesis that voluntary wheel running (VWR) starting at 12 mo until 18 or 22 mo of age would benefit the female murine musculoskeletal system. Based on the final body weight, the mice were separated into high (HBW) and low body weight (LBW) subgroups. Beneficial effects of VWR were observed on soleus muscle mass and contractile force at both ages, although HBW led to greater increases at 22 mo. VWR increased fiber cross-sectional area by 20%, leading to more type I and fewer IIA fibers in soleus. HBW mice were resistant to age-related decline in Extensor digitorum longus (EDL) mass and contractile force. EDL in 18 mo HBW also showed 15% higher contractile force following VWR while muscle from 18 & 22 mo LBW responded to VWR with greater osteocyte protective factor secretion. Skeletal adaptation to VWR was also dependent on body weight, with HBW showing higher femoral cortical thickness and area under sedentary conditions. VWR maintained osteocyte dendrite number in HBW. VWR increased periosteal and endosteal circumferences in HBW, suggesting compensation for loss of material strength. Consistent with this, VWR maintained higher bone mechanical properties in 18mo LBW. In summary, VWR alters musculoskeletal parameters depending on body weight with HBW contributing to more muscle mass and strength to prevent sarcopenia while bone retains better mechanical properties in LBW but HBW contributes structural modification to prevent osteopenia.
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    Body weight influences musculoskeletal adaptation to long-term voluntary wheel running during aging in female mice
    (Impact Journals, 2022) Kitase, Yukiko; Vallejo, Julian A.; Dallas, Sarah L.; Xie, Yixia; Dallas, Mark; Tiede-Lewis, LeAnn; Moore, David; Meljanac, Anthony; Kumar, Corrine; Zhao, Carrie; Rosser, Jennifer; Brotto, Marco; Johnson, Mark L.; Liu, Ziyue; Wacker, Michael J.; Bonewald, Lynda; Anatomy, Cell Biology and Physiology, School of Medicine
    Frailty is the hallmark of aging that can be delayed with exercise. The present studies were initiated based on the hypothesis that long-term voluntary wheel running (VWR) in female mice from 12 to 18 or 22 months of age would have beneficial effects on the musculoskeletal system. Mice were separated into high (HBW) and low (LBW) body weight based on final body weights upon termination of experiments. Bone marrow fat was significantly higher in HBW than LBW under sedentary conditions, but not with VWR. HBW was more protective for soleus size and function than LBW under sedentary conditions, however VWR increased soleus size and function regardless of body weight. VWR plus HBW was more protective against muscle loss with aging. Similar effects of VWR plus HBW were observed with the extensor digitorum longus, EDL, however, LBW with VWR was beneficial in improving EDL fatigue resistance in 18 mo mice and was more beneficial with regards to muscle production of bone protective factors. VWR plus HBW maintained bone in aged animals. In summary, HBW had a more beneficial effect on muscle and bone with aging especially in combination with exercise. These effects were independent of bone marrow fat, suggesting that intrinsic musculoskeletal adaptions were responsible for these beneficial effects.