Regulation of protein metabolism and muscle mass in hibernating bears: an attractive model of muscle atrophy resistance.

2016 Fiscal Year Final Research Report

• Project/Area Number: 26560369
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Sports science
• Research Institution: Health Sciences University of Hokkaido
• Principal Investigator: MIYAZAKI Mitsunori 北海道医療大学, リハビリテーション科学部, 准教授 (20632467)
• Co-Investigator(Renkei-kenkyūsha): TSUBOTA TOSHIO 北海道大学, 獣医学研究科, 教授 (10207441) ; SHIMOZURU MICHITO 北海道大学, 獣医学研究科, 准教授 (50507168)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 冬眠 / ツキノワグマ / 骨格筋 / 廃用性筋萎縮 / バイオインフォマティクス / 寝たきり

Outline of Final Research Achievements

Hibernating mammals including bears experience prolonged periods of torpor and starvation during winter survival for up to 5-6 months. Though physical inactivity and malnutrition generally lead to profound loss of muscle mass and metabolic dysfunction in human, hibernating bears show limited muscle atrophy and can successfully maintain locomotive function following hibernation. In this study, we identified that protein synthesis rate and oxidative metabolism would be enhanced in skeletal muscle of hibernating bear (Japanese black bear) through modulating intracellular signal transduction (up-regulation of mTOR-dependent signaling and down-regulation of myostatin), which then lead to limited loss of muscle mass and maintenance of physical performance.

Free Research Field

運動生理学