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Short-term muscle disuse induces a rapid and sustained decline in daily myofibrillar protein synthesis rates.
- Source :
-
American journal of physiology. Endocrinology and metabolism [Am J Physiol Endocrinol Metab] 2020 Feb 01; Vol. 318 (2), pp. E117-E130. Date of Electronic Publication: 2019 Nov 19. - Publication Year :
- 2020
-
Abstract
- Short-term muscle disuse has been reported to lower both postabsorptive and postprandial myofibrillar protein synthesis rates. This study assessed the impact of disuse on daily myofibrillar protein synthesis rates following short-term (2 and 7 days) muscle disuse under free living conditions. Thirteen healthy young men (age: 20 ± 1 yr; BMI: 23 ± 1 kg/m <superscript>-2</superscript> ) underwent 7 days of unilateral leg immobilization via a knee brace, with the nonimmobilized leg acting as a control. Four days before immobilization participants ingested 400 mL of 70% deuterated water, with 50-mL doses consumed daily thereafter. Upper leg bilateral MRI scans and muscle biopsies were collected before and after 2 and 7 days of immobilization to determine quadriceps volume and daily myofibrillar protein synthesis rates. Immobilization reduced quadriceps volume in the immobilized leg by 1.7 ± 0.3 and 6.7 ± 0.6% after 2 and 7 days, respectively, with no changes in the control leg. Over the 1-wk immobilization period, myofibrillar protein synthesis rates were 36 ± 4% lower in the immobilized (0.81 ± 0.04%/day) compared with the control (1.26 ± 0.04%/day) leg ( P < 0.001). Myofibrillar protein synthesis rates in the control leg did not change over time ( P = 0.775), but in the immobilized leg they were numerically lower during the 0- to 2-day period (16 ± 6%, 1.11 ± 0.09%/day, P = 0.153) and were significantly lower during the 2- to 7-day period (44 ± 5%, 0.70 ± 0.06%/day, P < 0.001) when compared with the control leg. We conclude that 1 wk of muscle disuse induces a rapid and sustained decline in daily myofibrillar protein synthesis rates in healthy young men.
- Subjects :
- Body Water metabolism
Diet
Exercise
Gene Expression
Healthy Volunteers
Humans
Immobilization
Kinetics
Leg
Magnetic Resonance Imaging
Male
Muscle Proteins genetics
Muscle Strength
Muscle, Skeletal diagnostic imaging
Muscular Atrophy diagnostic imaging
Quadriceps Muscle diagnostic imaging
Quadriceps Muscle metabolism
Young Adult
Muscle Proteins biosynthesis
Muscle, Skeletal metabolism
Muscular Atrophy metabolism
Myofibrils metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1522-1555
- Volume :
- 318
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Endocrinology and metabolism
- Publication Type :
- Academic Journal
- Accession number :
- 31743039
- Full Text :
- https://doi.org/10.1152/ajpendo.00360.2019