Effects of resistance training on the rate of muscle protein synthesis in frail elderly people.
Advancing age is associated with a reduction in skeletal muscle protein, muscle strength, muscle quality, and chemical modifications that may impair protein function. Sarcopenia has been coupled with physical disability, frailty, and a loss of independent function. Using stable isotope tracer methodologies and mass spectrometric detection, we observed: (a) 76-92-year-old physically frail and 62-74-year-old middle-age adults have lower mixed muscle protein synthetic rates than 20-32-year-old men and women; (b) 2 weeks and 3 months of weightlifting exercise increased the synthetic rate of myosin heavy chain (MHC) and mixed muscle proteins to a similar magnitude in frail, middle-age, and young women and men; (c) Serum myostatin-immunoreactive protein levels were elevated in physically frail women and were inversely correlated with lean mass. This suggests that the protein synthetic machinery adapts rapidly to increased contractile activity and that the adaptive response(s) are maintained even in frail elders.
Schulte
J N
JN
Division of Metabolism, Endocrinology, and Diabetes, Washington University School of Medicine, St. Louis, MO 63110, USA.
Yarasheski
K E
KE
D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism* / Q000502:physiology; D005260:Female; D016330:Frail Elderly; D006801:Humans; D007553:Isotope Labeling; D007700:Kinetics; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D009124:Muscle Proteins / Q000096:biosynthesis*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000378:metabolism* / Q000502:physiology; D018995:Myosin Heavy Chains / Q000096:biosynthesis; D013997:Time Factors; D014891:Weight Lifting / Q000502:physiology*
D009124:Muscle Proteins; D018995:Myosin Heavy Chains