| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
E-mail contact: evolpi{at}utmb.edu
A reduced response of older skeletal muscle to anabolic stimuli may contribute to the development of sarcopenia. We hypothesized that muscle proteins are resistant to the anabolic action of insulin in the elderly. We examined the effects of hyperinsulinemia on muscle protein metabolism in young (25±2 year) and older (68±1 year) healthy subjects using stable isotope tracer techniques. Leg blood flow was higher in the young at baseline and increased during hyperinsulinemia, whereas it did not change in the elderly. Glucose concentrations and muscle uptake were not different between groups at baseline and during hyperinsulinemia. Leg phenylalanine net balance was not different at baseline and significantly increased in both groups with hyperinsulinemia (P<0.05) but to a greater extent in the young (P<0.05). Muscle protein synthesis increased only in the young during hyperinsulinemia. Muscle protein breakdown did not significantly change in either group, although it tended to decrease in the elderly. Changes in muscle protein synthesis were correlated with changes in leg amino acid delivery (R=0.89; P=0.0001) and blood flow (R=0.90; P<0.0001). In conclusion, skeletal muscle protein synthesis is resistant to the anabolic action of insulin in older subjects, which may be an important contributor to the development of sarcopenia.
Key words: skeletal muscle • hyperinsulinemia • leg blood flow • phenylalanine
This article has been cited by other articles:
|
|
 |
|
  G. I. Smith, D. T. Villareal, C. P. Lambert, D. N. Reeds, B. S. Mohammed, and B. Mittendorfer Timing of the initial muscle biopsy does not affect the measured muscle protein fractional synthesis rate during basal, postabsorptive conditions J Appl Physiol, February 1, 2010; 108(2): 363 - 368. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. L. Mayhew, J.-s. Kim, J. M. Cross, A. A. Ferrando, and M. M. Bamman Translational signaling responses preceding resistance training-mediated myofiber hypertrophy in young and old humans J Appl Physiol, November 1, 2009; 107(5): 1655 - 1662. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. A Wilkes, A. L Selby, P. J Atherton, R. Patel, D. Rankin, K. Smith, and M. J Rennie Blunting of insulin inhibition of proteolysis in legs of older subjects may contribute to age-related sarcopenia Am. J. Clinical Nutrition, November 1, 2009; 90(5): 1343 - 1350. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Koopman, N. Crombach, A. P Gijsen, S. Walrand, J. Fauquant, A. K Kies, S. Lemosquet, W. H. Saris, Y. Boirie, and L. J. van Loon Ingestion of a protein hydrolysate is accompanied by an accelerated in vivo digestion and absorption rate when compared with its intact protein Am. J. Clinical Nutrition, July 1, 2009; 90(1): 106 - 115. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Koopman and L. J. C. van Loon Aging, exercise, and muscle protein metabolism J Appl Physiol, June 1, 2009; 106(6): 2040 - 2048. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Fujita, H. C. Dreyer, M. J. Drummond, E. L. Glynn, E. Volpi, and B. B. Rasmussen Essential amino acid and carbohydrate ingestion before resistance exercise does not enhance postexercise muscle protein synthesis J Appl Physiol, May 1, 2009; 106(5): 1730 - 1739. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. L. Dillon, M. Sheffield-Moore, D. Paddon-Jones, C. Gilkison, A. P. Sanford, S. L. Casperson, J. Jiang, D. L. Chinkes, and R. J. Urban Amino Acid Supplementation Increases Lean Body Mass, Basal Muscle Protein Synthesis, and Insulin-Like Growth Factor-I Expression in Older Women J. Clin. Endocrinol. Metab., May 1, 2009; 94(5): 1630 - 1637. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. C. Henderson, K. Dhatariya, G. C. Ford, K. A. Klaus, R. Basu, R. A. Rizza, M. D. Jensen, S. Khosla, P. O'Brien, and K. S. Nair Higher muscle protein synthesis in women than men across the lifespan, and failure of androgen administration to amend age-related decrements FASEB J, February 1, 2009; 23(2): 631 - 641. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Volpi, D. L. Chinkes, and B. B. Rasmussen Sequential muscle biopsies during a 6-h tracer infusion do not affect human mixed muscle protein synthesis and muscle phenylalanine kinetics Am J Physiol Endocrinol Metab, October 1, 2008; 295(4): E959 - E963. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. L. Greenhaff, L. G. Karagounis, N. Peirce, E. J. Simpson, M. Hazell, R. Layfield, H. Wackerhage, K. Smith, P. Atherton, A. Selby, et al. Disassociation between the effects of amino acids and insulin on signaling, ubiquitin ligases, and protein turnover in human muscle Am J Physiol Endocrinol Metab, September 1, 2008; 295(3): E595 - E604. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. J. Colman, T. M. Beasley, D. B. Allison, and R. Weindruch Attenuation of Sarcopenia by Dietary Restriction in Rhesus Monkeys J Gerontol A Biol Sci Med Sci, June 1, 2008; 63(6): 556 - 559. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. J. Manders, R. Koopman, M. Beelen, A. P. Gijsen, W. K. Wodzig, W. H. Saris, and L. J. van Loon The Muscle Protein Synthetic Response to Carbohydrate and Protein Ingestion Is Not Impaired in Men with Longstanding Type 2 Diabetes J. Nutr., June 1, 2008; 138(6): 1079 - 1085. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Paddon-Jones, K. R Short, W. W Campbell, E. Volpi, and R. R Wolfe Role of dietary protein in the sarcopenia of aging Am. J. Clinical Nutrition, May 1, 2008; 87(5): 1562S - 1566S. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A.A. Sayer, H.E. Syddall, E.M. Dennison, H.J. Martin, D.I.W. Phillips, C. Cooper, and C.D. Byrne Grip strength and the metabolic syndrome: findings from the Hertfordshire Cohort Study QJM, November 1, 2007; 100(11): 707 - 713. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Fujita, H. C. Dreyer, M. J. Drummond, E. L. Glynn, J. G. Cadenas, F. Yoshizawa, E. Volpi, and B. B. Rasmussen Nutrient signalling in the regulation of human muscle protein synthesis J. Physiol., July 15, 2007; 582(2): 813 - 823. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Fujita, B. B. Rasmussen, J. G. Cadenas, M. J. Drummond, E. L. Glynn, F. R. Sattler, and E. Volpi Aerobic Exercise Overcomes the Age-Related Insulin Resistance of Muscle Protein Metabolism by Improving Endothelial Function and Akt/Mammalian Target of Rapamycin Signaling Diabetes, June 1, 2007; 56(6): 1615 - 1622. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Schrager, E. J. Metter, E. Simonsick, A. Ble, S. Bandinelli, F. Lauretani, and L. Ferrucci Sarcopenic obesity and inflammation in the InCHIANTI study J Appl Physiol, March 1, 2007; 102(3): 919 - 925. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Fujita, B. B. Rasmussen, J. A. Bell, J. G. Cadenas, and E. Volpi Basal muscle intracellular amino acid kinetics in women and men Am J Physiol Endocrinol Metab, January 1, 2007; 292(1): E77 - E83. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. R Wolfe The underappreciated role of muscle in health and disease. Am. J. Clinical Nutrition, September 1, 2006; 84(3): 475 - 482. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
