E Volpi

Summary

Affiliation: University of Southern California
Country: USA

Publications

  1. ncbi Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults
    Elena Volpi
    Department of Internal Medicine, University of Texas Medical Branch, Galveston, USA
    Am J Clin Nutr 78:250-8. 2003
  2. ncbi Basal muscle amino acid kinetics and protein synthesis in healthy young and older men
    E Volpi
    Division of Endocrinology and Diabetes, University of Southern California, 1333 San Pablo St, BMT B11, Los Angeles, CA 90033, USA
    JAMA 286:1206-12. 2001
  3. ncbi Muscle tissue changes with aging
    Elena Volpi
    Division of Endocrinology and Diabetes, Department of Medicine, University of Southern California, Los Angeles, California, USA
    Curr Opin Clin Nutr Metab Care 7:405-10. 2004
  4. ncbi Supraphysiological hyperinsulinaemia is necessary to stimulate skeletal muscle protein anabolism in older adults: evidence of a true age-related insulin resistance of muscle protein metabolism
    S Fujita
    Sealy Center on Aging, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555 0460, USA
    Diabetologia 52:1889-98. 2009
  5. ncbi Resistance exercise increases leg muscle protein synthesis and mTOR signalling independent of sex
    H C Dreyer
    Division of Rehabilitation Sciences, Department of Physical Therapy, University of Texas Medical Branch, Galveston, TX 77555, USA
    Acta Physiol (Oxf) 199:71-81. 2010
  6. ncbi Whole body and skeletal muscle glutamine metabolism in healthy subjects
    B Mittendorfer
    Department of Surgery, University of Texas Medical Branch at Galveston, Galveston, TX 77550, USA
    Am J Physiol Endocrinol Metab 280:E323-33. 2001
  7. ncbi Insulin resistance of muscle protein metabolism in aging
    Blake B Rasmussen
    Department of Kinesiology, University of Southern California, Los Angeles, California, USA
    FASEB J 20:768-9. 2006
  8. ncbi Measurement of skin protein breakdown in a rat model
    E Volpi
    Department of Internal Medicine, University of Texas Medical Branch, Galveston, 77555, USA
    Am J Physiol Endocrinol Metab 279:E900-6. 2000
  9. ncbi Oral and intravenously administered amino acids produce similar effects on muscle protein synthesis in the elderly
    B B Rasmussen
    University of Southern California, Department of Kinesiology, University Park Campus, 3560 Watt Way, PED 107, Los Angeles, CA 90089 0652, USA
    J Nutr Health Aging 6:358-62. 2002
  10. ncbi Skeletal muscle protein anabolic response to resistance exercise and essential amino acids is delayed with aging
    Micah J Drummond
    Department of Physical Therapy, Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555 1144, USA
    J Appl Physiol 104:1452-61. 2008

Collaborators

Detail Information

Publications44

  1. ncbi Essential amino acids are primarily responsible for the amino acid stimulation of muscle protein anabolism in healthy elderly adults
    Elena Volpi
    Department of Internal Medicine, University of Texas Medical Branch, Galveston, USA
    Am J Clin Nutr 78:250-8. 2003
    ..We have shown that balanced amino acids stimulate muscle protein anabolism in the elderly, but it is unknown whether all amino acids are necessary to achieve this effect...
  2. ncbi Basal muscle amino acid kinetics and protein synthesis in healthy young and older men
    E Volpi
    Division of Endocrinology and Diabetes, University of Southern California, 1333 San Pablo St, BMT B11, Los Angeles, CA 90033, USA
    JAMA 286:1206-12. 2001
    ..Sarcopenia is associated with loss of strength and function, eventually leading to loss of independence. Some studies suggest that basal muscle protein turnover is reduced with aging, but other studies do not confirm this finding...
  3. ncbi Muscle tissue changes with aging
    Elena Volpi
    Division of Endocrinology and Diabetes, Department of Medicine, University of Southern California, Los Angeles, California, USA
    Curr Opin Clin Nutr Metab Care 7:405-10. 2004
    ..Particular emphasis is given to the metabolic alterations that characterize sarcopenia, and to the potentially treatable causes of this condition, including age-related endocrine and nutritional changes, and inactivity...
  4. ncbi Supraphysiological hyperinsulinaemia is necessary to stimulate skeletal muscle protein anabolism in older adults: evidence of a true age-related insulin resistance of muscle protein metabolism
    S Fujita
    Sealy Center on Aging, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555 0460, USA
    Diabetologia 52:1889-98. 2009
    ..We hypothesised that the age-related defect in muscle protein anabolism is a true insulin resistance state and can be overridden by supraphysiological hyperinsulinaemia...
  5. ncbi Resistance exercise increases leg muscle protein synthesis and mTOR signalling independent of sex
    H C Dreyer
    Division of Rehabilitation Sciences, Department of Physical Therapy, University of Texas Medical Branch, Galveston, TX 77555, USA
    Acta Physiol (Oxf) 199:71-81. 2010
    ..Therefore, the aim of this study was to determine if sex influences the muscle protein synthesis response during recovery from resistance exercise...
  6. ncbi Whole body and skeletal muscle glutamine metabolism in healthy subjects
    B Mittendorfer
    Department of Surgery, University of Texas Medical Branch at Galveston, Galveston, TX 77550, USA
    Am J Physiol Endocrinol Metab 280:E323-33. 2001
    ..Simultaneous ingestion of glucose diminishes the intramuscular glutamine concentration despite increased glutamine availability in the blood due to decreased glutamine production...
  7. ncbi Insulin resistance of muscle protein metabolism in aging
    Blake B Rasmussen
    Department of Kinesiology, University of Southern California, Los Angeles, California, USA
    FASEB J 20:768-9. 2006
    ..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...
  8. ncbi Measurement of skin protein breakdown in a rat model
    E Volpi
    Department of Internal Medicine, University of Texas Medical Branch, Galveston, 77555, USA
    Am J Physiol Endocrinol Metab 279:E900-6. 2000
    ..mixed protein FSR). The tracee release method is a sensitive method for measurement of skin protein breakdown; however, given the high intersubject variability of FSR, the calculation of skin net balance is not advisable...
  9. ncbi Oral and intravenously administered amino acids produce similar effects on muscle protein synthesis in the elderly
    B B Rasmussen
    University of Southern California, Department of Kinesiology, University Park Campus, 3560 Watt Way, PED 107, Los Angeles, CA 90089 0652, USA
    J Nutr Health Aging 6:358-62. 2002
    ..Muscle protein synthesis is stimulated in the elderly when amino acid availability is increased...
  10. ncbi Skeletal muscle protein anabolic response to resistance exercise and essential amino acids is delayed with aging
    Micah J Drummond
    Department of Physical Therapy, Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555 1144, USA
    J Appl Physiol 104:1452-61. 2008
    ..Notwithstanding, the combination of resistance exercise and EAA ingestion should be a useful strategy to combat sarcopenia...
  11. ncbi Short-term insulin and nutritional energy provision do not stimulate muscle protein synthesis if blood amino acid availability decreases
    Jill A Bell
    Sealy Center on Aging and Stark Diabetes Center, Department of Physical Therapy, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555-1144, USA
    Am J Physiol Endocrinol Metab 289:E999-1006. 2005
    ....
  12. ncbi Essential amino acids increase microRNA-499, -208b, and -23a and downregulate myostatin and myocyte enhancer factor 2C mRNA expression in human skeletal muscle
    Micah J Drummond
    Department of Physical Therapy, Division of Rehabilitation Science, University of Texas Medical Branch, Galveston, TX 77555, USA
    J Nutr 139:2279-84. 2009
    ..Further work is needed to determine whether these miRNA are post-transcriptional regulators of growth-related genes following an anabolic stimulus...
  13. ncbi Nutrient signalling in the regulation of human muscle protein synthesis
    Satoshi Fujita
    University of Texas Medical Branch, Department of Internal Medicine, Galveston, TX 77555 1144, USA
    J Physiol 582:813-23. 2007
    ....
  14. ncbi Effect of insulin on human skeletal muscle protein synthesis is modulated by insulin-induced changes in muscle blood flow and amino acid availability
    Satoshi Fujita
    Department of Medicine, University of Southern California, Los Angeles, California, USA
    Am J Physiol Endocrinol Metab 291:E745-54. 2006
    ..In conclusion, physiological hyperinsulinemia promotes muscle protein synthesis as long as it concomitantly increases muscle blood flow, amino acid delivery and availability...
  15. ncbi Leucine-enriched essential amino acid and carbohydrate ingestion following resistance exercise enhances mTOR signaling and protein synthesis in human muscle
    Hans C Dreyer
    Department of Physical Therapy, Division of Rehabilitation Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555 1144, USA
    Am J Physiol Endocrinol Metab 294:E392-400. 2008
    ..05). Our data suggest that enhanced activation of the mTOR signaling pathway is playing a role in the greater synthesis of muscle proteins when resistance exercise is followed by EAA+CHO ingestion...
  16. ncbi Amino acid metabolism and regulatory effects in aging
    Kyle L Timmerman
    Division of Geriatric Medicine, University of Texas Medical Branch, Galveston, Texas 77555 0460, USA
    Curr Opin Clin Nutr Metab Care 11:45-9. 2008
    ..To examine recent discoveries related to the amino acid metabolism and regulatory effects in aging, focusing on the development and treatment of age-related muscle loss (sarcopenia)...
  17. ncbi Malonyl coenzyme A and the regulation of functional carnitine palmitoyltransferase-1 activity and fat oxidation in human skeletal muscle
    Blake B Rasmussen
    Department of Surgery, University of Texas Medical Branch, Galveston, Texas, USA
    J Clin Invest 110:1687-93. 2002
    ..07 nmol/g during hyperglycemia with hyperinsulinemia. We conclude that hyperglycemia with hyperinsulinemia increases malonyl-CoA, inhibits functional CPT-1 activity, and shunts LCFA away from oxidation and toward storage in human muscle...
  18. ncbi Muscle protein breakdown has a minor role in the protein anabolic response to essential amino acid and carbohydrate intake following resistance exercise
    Erin L Glynn
    Univ of Texas Medical Branch, Dept of Physical Therapy, Galveston, TX 77555 1144, USA
    Am J Physiol Regul Integr Comp Physiol 299:R533-40. 2010
    ....
  19. ncbi Dysregulation of muscle fatty acid metabolism in type 2 diabetes is independent of malonyl-CoA
    J A Bell
    Department of Kinesiology, University of Southern California, Los Angeles, CA, USA
    Diabetologia 49:2144-52. 2006
    ..However, elevated fatty acid uptake in type 2 diabetes may be a key contributing factor to the increase in fatty acids being shunted towards storage within muscle...
  20. ncbi Essential amino acid and carbohydrate ingestion before resistance exercise does not enhance postexercise muscle protein synthesis
    Satoshi Fujita
    Univ of Texas Medical Branch, Dept of Physical Therapy, Div of Rehabilitation Sciences, Sealy Center on Aging, 301 Univ Blvd, Galveston, TX 77555 1144, USA
    J Appl Physiol 106:1730-9. 2009
    ..05). We conclude that EAA + CHO ingestion before resistance exercise does not enhance postexercise FSR compared with exercise without nutrients...
  21. ncbi Expression of growth-related genes in young and older human skeletal muscle following an acute stimulation of protein synthesis
    Micah J Drummond
    University of Texas Medical Branch, Department of Physical Therapy, Division of Rehabilitation Sciences, 301 Univ Blvd, Galveston, TX 77555 1144, USA
    J Appl Physiol 106:1403-11. 2009
    ..Our data provide new insights into the regulation of genes important for transcription and translation in young and old human skeletal muscle post RE+EAA...
  22. ncbi Amino acid ingestion improves muscle protein synthesis in the young and elderly
    Douglas Paddon-Jones
    Department of Surgery, The University of Texas Medical Branch, Galveston, Texas 77550, USA
    Am J Physiol Endocrinol Metab 286:E321-8. 2004
    ..Despite differences in the time course of plasma phenylalanine kinetics and a greater residual IC phenylalanine concentration, amino acid supplementation acutely stimulated muscle protein synthesis in both young and elderly individuals...
  23. ncbi Novel noninvasive breath test method for screening individuals at risk for diabetes
    E Lichar Dillon
    Department of Internal Medicine, The University of Texas Medical Branch, Galveston, Texas, USA
    Diabetes Care 32:430-5. 2009
    ....
  24. ncbi Pharmacological vasodilation improves insulin-stimulated muscle protein anabolism but not glucose utilization in older adults
    Kyle L Timmerman
    Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas, USA
    Diabetes 59:2764-71. 2010
    ..We hypothesized that, in older subjects, pharmacological restoration of insulin-induced capillary recruitment would improve the response of muscle protein synthesis and anabolism to insulin...
  25. ncbi Amino acids and muscle loss with aging
    Satoshi Fujita
    Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
    J Nutr 136:277S-80S. 2006
    ..For this reason, long-term essential amino acid supplementation may be a useful tool for the prevention and treatment of sarcopenia, particularly if excess leucine is provided in the supplement...
  26. ncbi Aerobic exercise overcomes the age-related insulin resistance of muscle protein metabolism by improving endothelial function and Akt/mammalian target of rapamycin signaling
    Satoshi Fujita
    Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas 77555 0460, USA
    Diabetes 56:1615-22. 2007
    ..05). In conclusion, a bout of aerobic exercise restores the anabolic response of muscle proteins to insulin by improving endothelial function and Akt/mTOR signaling in older subjects...
  27. ncbi Rapamycin administration in humans blocks the contraction-induced increase in skeletal muscle protein synthesis
    Micah J Drummond
    Departments of Physical Therapy, University of Texas Medical Branch, Galveston, 77555 1144, USA
    J Physiol 587:1535-46. 2009
    ....
  28. ncbi Insulin stimulates human skeletal muscle protein synthesis via an indirect mechanism involving endothelial-dependent vasodilation and mammalian target of rapamycin complex 1 signaling
    Kyle L Timmerman
    Sealy Center on Aging, Department of Internal Medicine, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555 0460, USA
    J Clin Endocrinol Metab 95:3848-57. 2010
    ..Our objective was to determine whether endothelial-dependent vasodilation is an essential mechanism by which insulin stimulates human skeletal muscle protein synthesis and anabolism...
  29. ncbi Resistance exercise increases human skeletal muscle AS160/TBC1D4 phosphorylation in association with enhanced leg glucose uptake during postexercise recovery
    Hans C Dreyer
    Univ of Texas Medical Branch, Dept of Physical Therapy, 301 Univ Blvd, Galveston, TX 77555 1144, USA
    J Appl Physiol 105:1967-74. 2008
    ..05). We conclude that resistance exercise increases AS160/TBC1D4 phosphorylation in association with an increase in leg glucose uptake during postexercise recovery...
  30. ncbi Excess leucine intake enhances muscle anabolic signaling but not net protein anabolism in young men and women
    Erin L Glynn
    Departments of Physical Therapy, University of Texas Medical Branch, Galveston, TX 77555, USA
    J Nutr 140:1970-6. 2010
    ..8 g) is sufficient to induce a maximal skeletal muscle protein anabolic response in young adults, but leucine may play a role in autophagy regulation...
  31. ncbi Sequential muscle biopsies during a 6-h tracer infusion do not affect human mixed muscle protein synthesis and muscle phenylalanine kinetics
    Elena Volpi
    Departments of Internal Medicine, University of Texas Medical Branch, Galveston, Texas 77555 0460, USA
    Am J Physiol Endocrinol Metab 295:E959-63. 2008
    ..Thus, when using a sequential study design over this period of time, it is unnecessary to include a saline only control group to account for these variables...
  32. ncbi Role of dietary protein in the sarcopenia of aging
    Douglas Paddon-Jones
    Department of Physical Therapy, The University of Texas Medical Branch, Galveston, TX 77555 1144, USA
    Am J Clin Nutr 87:1562S-1566S. 2008
    ..However, renal function decreases with age, and high protein intake is contraindicated in individuals with renal disease. Assessment of renal function is recommended for older individuals before they adopt a higher-protein diet...
  33. ncbi Role of protein and amino acids in the pathophysiology and treatment of sarcopenia
    Hans C Dreyer
    Department of Rehabilitative Sciences, University of Texas Medical Branch, Galveston, Texas 77555-0460, USA
    J Am Coll Nutr 24:140S-145S. 2005
    ..Thus, nutritional interventions may be useful for the prevention and treatment of sarcopenia...
  34. ncbi Skeletal muscle protein anabolic response to increased energy and insulin is preserved in poorly controlled type 2 diabetes
    Jill A Bell
    Department of Kinesiology, University of Southern California, Los Angeles, CA, USA
    J Nutr 136:1249-55. 2006
    ..Moreover, the anabolic response to increased insulin and energy availability is maintained in T2DM...
  35. ncbi Resistance exercise increases AMPK activity and reduces 4E-BP1 phosphorylation and protein synthesis in human skeletal muscle
    Hans C Dreyer
    University of Texas Medical Branch, Department of Physical Therapy, Division of Rehabilitation Sciences, 301 University Blvd, Galveston, TX 77555 1144, USA
    J Physiol 576:613-24. 2006
    ..However, by 1-2 h post-exercise, muscle protein synthesis increased in association with an activation of protein kinase B, mTOR, S6K1 and eEF2...
  36. ncbi Androgen therapy induces muscle protein anabolism in older women
    Melinda Sheffield-Moore
    University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0569, USA
    J Clin Endocrinol Metab 91:3844-9. 2006
    ..No change was noted in IGF-I expression in either group. We conclude that the skeletal muscle of older women and men responds to androgen administration, although the time course of anabolism appears to be gender specific...
  37. ncbi Amino acids are necessary for the insulin-induced activation of mTOR/S6K1 signaling and protein synthesis in healthy and insulin resistant human skeletal muscle
    Micah J Drummond
    Departments of Physical Therapy, University of Texas Medical Branch, Galveston, TX, USA
    Clin Nutr 27:447-56. 2008
    ..Amino acids (AA) activate the mammalian target of rapamycin (mTOR) signaling pathway but overactivation has a negative feedback effect on insulin signaling which may lead to insulin resistance and type 2 diabetes (T2DM)...
  38. ncbi Basal muscle intracellular amino acid kinetics in women and men
    Satoshi Fujita
    Univ of Texas Medical Branch, Sealy Center on Aging, Dept of Internal Medicine, 301 Univ Blvd, Galveston, TX 77555 0460, USA
    Am J Physiol Endocrinol Metab 292:E77-83. 2007
    ..It remains to be determined if there are sex differences in intracellular amino acid metabolism following anabolic or catabolic stimuli...
  39. ncbi Blood flow restriction during low-intensity resistance exercise increases S6K1 phosphorylation and muscle protein synthesis
    Satoshi Fujita
    Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
    J Appl Physiol 103:903-10. 2007
    ..We conclude that the activation of the mTOR signaling pathway appears to be an important cellular mechanism that may help explain the enhanced muscle protein synthesis during REFR...
  40. ncbi Amino acid metabolism and inflammatory burden in ovarian cancer patients undergoing intense oncological therapy
    E L Dillon
    Department of Internal Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555 1060, USA
    Clin Nutr 26:736-43. 2007
    ..Our considerable data showing the strong anabolic potential of amino acids (AA) led us to test whether AA can acutely stimulate muscle protein synthesis in cancer patients (CA) undergoing intense chemotherapy...
  41. ncbi Blood flow restriction exercise stimulates mTORC1 signaling and muscle protein synthesis in older men
    Christopher S Fry
    University of Texas Medical Branch, Sealy Center on Aging, Department of Physical Therapy, Division of Rehabilitation Sciences, 301 Univ Blvd, Galveston, TX 77555 1144, USA
    J Appl Physiol 108:1199-209. 2010
    ..05). We conclude that low-intensity RE in combination with BFR enhances mTORC1 signaling and MPS in older men. BFR exercise is a novel intervention that may enhance muscle rehabilitation to counteract sarcopenia...
  42. ncbi An increase in essential amino acid availability upregulates amino acid transporter expression in human skeletal muscle
    Micah J Drummond
    University of Texas Medical Branch, Department of Physical Therapy, Division of Rehabilitation Sciences, Sealy Center on Aging, 301 Univ Blvd, Galveston, TX 77555 1144, USA
    Am J Physiol Endocrinol Metab 298:E1011-8. 2010
    ..05). We conclude that an increase in EAA availability upregulates human skeletal muscle AA transporter expression, perhaps in an mTORC1-dependent manner, which may be an adaptive response necessary for improved AA intracellular delivery...
  43. ncbi Human muscle gene expression following resistance exercise and blood flow restriction
    Micah J Drummond
    Department of Physical Therapy, University of Texas Medical Branch, Galveston, TX, USA
    Med Sci Sports Exerc 40:691-8. 2008
    ..However, there are limited data describing the molecular adaptations that occur after REFR...
  44. ncbi The relationships between testosterone, body composition, and insulin resistance: a lesson from a case of extreme hyperandrogenism
    Elena Volpi
    Division of Geriatric Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555-0460, USA
    Diabetes Care 28:429-32. 2005