| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph N1G 2W1; and 2 Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada L85 4L8
Monosodium
glutamate (MSG) ingestion is known to increase plasma glutamate
concentration, and MSG infusion stimulates insulin secretion. We
investigated the impact of MSG ingestion on both the plasma and
intramuscular amino acid pools. Nine postprandial adults ingested MSG
(150 mg/kg) and rested for 105 min. Venous blood was sampled
preingestion and then every 15 min; vastus lateralis muscle biopsies
were taken preingestion and at 45, 75, and 105 min postingestion.
Venous plasma glutamate and aspartate concentrations increased
(P 
0.05) ~700-800 and 300-400%, respectively,
after 30-45 min. Although several other plasma amino acids
increased modestly, the rise in glutamate accounted for ~80% of the
increase in total plasma amino acids. In addition, plasma insulin
increased threefold after 15 min; this occurred before a significant
increase in plasma glutamate, indicating a feed-forward stimulation
from the gastrointestinal tract. The intramuscular amino acid pool was
remarkably constant, with only glutamate increasing (P 0.05) by 3.56 mmol/kg dry wt. By 105 min, the plasma and muscle amino acids
had returned to resting concentrations. This increase in muscle
glutamate concentration could account for ~40% of the MSG ingested;
we propose that resting skeletal muscle is a major sink for the
glutamate and metabolizes it to aspartate.
insulin; aspartate; glutamine; transamination; gastrointestinal system; monosodium glutamate
This article has been cited by other articles:
|
|
 |
|
  M. Mourtzakis, T. E. Graham, J. Gonzalez-Alonso, and B. Saltin Glutamate availability is important in intramuscular amino acid metabolism and TCA cycle intermediates but does not affect peak oxidative metabolism J Appl Physiol, August 1, 2008; 105(2): 547 - 554. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Uneyama, A. Niijima, A. San Gabriel, and K. Torii Luminal amino acid sensing in the rat gastric mucosa Am J Physiol Gastrointest Liver Physiol, December 1, 2006; 291(6): G1163 - G1170. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Pacheco, H. Oliva, J. M. Martinez-Navio, N. Climent, F. Ciruela, J. M. Gatell, T. Gallart, J. Mallol, C. Lluis, and R. Franco Glutamate Released by Dendritic Cells as a Novel Modulator of T Cell Activation J. Immunol., November 15, 2006; 177(10): 6695 - 6704. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. A. Slattery, A. J. Page, C. L. Dorian, S. M. Brierley, and L. A. Blackshaw Potentiation of mouse vagal afferent mechanosensitivity by ionotropic and metabotropic glutamate receptors J. Physiol., November 15, 2006; 577(1): 295 - 306. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. P. Rutten, M. P. Engelen, E. F. Wouters, A. M. Schols, and N. E. Deutz Metabolic effects of glutamine and glutamate ingestion in healthy subjects and in persons with chronic obstructive pulmonary disease Am. J. Clinical Nutrition, January 1, 2006; 83(1): 115 - 123. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Mourtzakis and T. E. Graham Glutamate ingestion and its effects at rest and during exercise in humans J Appl Physiol, October 1, 2002; 93(4): 1251 - 1259. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Watford Net Interorgan Transport of L-Glutamate in Rats Occurs via the Plasma, Not via Erythrocytes J. Nutr., May 1, 2002; 132(5): 952 - 956. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Bruce, D. Constantin-Teodosiu, P. L. Greenhaff, L. H. Boobis, C. Williams, and J. L. Bowtell Glutamine supplementation promotes anaplerosis but not oxidative energy delivery in human skeletal muscle Am J Physiol Endocrinol Metab, April 1, 2001; 280(4): E669 - E675. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
