HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hundal, H S Articles by Watt, P W Search for Related Content PubMed PubMed Citation Articles by Hundal, H S Articles by Watt, P W

Department of Physiology, University of Dundee.

1. We have investigated glutamine transport in the perfused rat hindlimb using the paired-tracer isotope dilution technique. 2. Uptake of L-glutamine was stereospecific, saturable, sodium dependent, insulin sensitive and pH insensitive in the physiological range. The maximum capacity of transport (Vmax) under normal perfusate conditions at 37 degrees C, 145 mM-Na+ and in the absence of insulin was 1156 +/- 193 nmol min-1 g-1 with transport being half-maximal at a perfusate glutamine concentration of 9.25 +/- 1.15 mM. 3. The kinetics of Na+ dependence strongly suggested co-transport of Na+ and glutamine with a stoichiometry of 1:1; furthermore, Na+ activated the carrier without any change in the concentration of glutamine at which transport was half-maximal, i.e. a 'Vmax effect' rather than a 'Km effect'. 4. The characteristics of glutamine transport, especially its substrate specificity and the pattern of competitive and non-competitive inhibition of glutamine transport by other amino acids, suggest that it is mediated by a carrier or carriers for which asparagine and histidine are also suitable substrates. 5. The characteristics of muscle glutamine transport are related but distinct from those of system N identified in hepatocytes; we suggest that they are sufficiently distinct to justify the identification of a new variant of mammalian amino acid transport systems which may be identified by the symbol Nm. 6. The kinetic characteristics of system Nm are such that glutamine is likely to be the most rapidly exchanging amino acid across the muscle membrane at physiological intra- and extracellular glutamine concentrations. Its hormone and ion sensitivities are likely to be important in the physiological modulation of whole-body glutamine metabolism and also during derangements observed in disease and after injury.

This article has been cited by other articles:

				M. C. Onan, J. S. Fisher, J.-S. Ju, B. C. Fuchs, and B. P. Bode Type I Diabetes Affects Skeletal Muscle Glutamine Uptake in a Fiber-Specific Manner Experimental Biology and Medicine, October 1, 2005; 230(9): 606 - 611. [Abstract] [Full Text] [PDF]

				D. C. Gore, S. E. Wolf, A. P. Sanford, D. N. Herndon, and R. R. Wolfe Extremity hyperinsulinemia stimulates muscle protein synthesis in severely injured patients Am J Physiol Endocrinol Metab, April 1, 2004; 286(4): E529 - E534. [Abstract] [Full Text] [PDF]

				N. Hiscock, E. W. Petersen, K. Krzywkowski, J. Boza, J. Halkjaer-Kristensen, and B. K. Pedersen Glutamine supplementation further enhances exercise-induced plasma IL-6 J Appl Physiol, July 1, 2003; 95(1): 145 - 148. [Abstract] [Full Text] [PDF]

				G. E. Mann, D. L. Yudilevich, and L. Sobrevia Regulation of Amino Acid and Glucose Transporters in Endothelial and Smooth Muscle Cells Physiol Rev, January 1, 2003; 83(1): 183 - 252. [Abstract] [Full Text] [PDF]

				A. M. Karinch, C.-M. Lin, C. L. Wolfgang, M. Pan, and W. W. Souba Regulation of expression of the SN1 transporter during renal adaptation to chronic metabolic acidosis in rats Am J Physiol Renal Physiol, November 1, 2002; 283(5): F1011 - F1019. [Abstract] [Full Text] [PDF]

				E. Sakurai, T. Sakurada, Y. Ochiai, J. Yamakami, and Y. Tanaka Stereoselective transport of histidine in rat lung microvascular endothelial cells Am J Physiol Lung Cell Mol Physiol, June 1, 2002; 282(6): L1192 - L1197. [Abstract] [Full Text] [PDF]

				F. A. Chaudhry, R. J. Reimer, and R. H. Edwards The glutamine commute: take the N line and transfer to the A J. Cell Biol., April 29, 2002; 157(3): 349 - 355. [Abstract] [Full Text] [PDF]

				T. Nakanishi, R. Kekuda, Y.-J. Fei, T. Hatanaka, M. Sugawara, R. G. Martindale, F. H. Leibach, P. D. Prasad, and V. Ganapathy Cloning and functional characterization of a new subtype of the amino acid transport system N Am J Physiol Cell Physiol, December 1, 2001; 281(6): C1757 - C1768. [Abstract] [Full Text] [PDF]

				B. P. Bode Recent Molecular Advances in Mammalian Glutamine Transport J. Nutr., September 1, 2001; 131(9): 2475S - 2485. [Abstract] [Full Text] [PDF]

				B. Mittendorfer, E. Volpi, and R. R. Wolfe Whole body and skeletal muscle glutamine metabolism in healthy subjects Am J Physiol Endocrinol Metab, February 1, 2001; 280(2): E323 - E333. [Abstract] [Full Text] [PDF]

				B. A. C. van Acker, K. W. E. Hulsewé, A. J. M. Wagenmakers, P. B. Soeters, and M. F. von Meyenfeldt Glutamine Appearance Rate in Plasma Is Not Increased after Gastrointestinal Surgery in Humans J. Nutr., June 1, 2000; 130(6): 1566 - 1571. [Abstract] [Full Text]

				M. PALACIN, R. ESTEVEZ, J. BERTRAN, and A. ZORZANO Molecular Biology of Mammalian Plasma Membrane Amino Acid Transporters Physiol Rev, October 1, 1998; 78(4): 969 - 1054. [Abstract] [Full Text] [PDF]

				F. A. Chaudhry, R. J. Reimer, and R. H. Edwards The glutamine commute: take the N line and transfer to the A J. Cell Biol., April 29, 2002; 157(3): 349 - 355. [Abstract] [Full Text] [PDF]