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. 1986 Jan 15;233(2):499–506. doi: 10.1042/bj2330499

Transport of the aromatic amino acids into isolated rat liver cells. Properties of uptake by two distinct systems.

M Salter, R G Knowles, C I Pogson
PMCID: PMC1153053  PMID: 3954748

Abstract

The transport of the aromatic amino acids into isolated rat liver cells was studied. There was a rapid and substantial binding of the aromatic amino acids, L-alanine and L-leucine to the plasma membrane. This has important consequences for the determination of rates of transport and intracellular concentrations of the amino acids. Inhibition studies with a variety of substrates of various transport systems gave results consistent with aromatic amino acid transport being catalysed by two systems: a 2-aminobicyclo(2,2,1)heptane-2-carboxylic acid (BCH)-insensitive aromatic D- and L-amino acid-specific system, and the L-type system (BCH-sensitive). The BCH-insensitive component of transport was Na+-independent and facilitated non-concentrative transport of the aromatic amino acids; it was unaffected by culture of liver cells for 24 h, by 48 h starvation, dexamethasone phosphate or glucagon. Kinetic properties of the BCH-inhibitable component were similar to those previously reported for the L2-system in liver cells. The BCH-insensitive component was a comparatively low-Km low-Vmax. transport system that we suggest is similar to the T-transport system previously seen only in human red blood cells. The results are discussed with reference to the importance of the T- and L-systems in the control of aromatic L-amino acid degradation in the liver.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Aragón M. C., Giménez C., Mayor F., Jr, Marvizón J. G., Valdivieso F. Tyrosine transport by membrane vesicles isolated from rat brain. Biochim Biophys Acta. 1981 Sep 7;646(3):465–470. doi: 10.1016/0005-2736(81)90316-3. [DOI] [PubMed] [Google Scholar]
  2. Badawy A. A., Evans M. The effects of acute and chronic nicotine hydrogen (+)-tartrate administration and subsequent withdrawal on rat liver tryptophan pyrrolase activity and their comparison with those of morphine, phenobarbitone and ethanol. Biochem J. 1975 Jun;148(3):425–432. doi: 10.1042/bj1480425. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bloxam D. L., Tricklebank M. D., Patel A. J., Curzon G. Effects of albumin, amino acids, and clofibrate on the uptake of tryptophan by the rat brain. J Neurochem. 1980 Jan;34(1):43–49. doi: 10.1111/j.1471-4159.1980.tb04619.x. [DOI] [PubMed] [Google Scholar]
  4. Carr F. P., Pogson C. I. Phenylalanine metabolism in isolated rat liver cells. Effects of glucagon and diabetes. Biochem J. 1981 Sep 15;198(3):655–660. doi: 10.1042/bj1980655. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Christensen H. N. Exploiting amino acid structure to learn about membrane transport. Adv Enzymol Relat Areas Mol Biol. 1979;49:41–101. doi: 10.1002/9780470122945.ch2. [DOI] [PubMed] [Google Scholar]
  6. Coufalik A. H., Monder C. Regulation of the tyrosine oxidizing system in fetal rat liver. Arch Biochem Biophys. 1980 Jan;199(1):67–75. doi: 10.1016/0003-9861(80)90257-x. [DOI] [PubMed] [Google Scholar]
  7. Dickson A. J., Marston F. A., Pogson C. I. Tyrosine aminotransferase as the rate-limiting step for tyrosine catabolism in isolated rat liver cells. FEBS Lett. 1981 May 5;127(1):28–32. doi: 10.1016/0014-5793(81)80333-x. [DOI] [PubMed] [Google Scholar]
  8. Fernstrom J. D., Wurtmen R. J. Elevation of plasma tryptophan by insulin in rat. Metabolism. 1972 Apr;21(4):337–342. doi: 10.1016/0026-0495(72)90078-9. [DOI] [PubMed] [Google Scholar]
  9. Fisher M. J., Pogson C. I. Phenylalanine hydroxylase in liver cells. Correlation of glucagon-stimulated enzyme phosphorylation with expressed activity. Biochem J. 1984 Apr 1;219(1):79–85. doi: 10.1042/bj2190079. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Guidotti G. G., Borghetti A. F., Gazzola G. C. The regulation of amino acid transport in animal cells. Biochim Biophys Acta. 1978 Dec 15;515(4):329–366. doi: 10.1016/0304-4157(78)90009-6. [DOI] [PubMed] [Google Scholar]
  11. Handlogten M. E., Weissbach L., Kilberg M. S. Heterogeneity of Na+-independent 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid and L-leucine transport in isolated rat hepatocytes in primary culture. Biochem Biophys Res Commun. 1982 Jan 15;104(1):307–313. doi: 10.1016/0006-291x(82)91975-1. [DOI] [PubMed] [Google Scholar]
  12. Inui Y., Christensen H. N. Discrimination of single transport systems. The Na plus-sensitive transport of neutral amino acids in the Ehrlich cell. J Gen Physiol. 1966 Sep;50(1):203–224. doi: 10.1085/jgp.50.1.203. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kilberg M. S. Amino acid transport in isolated rat hepatocytes. J Membr Biol. 1982;69(1):1–12. doi: 10.1007/BF01871236. [DOI] [PubMed] [Google Scholar]
  14. Kilberg M. S., Handlogten M. E., Christensen H. N. Characteristics of system ASC for transport of neutral amino acids in the isolated rat hepatocyte. J Biol Chem. 1981 Apr 10;256(7):3304–3312. [PubMed] [Google Scholar]
  15. Knowles R. G., Pogson C. I. Characteristics of tryptophan accumulation by isolated rat forebrain synaptosomes. J Neurochem. 1984 Mar;42(3):663–669. doi: 10.1111/j.1471-4159.1984.tb02734.x. [DOI] [PubMed] [Google Scholar]
  16. Knowles R. G., Pogson C. I. Tryptophan uptake and hydroxylation in rat forebrain synaptosomes. J Neurochem. 1984 Mar;42(3):677–684. doi: 10.1111/j.1471-4159.1984.tb02736.x. [DOI] [PubMed] [Google Scholar]
  17. Le Cam A., Freychet P. Neutral amino acid transport. Characterization of the A and L systems in isolated rat hepatocytes. J Biol Chem. 1977 Jan 10;252(1):148–156. [PubMed] [Google Scholar]
  18. McGivan J. D., Bradford N. M., Mendes-Mourão J. The transport of branched-chain amino acids into isolated rat liver cells. FEBS Lett. 1977 Aug 15;80(2):380–384. doi: 10.1016/0014-5793(77)80481-x. [DOI] [PubMed] [Google Scholar]
  19. Milstien S., Kaufman S. Studies on the phenylalanine hydroxylase system in vivo. An in vivo assay based on the liberation of deuterium or tritium into the body water from ring-labeled L-phenylalanine. J Biol Chem. 1975 Jun 25;250(12):4782–4785. [PubMed] [Google Scholar]
  20. OXENDER D. L., CHRISTENSEN H. N. DISTINCT MEDIATING SYSTEMS FOR THE TRANSPORT OF NEUTRAL AMINO ACIDS BY THE EHRLICH CELL. J Biol Chem. 1963 Nov;238:3686–3699. [PubMed] [Google Scholar]
  21. Pardridge W. M. Kinetics of competitive inhibition of neutral amino acid transport across the blood-brain barrier. J Neurochem. 1977 Jan;28(1):103–108. doi: 10.1111/j.1471-4159.1977.tb07714.x. [DOI] [PubMed] [Google Scholar]
  22. Rosenberg R., Young J. D., Ellory J. C. L-Tryptophan transport in human red blood cells. Biochim Biophys Acta. 1980 May 23;598(2):375–384. doi: 10.1016/0005-2736(80)90015-2. [DOI] [PubMed] [Google Scholar]
  23. Salter M., Bender D. A., Pogson C. I. Leucine and tryptophan metabolism in rats. Biochem J. 1985 Jan 15;225(2):277–281. doi: 10.1042/bj2250277. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Salter M., Stanley J. C., Fisher M. J., Pogson C. I. The influence of starvation and tryptophan administration on the metabolism of phenylalanine, tyrosine and tryptophan in isolated rat liver cells. Biochem J. 1984 Jul 15;221(2):431–438. doi: 10.1042/bj2210431. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Shotwell M. A., Kilberg M. S., Oxender D. L. The regulation of neutral amino acid transport in mammalian cells. Biochim Biophys Acta. 1983 May 24;737(2):267–284. doi: 10.1016/0304-4157(83)90003-5. [DOI] [PubMed] [Google Scholar]
  26. Smith S. A., Carr F. P., Pogson C. I. The metabolism of L-tryptophan by isolated rat liver cells. Quantification of the relative importance of, and the effect of nutritional status on, the individual pathways of tryptophan metabolism. Biochem J. 1980 Nov 15;192(2):673–686. doi: 10.1042/bj1920673. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Smith S. A., Pogson C. I. The metabolism of L-tryptophan by isolated rat liver cells. Effect of albumin binding and amino acid competition on oxidatin of tryptophan by tryptophan 2,3-dioxygenase. Biochem J. 1980 Mar 15;186(3):977–986. doi: 10.1042/bj1860977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Stanley P. E., Williams S. G. Use of the liquid scintillation spectrometer for determining adenosine triphosphate by the luciferase enzyme. Anal Biochem. 1969 Jun;29(3):381–392. doi: 10.1016/0003-2697(69)90323-6. [DOI] [PubMed] [Google Scholar]
  29. Stewart K. K., Doherty R. F. Resolution of DL-tryptophan by affinity chromatography on bovine-serum albumin-agarose columns. Proc Natl Acad Sci U S A. 1973 Oct;70(10):2850–2852. doi: 10.1073/pnas.70.10.2850. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Tanaka K., Ichihara A. Control of ketogenesis from amino acids. III. In vitro and in vivo studies on ketone body formation lipogenesis and oxidation of tyrosine by rats. Biochim Biophys Acta. 1975 Aug 13;399(2):302–312. [PubMed] [Google Scholar]
  31. Weissbach L., Handlogten M. E., Christensen H. N., Kilberg M. S. Evidence for two Na+-independent neutral amino acid transport systems in primary cultures of rat hepatocytes. Time-dependent changes in activity. J Biol Chem. 1982 Oct 25;257(20):12006–12011. [PubMed] [Google Scholar]

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