Skip to main content
Biochemical Journal logoLink to Biochemical Journal
. 1978 Dec 15;176(3):827–836. doi: 10.1042/bj1760827

Characteristics of the transport of alanine, serine and glutamine across the plasma membrane of isolated rat liver cells.

S K Joseph, N M Bradford, J D McGivan
PMCID: PMC1186306  PMID: 747655

Abstract

1. Alanine, glutamine and serine were actively accumulated in liver cells isolated from starved rats. 2. This accumulation was inhibited when either Na+ or HCO3- ions were omitted from the incubation medium. In general the degree of dependence on Na+ was quantitatively similar to that on HCO3-. 3. The apparent Km values for the transport of all three amino acids were in the range 3--5mM with Vmax. values in the range 15--25nmol/min per mg of cell protein at 37 degrees C. 4. Alanine and serine transport were mutually competitive; glutamine inhibited the transport of alanine and serine non-competitively. 5. The initial rate of transport of these amino acids was inhibited when the intracellular content of ATP was decreased. 6. Ouabain inhibited the rate of alanine transport without inhibiting the rate of alanine metabolism. 7. It is concluded that a minimum of three transport systems must be postulated to exist in the liver cell plasma membrane to account for the transport of alanine, serine and glutamine. The rate of transport of these amino acids in isolated hepatocytes is unlikely to limit the rate at which they are metabolized.

Full text

PDF
827

Selected References

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

  1. Berry M. N., Friend D. S. High-yield preparation of isolated rat liver parenchymal cells: a biochemical and fine structural study. J Cell Biol. 1969 Dec;43(3):506–520. doi: 10.1083/jcb.43.3.506. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bloxam D. L. Nutritional aspects of amino acid metabolism. 2. The effects of starvation on hepatic portal-venous differences in plasma amino acid concentration and on liver amino acid concentrations in the rat. Br J Nutr. 1972 Mar;27(2):233–247. doi: 10.1079/bjn19720090. [DOI] [PubMed] [Google Scholar]
  3. Chamalaun R. A., Tager J. M. Nitrogen metabolism in the perfused rat liver. Biochim Biophys Acta. 1970 Oct 27;222(1):119–134. doi: 10.1016/0304-4165(70)90357-0. [DOI] [PubMed] [Google Scholar]
  4. Christensen H. N. Some special kinetic problems of transport. Adv Enzymol Relat Areas Mol Biol. 1969;32:1–20. doi: 10.1002/9780470122778.ch1. [DOI] [PubMed] [Google Scholar]
  5. Crawhall J. C., Segal S. Transport of some amino acids and sugars in rat-liver slices. Biochim Biophys Acta. 1968 Sep 17;163(2):163–170. doi: 10.1016/0005-2736(68)90094-1. [DOI] [PubMed] [Google Scholar]
  6. Edmondson J. W., Lumeng L., Li T. K. Direct measurement of active transport systems for alanine in freshly isolated rat liver cells. Biochem Biophys Res Commun. 1977 Jun 6;76(3):751–757. doi: 10.1016/0006-291x(77)91564-9. [DOI] [PubMed] [Google Scholar]
  7. Fernstrom J. D., Larin F., Wurtman R. J. Daily variations in the concentrations of individual amino acids in rat plasma. Life Sci I. 1971 Jul 15;10(14):813–819. doi: 10.1016/0024-3205(71)90036-1. [DOI] [PubMed] [Google Scholar]
  8. Jefferson L. S., Schworer C. M., Tolman E. L. Growth hormone stimulation of amino acid transport and utilization by the perfused rat liver. J Biol Chem. 1975 Jan 10;250(1):197–204. [PubMed] [Google Scholar]
  9. Joseph S. K., McGivan J. D. The effect of ammonium chloride and glucagon on the metabolism of glutamine in isolated liver cells from starved rats. Biochim Biophys Acta. 1978 Sep 21;543(1):16–28. doi: 10.1016/0304-4165(78)90450-6. [DOI] [PubMed] [Google Scholar]
  10. Krebs H. A., Hems R., Lund P. Some regulatory mechanisms in the synthesis of urea in the mammalian liver. Adv Enzyme Regul. 1973;11:361–377. doi: 10.1016/0065-2571(73)90024-1. [DOI] [PubMed] [Google Scholar]
  11. 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]
  12. Mallette L. E., Exton J. H., Park Effects of glucagon on amino acid transport and utilization in the perfused rat liver. J Biol Chem. 1969 Oct 25;244(20):5724–5728. [PubMed] [Google Scholar]
  13. McGivan J. D., Bradford N. M., Beavis A. D. Factors influencing the activity of ornithine aminotransferase in isolated rat liver mitochondria. Biochem J. 1977 Jan 15;162(1):147–156. doi: 10.1042/bj1620147. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. 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]
  15. 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]
  16. Ross B. D., Hems R., Krebs H. A. The rate of gluconeogenesis from various precursors in the perfused rat liver. Biochem J. 1967 Mar;102(3):942–951. doi: 10.1042/bj1020942. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Tews J. K., Harper A. E. Transport of nonmetabolizable amino acids in rat liver slices. Biochim Biophys Acta. 1969;183(3):601–610. doi: 10.1016/0005-2736(69)90173-4. [DOI] [PubMed] [Google Scholar]
  18. Tews J. K., Woodcock N. A., Harper A. E. Stimulation of amino acid transport in rat liver slices by epinephrine, glucagon, and adenosine 3',5'-monophosphate. J Biol Chem. 1970 Jun 10;245(11):3026–3032. [PubMed] [Google Scholar]
  19. Williamson D. H., Lopes-Vieira O., Walker B. Concentrations of free glucogenic amino acids in livers of rats subjected to various metabolic stresses. Biochem J. 1967 Aug;104(2):497–502. doi: 10.1042/bj1040497. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES