» Articles » PMID: 6661205

Bidirectional Transport of Glutamine Across the Cell Membrane in Rat Liver

Overview
Journal Biochem J
Specialty Biochemistry
Date 1983 Nov 15
PMID 6661205
Citations 10
Authors
Affiliations
Soon will be listed here.
Abstract

Hepatocytes isolated from fed rats were used to investigate glutamine transport. Glutamine transport appears as a composite process involving at least two saturable components. The Na+-dependent component probably represents the entry through the N system. The Na+-independent component was also inhibited by histidine and exhibited trans-stimulation, suggestive of a facilitated diffusion process. Kinetic parameters for both systems suggest that facilitated diffusion only plays a minor role in glutamine influx. In contrast, the Km for glutamine efflux was consistent with a physiological role of the facilitated-diffusion component in glutamine release. In Na+ medium, relatively constant distribution ratios (about 8) between intra- and extra-cellular concentrations were observed, with external glutamine ranging from 0.5 to 5 mM. The present observations suggest that glutamine influx might largely be mediated by the N system, whereas facilitated diffusion allows hepatocytes to release glutamine when intracellular concentrations are elevated. The physiological consequences of this bidirectional transfer of glutamine across the liver cell membrane is discussed.

Citing Articles

The Human SLC1A5 (ASCT2) Amino Acid Transporter: From Function to Structure and Role in Cell Biology.

Scalise M, Pochini L, Console L, Losso M, Indiveri C Front Cell Dev Biol. 2018; 6:96.

PMID: 30234109 PMC: 6131531. DOI: 10.3389/fcell.2018.00096.


Fluid and ion transfer across the blood-brain and blood-cerebrospinal fluid barriers; a comparative account of mechanisms and roles.

Hladky S, Barrand M Fluids Barriers CNS. 2016; 13(1):19.

PMID: 27799072 PMC: 5508927. DOI: 10.1186/s12987-016-0040-3.


Visualization of glutamine transporter activities in living cells using genetically encoded glutamine sensors.

Gruenwald K, Holland J, Stromberg V, Ahmad A, Watcharakichkorn D, Okumoto S PLoS One. 2012; 7(6):e38591.

PMID: 22723868 PMC: 3375291. DOI: 10.1371/journal.pone.0038591.


Bidirectional substrate fluxes through the system N (SNAT5) glutamine transporter may determine net glutamine flux in rat liver.

Baird F, Beattie K, Hyde A, Ganapathy V, Rennie M, Taylor P J Physiol. 2004; 559(Pt 2):367-81.

PMID: 15218073 PMC: 1665133. DOI: 10.1113/jphysiol.2003.060293.


Bench-to-bedside review: glucose production from the kidney.

Cano N Crit Care. 2002; 6(4):317-21.

PMID: 12225606 PMC: 137457. DOI: 10.1186/cc1517.


References
1.
Berry M, Friend D . High-yield preparation of isolated rat liver parenchymal cells: a biochemical and fine structural study. J Cell Biol. 1969; 43(3):506-20. PMC: 2107801. DOI: 10.1083/jcb.43.3.506. View

2.
WINDMUELLER H, Spaeth A . Identification of ketone bodies and glutamine as the major respiratory fuels in vivo for postabsorptive rat small intestine. J Biol Chem. 1978; 253(1):69-76. View

3.
Remesey C, Demigne C, Aufrere J . Inter-organ relationships between glucose, lactate and amino acids in rats fed on high-carbohydrate or high-protein diets. Biochem J. 1978; 170(2):321-9. PMC: 1183898. DOI: 10.1042/bj1700321. View

4.
Fehlmann M, Le Cam A, Kitabgi P, Rey J, Freychet P . Regulation of amino acid transport in the liver. Emergence of a high affinity transport system in isolated hepatocytes from fasting rats. J Biol Chem. 1979; 254(2):401-7. View

5.
Joseph S, BRADFORD N, McGivan J . Characteristics of the transport of alanine, serine and glutamine across the plasma membrane of isolated rat liver cells. Biochem J. 1978; 176(3):827-36. PMC: 1186306. DOI: 10.1042/bj1760827. View