Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Biophys J
2004 Jan 01;861 Pt 1:235-47. doi: 10.1016/S0006-3495(04)74099-0.
Show Gene links
Show Anatomy links
Facilitated lactate transport by MCT1 when coexpressed with the sodium bicarbonate cotransporter (NBC) in Xenopus oocytes.
Becker HM
,
Bröer S
,
Deitmer JW
.
???displayArticle.abstract???
Monocarboxylate transporters (MCT) and sodium-bicarbonate cotransporters (NBC) transport acid/base equivalents and coexist in many epithelial and glial cells. In nervous systems, the electroneutral MCT1 isoform cotransports lactate and other monocarboxylates with H+, and is believed to be involved in the shuttling of energy-rich substrates between astrocytes and neurons. The NBC cotransports bicarbonate with sodium and generates a membrane current. We have expressed these transporter proteins, cloned from rat brain (MCT1) and human kidney (NBC), alone and together, by injecting the cRNA into oocytes of the frog Xenopus laevis, and measured intracellular pH changes and membrane currents under voltage-clamp with intracellular microelectrodes, and radiolabeled lactate uptake into the oocytes. We determined the cytosolic buffer capacity, the H+ and lactate fluxes as induced by 3 and 10 mM lactate in oocytes expressing MCT1 and/or NBC, and in water-injected oocytes, in salines buffered with 5 mM HEPES alone or with 5% CO2/10 mM HCO3(-) (pH 7.0). In MCT1 + NBC- but not in MCT1- or NBC-expressing oocytes, lactate activated a Na+- and HCO3(-)-dependent membrane current, indicating that lactate/H+ cotransport via MCT1, due to the induced pH change, stimulates NBC activity. Lactate/H+ cotransport by MCT1 was increased about twofold when MCT1 was expressed together with NBC. Our results suggest that the facilitation of MCT1 transport activity is mainly due to the increase in apparent buffer capacity contributed by the NBC, and thereby suppresses the build-up of intracellular H+ during the influx of lactate/H+, which would reduce MCT1 activity. Hence these membrane transporters functionally cooperate and are able to increase ion/metabolite transport activity.
Abuladze,
Molecular cloning, chromosomal localization, tissue distribution, and functional expression of the human pancreatic sodium bicarbonate cotransporter.
1998, Pubmed,
Xenbase
Abuladze,
Molecular cloning, chromosomal localization, tissue distribution, and functional expression of the human pancreatic sodium bicarbonate cotransporter.
1998,
Pubmed
,
Xenbase
Bevensee,
An electrogenic Na(+)-HCO(-)(3) cotransporter (NBC) with a novel COOH-terminus, cloned from rat brain.
2000,
Pubmed
,
Xenbase
Bevensee,
Intracellular pH regulation in cultured astrocytes from rat hippocampus. I. Role Of HCO3-.
1997,
Pubmed
Boron,
Intracellular pH regulation in the renal proximal tubule of the salamander. Basolateral HCO3- transport.
1983,
Pubmed
Bröer,
Characterization of the monocarboxylate transporter 1 expressed in Xenopus laevis oocytes by changes in cytosolic pH.
1998,
Pubmed
,
Xenbase
Bröer,
Comparison of lactate transport in astroglial cells and monocarboxylate transporter 1 (MCT 1) expressing Xenopus laevis oocytes. Expression of two different monocarboxylate transporters in astroglial cells and neurons.
1997,
Pubmed
,
Xenbase
Brooks,
Lactate shuttles in nature.
2002,
Pubmed
Brune,
Evidence for electrogenic sodium-bicarbonate cotransport in cultured rat cerebellar astrocytes.
1994,
Pubmed
Burnham,
Cloning, renal distribution, and regulation of the rat Na+-HCO3- cotransporter.
1998,
Pubmed
Choi,
Cloning and characterization of a human electrogenic Na+-HCO-3 cotransporter isoform (hhNBC).
1999,
Pubmed
,
Xenbase
De Bruijne,
Kinetic analysis of L-lactate transport in human erythrocytes via the monocarboxylate-specific carrier system.
1983,
Pubmed
Deitmer,
Voltage-dependent clamp of intracellular pH of identified leech glial cells.
1995,
Pubmed
Deitmer,
A role for CO(2) and bicarbonate transporters in metabolic exchanges in the brain.
2002,
Pubmed
Deitmer,
The regulation of intracellular pH by identified glial cells and neurones in the central nervous system of the leech.
1987,
Pubmed
Deitmer,
Glial strategy for metabolic shuttling and neuronal function.
2000,
Pubmed
Deitmer,
An inwardly directed electrogenic sodium-bicarbonate co-transport in leech glial cells.
1989,
Pubmed
Deitmer,
Electrogenic sodium-dependent bicarbonate secretion by glial cells of the leech central nervous system.
1991,
Pubmed
Deitmer,
pH regulation and proton signalling by glial cells.
1996,
Pubmed
Deitmer,
Acid/base transport across the leech giant glial cell membrane at low external bicarbonate concentration.
1998,
Pubmed
Dringen,
Uptake of L-lactate by cultured rat brain neurons.
1993,
Pubmed
Eladari,
Polarized expression of different monocarboxylate transporters in rat medullary thick limbs of Henle.
1999,
Pubmed
Geers,
Carbon dioxide transport and carbonic anhydrase in blood and muscle.
2000,
Pubmed
Gerhart,
Expression of monocarboxylate transporter MCT1 by brain endothelium and glia in adult and suckling rats.
1997,
Pubmed
Giffard,
The electrogenic sodium bicarbonate cotransporter: developmental expression in rat brain and possible role in acid vulnerability.
2000,
Pubmed
,
Xenbase
Halestrap,
The proton-linked monocarboxylate transporter (MCT) family: structure, function and regulation.
1999,
Pubmed
,
Xenbase
Heyer,
Stoichiometry of the rat kidney Na+-HCO3- cotransporter expressed in Xenopus laevis oocytes.
1999,
Pubmed
,
Xenbase
Juel,
Current aspects of lactate exchange: lactate/H+ transport in human skeletal muscle.
2001,
Pubmed
Magistretti,
Energy on demand.
1999,
Pubmed
Munsch,
Sodium-bicarbonate cotransport current in identified leech glial cells.
1994,
Pubmed
Pellerin,
Expression of monocarboxylate transporter mRNAs in mouse brain: support for a distinct role of lactate as an energy substrate for the neonatal vs. adult brain.
1998,
Pubmed
Poitry-Yamate,
Lactate released by Müller glial cells is metabolized by photoreceptors from mammalian retina.
1995,
Pubmed
Romero,
Electrogenic Na+/HCO3- cotransporters: cloning and physiology.
1999,
Pubmed
Romero,
Expression cloning and characterization of a renal electrogenic Na+/HCO3- cotransporter.
1997,
Pubmed
,
Xenbase
Schmitt,
Na/HCO3 cotransporters in rat brain: expression in glia, neurons, and choroid plexus.
2000,
Pubmed
Schurr,
Lactic acidosis and recovery of neuronal function following cerebral hypoxia in vitro.
1988,
Pubmed
Schurr,
Brain lactate is an obligatory aerobic energy substrate for functional recovery after hypoxia: further in vitro validation.
1997,
Pubmed
Schurr,
Blockade of lactate transport exacerbates delayed neuronal damage in a rat model of cerebral ischemia.
2001,
Pubmed
Sciortino,
Cation and voltage dependence of rat kidney electrogenic Na(+)-HCO(-)(3) cotransporter, rkNBC, expressed in oocytes.
1999,
Pubmed
,
Xenbase
Svichar,
Surface carbonic anhydrase activity on astrocytes and neurons facilitates lactate transport.
2003,
Pubmed
Thomas,
Homeostatic muffling.
1991,
Pubmed
Tong,
Interstitial carbonic anhydrase (CA) activity in brain is attributable to membrane-bound CA type IV.
2000,
Pubmed
Tsacopoulos,
Metabolic coupling between glia and neurons.
1996,
Pubmed
Voutsinos-Porche,
Glial glutamate transporters mediate a functional metabolic crosstalk between neurons and astrocytes in the mouse developing cortex.
2003,
Pubmed
Wetzel,
Extracellular carbonic anhydrase activity facilitates lactic acid transport in rat skeletal muscle fibres.
2001,
Pubmed
