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.
Pflugers Arch
2003 Mar 01;4456:716-20. doi: 10.1007/s00424-002-1002-y.
Show Gene links
Show Anatomy links
Effects of extracellular sodium on mu-opioid receptors coupled to potassium channels coexpressed in Xenopus oocytes.
Oz M
,
Spivak CE
.
???displayArticle.abstract???
Wild-type or mutant H297N or H297Q of the mu-opioid receptor were co-expressed with the inwardly rectifying potassium channel GIRK1 in oocytes from Xenopus laevis. Under voltage clamp, pairs of concentration response curves were generated using the agonist normorphine in a bathing medium containing 38.5 mM sodium or an identical medium in which the sodium was replaced by an equimolar concentration of choline. The maximum currents were greater in the presence of sodium by about 30% at wild-type receptors and by about 100% at the mutant receptors. The EC(50) values tended to increase somewhat as well, though these differences reached statistical significance only for the mutant H297Q. Flame photometry detected no change in the intracellular sodium or potassium concentrations of oocytes, suggesting that the effect of sodium was solely extracellular. Thus sodium, long known for its effects on in vitro ligand binding at mu-opioid receptors, also affects overall transduction as revealed in the Xenopus oocyte model of a complete, living cell system.
Blume,
Interaction of ligands with the opiate receptors of brain membranes: regulation by ions and nucleotides.
1978, Pubmed
Blume,
Interaction of ligands with the opiate receptors of brain membranes: regulation by ions and nucleotides.
1978,
Pubmed
Connolly,
The influence of Na+ on the alpha 2-adrenergic receptor system of human platelets. A method for removal of extraplatelet Na+. Effect of Na+ removal on aggregation, secretion, and cAMP accumulation.
1983,
Pubmed
Costa,
Spontaneous association between opioid receptors and GTP-binding regulatory proteins in native membranes: specific regulation by antagonists and sodium ions.
1990,
Pubmed
Costa,
Drug efficacy at guanine nucleotide-binding regulatory protein-linked receptors: thermodynamic interpretation of negative antagonism and of receptor activity in the absence of ligand.
1992,
Pubmed
Dascal,
Atrial G protein-activated K+ channel: expression cloning and molecular properties.
1993,
Pubmed
,
Xenbase
Dascal,
Signalling via the G protein-activated K+ channels.
1997,
Pubmed
Fischel,
Assessment of membrane permeability in primary cultures of neurons and glia in response to osmotic perturbation.
1985,
Pubmed
Gray,
Sodium dependency of constitutive activity at 5-HT1D alpha/1D beta receptors.
1997,
Pubmed
Hamblin,
3H-dopamine binding to rat striatal D-2 and D-3 sites: enhancement by magnesium and inhibition by guanine nucleotides and sodium.
1982,
Pubmed
Harikumar,
Modulation of antagonist binding to serotonin1A receptors from bovine hippocampus by metal ions.
2001,
Pubmed
Johansson,
Effects of mono- and divalent ions on the binding of the adenosine analogue CGS 21680 to adenosine A2 receptors in rat striatum.
1992,
Pubmed
Kenakin,
Drug efficacy at G protein-coupled receptors.
2002,
Pubmed
Lesage,
Molecular properties of neuronal G-protein-activated inwardly rectifying K+ channels.
1995,
Pubmed
,
Xenbase
Limbird,
Sodium ion modulates agonist and antagonist interactions with the human platelet alpha 2-adrenergic receptor in membrane and solubilized preparations.
1982,
Pubmed
Neve,
Regulation of dopamine D2 receptors by sodium and pH.
1991,
Pubmed
Pacheco,
Differential requirements of sodium for coupling of cannabinoid receptors to adenylyl cyclase in rat brain membranes.
1994,
Pubmed
Pert,
Opiate agonists and antagonists discriminated by receptor binding in brain.
1973,
Pubmed
Puttfarcken,
Sodium regulation of agonist binding at opioid receptors. I. Effects of sodium replacement on binding at mu- and delta-type receptors in 7315c and NG108-15 cells and cell membranes.
1986,
Pubmed
Selley,
Effects of sodium on agonist efficacy for G-protein activation in mu-opioid receptor-transfected CHO cells and rat thalamus.
2000,
Pubmed
Shea,
Timing is everything the role of kinetics in G protein activation.
2000,
Pubmed
Simon,
Further properties of stereospecific opiate binding sites in rat brain: on the nature of the sodium effect.
1975,
Pubmed
Snutch,
The use of Xenopus oocytes to probe synaptic communication.
1988,
Pubmed
,
Xenbase
Spivak,
Naloxone activation of mu-opioid receptors mutated at a histidine residue lining the opioid binding cavity.
1997,
Pubmed
,
Xenbase
Sui,
Na+ activation of the muscarinic K+ channel by a G-protein-independent mechanism.
1996,
Pubmed
,
Xenbase
Theodoulou,
Xenopus oocytes as a heterologous expression system.
1995,
Pubmed
,
Xenbase
Thomsen,
Rapid kinetics of alpha 2-adrenergic inhibition of adenylate cyclase. Evidence for a distal rate-limiting step.
1989,
Pubmed
Tian,
Precoupling of Gi/G(o)-linked receptors and its allosteric regulation by monovalent cations.
1993,
Pubmed
Toll,
Mu-opioid receptor binding in intact SH-SY5Y neuroblastoma cells.
1990,
Pubmed
Tsai,
Agonist-specific effects of monovalent and divalent cations on adenylate cyclase-coupled alpha adrenergic receptors in rabbit platelets.
1978,
Pubmed
Underwood,
Getting it together: signal transduction in G-protein coupled receptors by association of receptor domains.
1997,
Pubmed
Waelbroeck,
Kinetics versus equilibrium: the importance of GTP in GPCR activation.
1999,
Pubmed
Wagner,
The use of Xenopus laevis oocytes for the functional characterization of heterologously expressed membrane proteins.
2000,
Pubmed
,
Xenbase
Yabaluri,
Regulation of mu-opioid receptor in neural cells by extracellular sodium.
1997,
Pubmed