Linked Life Data

11805232

Source:http://linkedlifedata.com/resource/pubmed/id/11805232

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-1-25
pubmed:abstractText
Rat P2X(1) and P2X(2) subunits were coexpressed in defolliculated Xenopus oocytes and the resultant P2X receptors studied under voltage-clamp conditions. Extracellular ATP elicited biphasic inward currents, involving an initial rapidly inactivating (P2X(1)-like) component and a later slowly inactivating (P2X(2)-like) component. The maximum amplitude of P2X(1)-like ATP responses was increased in some cells by lowering extracellular pH (from 7.5 to 6.5), whereas P2X(2)-like responses and those of homomeric rP2X(1) and rP2X(2) receptors were not changed by this treatment. Concentration-response (C/R) curves for ATP for pH-enhanced P2X(1)-like responses were biphasic, and clearly distinct from monophasic ATP C/R curves for homomeric rP2X(1) and rP2X(2) receptors. Under acidic (pH 5.5 and 6.5) and alkaline (pH 8.5) conditions, ATP C/R curves for P2X(1)-like responses showed increases in agonist potency and efficacy, compared with data at pH 7.5, but the same was not true of homomeric rP2X(1) and rP2X(2) receptors. ATP C/R curves for P2X(2)-like responses overlay C/R curves for homomeric rP2X(2) receptors, and determinations of agonist potency and efficacy were identical for P2X(2)-like and P2X(2) responses at all pH levels tested. Our results show that P2X(1)-like responses possessed the kinetics of homomeric P2X(1) receptors but an acid sensitivity different from homomeric P2X(1) and P2X(2) receptors. In contrast, the P2X(2)-like responses exactly matched the profile expected of homomeric P2X(2) receptors. Thus, coexpression of P2X(1) and P2X(2) subunits yielded a mixed population of homomeric and heteromeric P2X receptors, with a subpopulation of novel pH-sensitive P2X receptors showing identifiably unique properties that indicated the formation of heteromeric P2X(1/2) ion channels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
300
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
673-80
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:11805232-Adenosine Triphosphate, pubmed-meshheading:11805232-Animals, pubmed-meshheading:11805232-Electrophysiology, pubmed-meshheading:11805232-Extracellular Space, pubmed-meshheading:11805232-Humans, pubmed-meshheading:11805232-Hydrogen-Ion Concentration, pubmed-meshheading:11805232-Membrane Potentials, pubmed-meshheading:11805232-Oocytes, pubmed-meshheading:11805232-Patch-Clamp Techniques, pubmed-meshheading:11805232-Phenotype, pubmed-meshheading:11805232-Purinergic P2 Receptor Agonists, pubmed-meshheading:11805232-Receptors, Purinergic P2, pubmed-meshheading:11805232-Receptors, Purinergic P2X, pubmed-meshheading:11805232-Receptors, Purinergic P2X2, pubmed-meshheading:11805232-Recombinant Proteins, pubmed-meshheading:11805232-Synaptic Transmission, pubmed-meshheading:11805232-Xenopus
pubmed:year
2002
pubmed:articleTitle
Heteromultimeric P2X(1/2) receptors show a novel sensitivity to extracellular pH.
pubmed:affiliation
Autonomic Neuroscience Institute, Royal Free and University College Medical School, Royal Free Campus, Hampstead, United Kingdom.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't