Linked Life Data

7565627

Source:http://linkedlifedata.com/resource/pubmed/id/7565627

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-10-30
pubmed:abstractText
Cell volume regulation in different cell types is mediated in part by plasma membrane channel(s) that allow taurine and other important intracellular organic osmolytes to efflux from the cell. Previous studies have demonstrated that intracellular ATP is required for activation of a volume-sensitive taurine-permeable channel. The present study examined the relation between cellular ATP and ADP concentrations and swelling-induced [14C]taurine efflux and anion current (whole-cell patch-clamp) after exposure of isolated skate (Raja erinacea) hepatocytes to metabolic poisons and a series of ion channel blockers. When intracellular ATP content was lowered with gradually increasing concentrations of 2,4-dinitrophenol, a sigmoidal relation between ATP content and volume-activated [14C]taurine efflux was observed. Taurine efflux was progressively inhibited over a relatively narrow range of intracellular ATP levels, indicating that physiologic alterations in cellular nucleotides may modulate the opening of the channel. Surprisingly, the inhibition of [14C]taurine efflux by a number of ion channel blockers [glibenclamide, 5-nitro-2-(3-phenylpropylamino)benzoate, diphenylamine-2-carboxylate, ketoconazole, gossypol, niflumic acid, and quinine] was related to a decrease in cellular ATP concentrations and ATP/ADP ratios, rather than to a direct interaction with the channel. In contrast, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid and pyridoxal-5-phosphate inhibited volume-activated anion channels but had no effect on cellular ATP levels. These findings suggest multiple sites for regulation of volume-sensitive osmolyte channels and indicate that some putative ion channel blockers may actually alter the activity of ATP-regulated transporters by depleting cellular ATP.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
472-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
ATP depletion and inactivation of an ATP-sensitive taurine channel by classic ion channel blockers.
pubmed:affiliation
Department of Environmental Medicine, University of Rochester School of Medicine, New York 14642, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't