Linked Life Data

8717166

Source:http://linkedlifedata.com/resource/pubmed/id/8717166

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-10-22
pubmed:abstractText
In numerous studies the intracellular mononucleotide-dependent gating of ATP-sensitive K+ (KATP) channels has been demonstrated. However, it is not known whether dinucleotide polyphosphates, a family of endogenous compounds structurally-related to ATP, could also modulate this ion conductance. Therefore, in the present study we assessed the direct effect of diadenosine 5',5''-P1,P5-pentaphosphate (Ap5A) on cardiac KATP channel activity using the inside-out configuration of the patch-clamp technique. Addition of Ap5A (50 microM) to the internal side of membrane patches, excised from guinea-pig ventricular cells, strongly inhibited KATP channel activity. The estimated NPO (where N is the number of channels in the patch and PO the open probability of each channel) was 4.16 +/- 0.50 in the absence and 0.85 +/- 0.30 in the presence of Ap5A (50 microM). This effect of Ap5A was partially reversible, and the NP0 was 2.26 +/- 0.60 after washout of Ap5A. Exposure of KATP channels to increasing concentrations of Ap5A revealed that the Ap5A-induced inhibition is concentration-dependent with the half-maximal effective concentration of 16 microM (Hill coefficient: 1.6). On the basis of these results, we conclude that Ap5A is a potent antagonist of the KATP channel activity. This represents a previously unrecognized property of Ap5A, as well as the discovery of a potentially novel endogenous ligand of myocardial KATP channels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0028-1298
pubmed:author
pubmed:issnType
Print
pubmed:volume
353
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
241-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Cardiac ATP-sensitive K+ channel: a target for diadenosine 5',5''-P1,P5-pentaphosphate.
pubmed:affiliation
Division of Cardiovascular Diseases, Mayo Clinic, Mayo Foundation, Rochester, MN 55905, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't