Linked Life Data

11214600

Source:http://linkedlifedata.com/resource/pubmed/id/11214600

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-2-9
pubmed:abstractText
The effect of protein kinase C (PKC) on the Ca2+-activated K+ current (IK,Ca) in guinea-pig gastric myocytes was studied using the whole-cell voltage-clamp technique. At a holding potential of 0 mV, IK,Ca, recorded as spontaneous, transient, outwards currents (STOCs), was markedly inhibited, both in mean amplitude (54 +/- 5%) and frequency (60 +/- 8%) by 1 microM phorbol 12, 13 dibutyrate (PDBu, n = 6). These effects were antagonized by pretreatment with 10 nM bisindolylmaleimide I (n = 5), a selective inhibitor of PKC. The possibility that the inhibition of STOCs was due to direct channel inhibition by PKC was addressed using inside-out or open-cell-attached patch-clamp techniques, the latter established using beta-escin. PDBu did not alter the conductance or open probability of the KCa channel in any mode, suggesting that PKC does not inhibit the KCa channel directly. To study the involvement of the Na/Ca exchanger in the inhibition of STOCs by PDBu, its operation was prevented by replacing Na+ in the internal solution by tris(hydroxymethyl)aminomethane (TRIS) and external Na+ by equimolar K+ and Ca2+-activated inwards K+ currents recorded at a holding potential of 0 mV. Neither the mean amplitude (96 +/- 8%) nor the frequency of these currents was inhibited significantly by 1 microM PDBu (n = 5). Like PDBu, 5 microM 2-(2-[4-(4-nitrobenzyloxy)phenyl]ethyl) isothiourea methanesulphonate (KB-R7943), a selective inhibitor of the reverse mode Na/Ca exchanger, also inhibited the mean amplitude (45 +/- 6%) and frequency (26 +/- 2%) of STOCs at the holding potential of 0 mV (n=6). The results suggest that the suppression of STOCs by PKC is mediated by inhibition of the Na/Ca exchanger.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
441
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
417-24
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Protein kinase C suppresses spontaneous, transient, outwards K+ currents through modulation of the Na/Ca exchanger in guinea-pig gastric myocytes.
pubmed:affiliation
Department of Physiology and Biophysics, Seoul National University College of Medicine, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't