Linked Life Data

9479017

Source:http://linkedlifedata.com/resource/pubmed/id/9479017

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1998-4-7
pubmed:abstractText
Three major ionic currents, Ca2+-dependent K+ current (IK-Ca), delayed rectifier type K+ current (Ikd) and Ca2+ current (ICa), were activated by depolarization under whole-cell clamp in single smooth muscle cells isolated from guinea-pig urinary bladder. Externally applied ruthenium red (RuR) reduced the amplitude of IK-Ca and ICa at 0 mV (IC50 values were 4.2 and 5.6 muM, respectively), but did not affect IKd. Spontaneous transient outward currents (STOCs) and caffeine-induced outward currents (Icaf) at -30 mV were reduced by external 10 muM RuR. When 10 muM RuR was added to the pipette solution, IK-Ca during depolarization, STOCs and Icaf significantly decreased with time. RuR did not change the unitary current amplitude of the large-conductance Ca2+-dependent K+ (BK) channels, but reduced the open probability of the channel under excised patch-clamp recording mode. RuR reduced the channel activity more effectively from the cytosolic face than from the other. This inhibition decreased when the cytosolic Ca2+ concentration was increased. These results indicate that RuR blocks BK and Ca2+ channels in urinary bladder smooth muscle cells. The decrease in IK-Ca, STOCs and Icaf by RuR is attributable to the direct inhibition of BK channel activity, probably in addition to the inhibition of Ca2+ release from storage sites. The direct inhibition of BK channel activity by RuR may be related to the interaction of RuR with the Ca2+-binding sites of the channel protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
435
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
645-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9479017-Animals, pubmed-meshheading:9479017-Caffeine, pubmed-meshheading:9479017-Calcium Channels, pubmed-meshheading:9479017-Delayed Rectifier Potassium Channels, pubmed-meshheading:9479017-Guinea Pigs, pubmed-meshheading:9479017-Ion Channels, pubmed-meshheading:9479017-Large-Conductance Calcium-Activated Potassium Channels, pubmed-meshheading:9479017-Membrane Potentials, pubmed-meshheading:9479017-Muscle, Smooth, pubmed-meshheading:9479017-Patch-Clamp Techniques, pubmed-meshheading:9479017-Potassium Channel Blockers, pubmed-meshheading:9479017-Potassium Channels, pubmed-meshheading:9479017-Potassium Channels, Calcium-Activated, pubmed-meshheading:9479017-Potassium Channels, Voltage-Gated, pubmed-meshheading:9479017-Ruthenium Red, pubmed-meshheading:9479017-Urinary Bladder
pubmed:year
1998
pubmed:articleTitle
Effects of ruthenium red on membrane ionic currents in urinary bladder smooth muscle cells of the guinea-pig.
pubmed:affiliation
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Nagoya City University, Nagoya 467, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't