Linked Life Data

7536610

Source:http://linkedlifedata.com/resource/pubmed/id/7536610

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-5-25
pubmed:abstractText
Previous studies have revealed that expression of K+ channels in osteoclasts correlates with cell morphology and is influenced by interaction with the extracellular matrix. In this study, we investigated the electrophysiological properties of an outwardly rectifying K+ channel in rat and mouse osteoclasts using patch-clamp techniques. Cell-attached patch recordings revealed a channel of approximately 14 pS conductance that opened upon depolarization, and had a reversal potential close to that predicted for a K+ channel. Channel activity was transient; inactivation of ensemble currents, like that of whole-cell currents, occurred as a single exponential process. Both single-channel and macroscopic currents exhibited use-dependent inactivation in response to repetitive depolarizations. Two scorpion toxins, margatoxin and charybdotoxin, blocked this transient K+ channel, with half-maximal inhibition at 200 pM and 5 nM, respectively. In contrast, dendrotoxin (500 nM) had little effect. In summary, the outwardly rectifying K+ channel in osteoclasts resembles the Shaker-related K+ channel, Kv1.3. When membrane potential was recorded in whole-cell configuration, charybdotoxin (50 nM) caused a depolarization of 5 to 10 mV from resting levels of -50 mV or more positive; therefore this K+ channel contributes to the membrane potential of osteoclasts under some conditions. To investigate the molecular nature of osteoclast K+ channels, we performed RT-PCR on osteoclast RNA using primers for Kv1.3 and the inward rectifier, IRK1. mRNA encoded by Kv1.3 and IRK1 was detected and message identity confirmed by restriction enzyme digestion and sequence analysis. We conclude that osteoclasts exhibit, in addition to the previously described inward rectifier, an outwardly rectifying K+ conductance with properties of the Kv1.3. channel.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1060-6823
pubmed:author
pubmed:issnType
Print
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
281-93
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:7536610-Animals, pubmed-meshheading:7536610-Base Sequence, pubmed-meshheading:7536610-Cells, Cultured, pubmed-meshheading:7536610-Charybdotoxin, pubmed-meshheading:7536610-DNA Primers, pubmed-meshheading:7536610-Gene Expression, pubmed-meshheading:7536610-Mammals, pubmed-meshheading:7536610-Membrane Potentials, pubmed-meshheading:7536610-Mice, pubmed-meshheading:7536610-Mice, Inbred Strains, pubmed-meshheading:7536610-Molecular Sequence Data, pubmed-meshheading:7536610-Neurotoxins, pubmed-meshheading:7536610-Osteoclasts, pubmed-meshheading:7536610-Polymerase Chain Reaction, pubmed-meshheading:7536610-Potassium, pubmed-meshheading:7536610-Potassium Channel Blockers, pubmed-meshheading:7536610-Potassium Channels, pubmed-meshheading:7536610-Potassium Channels, Inwardly Rectifying, pubmed-meshheading:7536610-RNA, Messenger, pubmed-meshheading:7536610-Rats, pubmed-meshheading:7536610-Rats, Wistar, pubmed-meshheading:7536610-Scorpion Venoms
pubmed:year
1994
pubmed:articleTitle
Mammalian osteoclasts express a transient potassium channel with properties of Kv1.3.
pubmed:affiliation
Department of Physiology, University of Western Ontario, London, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't