Source:http://linkedlifedata.com/resource/pubmed/id/14756690
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1-2
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| pubmed:dateCreated |
2004-2-3
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| pubmed:abstractText |
1. The effects of clomiphene (CLM) on cardiac outward K+ current components from rat isolated ventricular myocytes were investigated using the whole-cell patch-clamp technique. Clomiphene (10 micromol/L) significantly inhibited both peak (Ipeak) and end-pulse (Ilate) outward currents (elicited by a 500 msec voltage step from -40 to +50 mV in the presence of K+-containing intracellular and extracellular solutions) by approximately 37% (n = 6; P < 0.01) and 49% (n = 6; P < 0.01), respectively. In contrast, CLM had no effect on outward currents when K+-free solutions were used. 2. A double-pulse protocol and Boltzmann fitting were used to separate individual K+ current components on the basis of their voltage-dependent inactivation properties. At potentials positive to -80 mV, two inactivating transient outward components (Ito) and (IKx) and a non-inactivating steady state component (Iss) could be distinguished. 3. Clomiphene inhibited both Ito and Iss. The maximal block of Ito and Iss induced by CLM (100 micromol/L) was approximately 61% (n = 5) and 43% (n = 5) with IC50 values of 1.54 +/- 0.39 and 2.2 +/- 0.4 micromol/L, respectively. In contrast, the peak magnitude of IKx was unaltered by CLM, although its time-course of inactivation was accelerated. 4. Further experiments whereby myocytes were superfused with the vasoactive peptide endothelin (ET)-1 (20 nmol/L) revealed that CLM (10 micro mol/L) completely abolished the ET-1-sensitive component of Iss. 5. Our findings demonstrate, for the first time, the effects of CLM on distinct cardiac K+ current components and show that CLM modulates the voltage-gated K+ current components Ito and IKx and inhibits the steady state outward current Iss in rat ventricular myocytes.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Clomiphene,
http://linkedlifedata.com/resource/pubmed/chemical/Endothelin-1,
http://linkedlifedata.com/resource/pubmed/chemical/Estrogen Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Fertility Agents, Female,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channel Blockers,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Endothelin
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| pubmed:status |
MEDLINE
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| pubmed:issn |
0305-1870
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
31
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| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
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| pubmed:pagination |
86-95
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| pubmed:dateRevised |
2006-11-15
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| pubmed:meshHeading |
pubmed-meshheading:14756690-Algorithms,
pubmed-meshheading:14756690-Animals,
pubmed-meshheading:14756690-Clomiphene,
pubmed-meshheading:14756690-Electrophysiology,
pubmed-meshheading:14756690-Endothelin-1,
pubmed-meshheading:14756690-Estrogen Antagonists,
pubmed-meshheading:14756690-Fertility Agents, Female,
pubmed-meshheading:14756690-Heart Ventricles,
pubmed-meshheading:14756690-Male,
pubmed-meshheading:14756690-Membrane Potentials,
pubmed-meshheading:14756690-Myocytes, Cardiac,
pubmed-meshheading:14756690-Patch-Clamp Techniques,
pubmed-meshheading:14756690-Potassium,
pubmed-meshheading:14756690-Potassium Channel Blockers,
pubmed-meshheading:14756690-Potassium Channels,
pubmed-meshheading:14756690-Rats,
pubmed-meshheading:14756690-Rats, Wistar,
pubmed-meshheading:14756690-Receptors, Endothelin
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| pubmed:articleTitle |
Actions of the anti-oestrogen agent clomiphene on outward K+ currents in rat ventricular myocytes.
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| pubmed:affiliation |
Department of Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK.
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| pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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