rdf:type |
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lifeskim:mentions |
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pubmed:dateCreated |
1996-10-4
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pubmed:abstractText |
1. The effects of isosorbiddinitrate (ISDN) were tested on membrane currents and resting potential in Xenopus laevis oocytes which were either uninjected or injected with cRNA encoding for K+ channels from three distinct families (slowly activating IsK channels, delayed-rectifying Kv1.1 or inwardly rectifying IRK1 K+ channels). 2. In uninjected oocytes ISDN (1 mM) resulted in a decrease of the holding current at potentials more positive than -100 mV and in an increase at potentials below -100 mV. Increasing extracellular K+ to 100 mM shifted the reversal potential for ISDN-mediated effects to approximately -12 mV, suggesting an inhibition of a K+ conductance by ISDN. 3. In current clamp studies ISDN (1 mM) and Ba2+ (3 mM) depolarized cell membrane. ISDN and Ba2+ had no additive effects on membrane potential when applied simultaneously. In voltage clamp studies, corresponding results were observed for the effects of ISDN and Ba2+ on the holding current with an apparent K(m) of 0.21 and 0.08 mM, respectively. 4. In contrast to ISDN, the nitric oxide (NO) donors isosorbidmononitrate (ISMN) and S-nitrosocysteine (SNOC) had no effects on the holding currents in Xenopus oocytes. Moreover, the guanylate inhibitor LY 83583 did not affect ISDN-mediated holding current alterations, suggesting that ISDN acts independently of the second messenger NO. 5. ISDN inhibited exogenously expressed IsK channels with an apparent K(m) of 0.15 mM, but at 1 mM only weakly inhibited Kv1.1 and IRK1 channels. 6. It is concluded that ISDN inhibits an endogenous K+ conductance in Xenopus oocytes with a similar potency to that shown by expressed IsK channels. These effects are independent of the second messenger NO.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-1376999,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-1432714,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-1655304,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-1852778,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-2449311,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-2539643,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-2567594,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-2730656,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-3194754,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-6115052,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-7512692,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-7527230,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-7857264,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-7876101,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-7993632,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8815207-8037721
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/6-anilino-5,8-quinolinedione,
http://linkedlifedata.com/resource/pubmed/chemical/Aminoquinolines,
http://linkedlifedata.com/resource/pubmed/chemical/Barium,
http://linkedlifedata.com/resource/pubmed/chemical/Cysteine,
http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors,
http://linkedlifedata.com/resource/pubmed/chemical/Guanylate Cyclase,
http://linkedlifedata.com/resource/pubmed/chemical/Isosorbide Dinitrate,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Complementary,
http://linkedlifedata.com/resource/pubmed/chemical/S-Nitrosothiols,
http://linkedlifedata.com/resource/pubmed/chemical/S-nitrosocysteine,
http://linkedlifedata.com/resource/pubmed/chemical/Vasodilator Agents,
http://linkedlifedata.com/resource/pubmed/chemical/isosorbide-5-mononitrate
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0022-3751
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
15
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pubmed:volume |
491 ( Pt 3)
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
735-41
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:8815207-Aminoquinolines,
pubmed-meshheading:8815207-Animals,
pubmed-meshheading:8815207-Barium,
pubmed-meshheading:8815207-Cysteine,
pubmed-meshheading:8815207-Electrophysiology,
pubmed-meshheading:8815207-Enzyme Inhibitors,
pubmed-meshheading:8815207-Guanylate Cyclase,
pubmed-meshheading:8815207-Isosorbide Dinitrate,
pubmed-meshheading:8815207-Kinetics,
pubmed-meshheading:8815207-Oocytes,
pubmed-meshheading:8815207-Patch-Clamp Techniques,
pubmed-meshheading:8815207-Potassium Channels,
pubmed-meshheading:8815207-RNA, Complementary,
pubmed-meshheading:8815207-Rats,
pubmed-meshheading:8815207-S-Nitrosothiols,
pubmed-meshheading:8815207-Vasodilator Agents,
pubmed-meshheading:8815207-Xenopus laevis
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pubmed:year |
1996
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pubmed:articleTitle |
Effect of isosorbiddinitrate on exogenously expressed slowly activating K+ channels and endogenous K+ channels in Xenopus oocytes.
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pubmed:affiliation |
Institute of Physiology, Eberhard-Karls-Universität Tübingen, Germany.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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