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rdf:type |
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lifeskim:mentions |
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pubmed:dateCreated |
1997-8-1
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pubmed:abstractText |
1. Previous studies indicate that prostacyclin (PGI2) increases the activity of baroreceptor afferent fibres. The purpose of this study was to test the hypothesis that PGI2 inhibits Ca(2+)-activated K+ current (IK(Ca))in isolated baroreceptor neurones in culture. 2. Rat aortic baroreceptor neurones in the nodose ganglia were labelled in vivo by applying a fluorescent dye (DiI) to the aortic arch 1-2 weeks before dissociation of the neurones. Outward K+ currents in baroreceptor neurones evoked by depolarizing voltage steps from a holding potential of -40 mV were recorded using the whole-cell patch-clamp technique. 3. Exposure of baroreceptor neurones to the stable PGI2 analogue carbacyclin significantly inhibited the steady-state K+ current in a dose-dependent and reversible manner. The inhibition of K+ current was not caused indirectly by changes in cytosolic Ca2+ concentration. The Ca(2+)-activated K+ channel blocker charybdotoxin (ChTX, 10(-7) M) also inhibited the K+ current. In the presence of ChTX or in the absence of Ca2+, carbacyclin failed to inhibit the residual K+ current. Furthermore, in the presence of high concentrations of carbacyclin, ChTX did not cause further reduction of K+ current. 4. Carbacyclin-induced inhibition of IK(Ca) was mimicked by 8-bromo-cAMP and by activation of G-protein with GTP gamma S. The inhibitory effect of carbacyclin on IK(Ca) was abolished by GDP beta S, which blocks G-protein activation, and by a selective inhibitor of cAMP-dependent protein kinase, PKI5-24. 5. The results demonstrate that carbacyclin inhibits ChTX-sensitive IK(Ca) in isolated aortic baroreceptor neurones by a G-protein-coupled activation of cAMP-dependent protein kinase. This mechanism may contribute to the PGI2-induced increase in baroreceptor activity demonstrated previously.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1254872,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1317853,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1642895,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1646298,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1658550,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-174143,
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http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1848945,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1857986,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1878194,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-1976250,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2128200,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2177506,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2245501,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2420945,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2480673,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2504063,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2553198,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2578618,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2592953,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2842583,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2845815,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-2881323,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-3113327,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-3905049,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-490188,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-6122211,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-6270629,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-6421506,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-6985573,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7248805,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7511597,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7513840,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7515763,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7523613,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7539898,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7901264,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7904270,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7969497,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-7971738,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-8210183,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9192300-8396704
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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 |
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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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 |
1
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pubmed:volume |
501 ( Pt 2)
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
275-87
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:9192300-Animals,
pubmed-meshheading:9192300-Aorta, Thoracic,
pubmed-meshheading:9192300-Calcium,
pubmed-meshheading:9192300-Cells, Cultured,
pubmed-meshheading:9192300-Cyclic AMP-Dependent Protein Kinases,
pubmed-meshheading:9192300-Electric Stimulation,
pubmed-meshheading:9192300-Epoprostenol,
pubmed-meshheading:9192300-GTP-Binding Proteins,
pubmed-meshheading:9192300-Membrane Potentials,
pubmed-meshheading:9192300-Neurons, Afferent,
pubmed-meshheading:9192300-Nodose Ganglion,
pubmed-meshheading:9192300-Patch-Clamp Techniques,
pubmed-meshheading:9192300-Potassium Channels,
pubmed-meshheading:9192300-Pressoreceptors,
pubmed-meshheading:9192300-Prostaglandins, Synthetic,
pubmed-meshheading:9192300-Rats,
pubmed-meshheading:9192300-Rats, Sprague-Dawley,
pubmed-meshheading:9192300-Signal Transduction
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pubmed:year |
1997
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pubmed:articleTitle |
The prostacyclin analogue carbacyclin inhibits Ca(2+)-activated K+ current in aortic baroreceptor neurones of rats.
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