Source:http://linkedlifedata.com/resource/pubmed/id/11547340
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
3
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| pubmed:dateCreated |
2001-9-7
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| pubmed:abstractText |
K+ secretion in strial marginal cells (SMC) of stria vascularis (SV) is stimulated by beta1-adrenergic receptors. The aim of the present study was to determine, whether SMC from the gerbil inner ear contain muscarinic receptors that inhibit K+ secretion. Receptors were identified with pharmacological tools in functional studies where K+ secretion was monitored as transepithelial current (Isc). The cytosolic Ca2+ concentration ([Ca2+]i) was measured as fluo-4 fluorescence and cAMP production with a colorimetric immunoassay. Further, receptors were identified in SV as transcripts by cloning and sequencing of reverse-transcriptase polymerase chain reaction (RT-PCR) products. The cholinergic receptor agonist carbachol (CCh) caused a transient increase in [Ca2+]i with a half-maximal concentration value (EC50) of (5 +/- 6) x 10(-6) m (n = 29) and a decrease in basal and stimulated cAMP production. Apical CCh had no effect on Isc but basolateral CCh caused a transient increase in Isc with an EC50 of (3 +/- 1) x 10(-6) m and a sustained decrease of Isc with an EC50 of (1.2 +/- 0.2) x 10(-5) m (n = 129). The effects of CCh on Isc and [Ca2+]i were inhibited in the presence of muscarinic antagonist 10(-6) m atropine. Further, the muscarinic antagonists pirenzipine, methoctramine and para-fluoro-hexahydo-sila-defenidol (pFHHSiD) inhibited the CCh-induced transient increase of Isc with affinity constants (KDB) of 3 x 10(-8) m (pKDB = 7.54 +/- 0.19, n = 17), 2 x 10(-6) m (pKDB = 5.71 +/- 0.26, n = 19) and 2 x 10(-8) m (pKDB = 7.65 +/- 0.28, n = 19) and the sustained decrease of Isc with KDB of 7 x 10(-8) m (pKDB = 7.05 +/- 0.09, n = 33), 6 x 10(-6) m (pKDB = 5.21 +/- 0.13, n = 23), 5 x 10(-8) m (pKDB = 7.34 +/- 0.13, n = 31), respectively. RT-PCR of total RNA isolated from SV using primers specific for the M1-M5 muscarinic receptors revealed products of the predicted sizes for the M3- and M4- but not the M1-, M2- and M5-muscarinic receptor subtypes. Sequence analysis confirmed that amplified cDNA fragments encoded gene-specific nucleotide sequences. These results suggest that K+ secretion in SMC is under the control of M3- and M4-muscarinic receptors that may be located in the basolateral membrane of strial marginal cells.
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| pubmed:grant | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/4-fluorohexahydrosiladifenidol,
http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic beta-Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/Atropine,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Carbachol,
http://linkedlifedata.com/resource/pubmed/chemical/Cholinergic Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP,
http://linkedlifedata.com/resource/pubmed/chemical/Diamines,
http://linkedlifedata.com/resource/pubmed/chemical/Isoproterenol,
http://linkedlifedata.com/resource/pubmed/chemical/Muscarinic Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Parasympatholytics,
http://linkedlifedata.com/resource/pubmed/chemical/Piperidines,
http://linkedlifedata.com/resource/pubmed/chemical/Pirenzepine,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Muscarinic,
http://linkedlifedata.com/resource/pubmed/chemical/methoctramine
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| pubmed:status |
MEDLINE
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| pubmed:month |
Aug
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| pubmed:issn |
0022-2631
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
1
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| pubmed:volume |
182
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
171-81
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| pubmed:dateRevised |
2007-11-14
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| pubmed:meshHeading |
pubmed-meshheading:11547340-Adrenergic beta-Agonists,
pubmed-meshheading:11547340-Animals,
pubmed-meshheading:11547340-Atropine,
pubmed-meshheading:11547340-Calcium,
pubmed-meshheading:11547340-Carbachol,
pubmed-meshheading:11547340-Cholinergic Agonists,
pubmed-meshheading:11547340-Cloning, Molecular,
pubmed-meshheading:11547340-Cyclic AMP,
pubmed-meshheading:11547340-Diamines,
pubmed-meshheading:11547340-Dose-Response Relationship, Drug,
pubmed-meshheading:11547340-Gerbillinae,
pubmed-meshheading:11547340-Isoproterenol,
pubmed-meshheading:11547340-Muscarinic Antagonists,
pubmed-meshheading:11547340-Parasympatholytics,
pubmed-meshheading:11547340-Piperidines,
pubmed-meshheading:11547340-Pirenzepine,
pubmed-meshheading:11547340-Potassium,
pubmed-meshheading:11547340-Receptors, Muscarinic,
pubmed-meshheading:11547340-Reverse Transcriptase Polymerase Chain Reaction,
pubmed-meshheading:11547340-Stria Vascularis
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| pubmed:year |
2001
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| pubmed:articleTitle |
Muscarinic receptors control K+ secretion in inner ear strial marginal cells.
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| pubmed:affiliation |
Cell Physiology Laboratory, Anatomy & Physiology Department Kansas State University, 1600 Dension Ave., Manhattan KS 66506, USA.
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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