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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1-2
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pubmed:dateCreated |
1996-10-25
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pubmed:abstractText |
Properties and modulation of outward membrane currents in sympathetic neurons acutely dispersed from coeliac-superior mesenteric ganglia (C-SMG) of adult rats were examined using both the whole-cell variant of the patch-clamp technique and the perforated patch approach. Under voltage-clamp, four distinct outward currents were observed: a transient outward current (IA), a voltage-dependent sustained outward current consisting of a Ca(2+)-dependent component (IKCa) and a Ca(2+)-insensitive component (IKV), and a muscarinic agonist-sensitive outward current (IM). IA was isolated by digital subtraction, and characterized by very rapid activation at potentials more positive than -60 mV and by fast and complete voltage-dependent inactivation. Half inactivation potential (Vh) and slope factor (K) were -76 mV and 8.3 mV, respectively. IA was not affected by removal of external Ca2+, 1 mM tetraethylammonium ions, muscarinic agonists, or 8-bromo-cyclic AMP, but was suppressed by 4-aminopyridine (1 mM). Depolarizing pulses from of a holding potential of -50 or -60 mV to potentials more positive than -25 mV concomitantly activated two, independent sustained outward currents which decayed slowly; one exhibited voltage-dependent activation similar to the delayed rectifier current (IKV) and the other being triggered by Ca2+ influx into the cell (IKCa). The addition of tetraethylammonium ions (1 mM) strongly reduced the amplitude of the sustained outward currents. IM was characterized as a noninactivating time- and voltage-dependent outward current which activated at membrane potentials more positive than -60 mV and slowly turned off when the membrane was hyperpolarized back to -60 mV, and was suppressed by muscarinic agonists. The rank order of potency of the agonists tested was: oxotremorine > muscarine > bethanechol.
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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/4-Aminopyridine,
http://linkedlifedata.com/resource/pubmed/chemical/8-Bromo Cyclic Adenosine...,
http://linkedlifedata.com/resource/pubmed/chemical/Muscarinic Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Tetraethylammonium Compounds
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0006-8993
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
701
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1-12
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8925271-4-Aminopyridine,
pubmed-meshheading:8925271-8-Bromo Cyclic Adenosine Monophosphate,
pubmed-meshheading:8925271-Animals,
pubmed-meshheading:8925271-Electrophysiology,
pubmed-meshheading:8925271-Ganglia, Sympathetic,
pubmed-meshheading:8925271-Male,
pubmed-meshheading:8925271-Muscarinic Agonists,
pubmed-meshheading:8925271-Neurons,
pubmed-meshheading:8925271-Patch-Clamp Techniques,
pubmed-meshheading:8925271-Potassium Channels,
pubmed-meshheading:8925271-Rats,
pubmed-meshheading:8925271-Rats, Sprague-Dawley,
pubmed-meshheading:8925271-Tetraethylammonium Compounds
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pubmed:year |
1995
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pubmed:articleTitle |
Whole-cell and perforated patch recordings of four distinct K+ currents in acutely dispersed coeliac-superior mesenteric ganglia neurons of adult rats.
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pubmed:affiliation |
Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta 30912, USA.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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