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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1994-6-1
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pubmed:abstractText |
The dorsal root ganglion-neuroblastoma cell line ND7-23 expresses low-voltage-activated calcium channel currents, and also expresses high-voltage-activated currents in about 50% of differentiated cells. Calcium channel currents were recorded with Ba2+ as the charge carrier. Low-voltage-activated currents were maximally activated at -30 mV and completely inactivated at holding potentials of -60 to -50 mV. omega-Conotoxin GVIA produced a reversible inhibition of low-voltage-activated currents, whereas the inhibition of high-voltage-activated current was largely irreversible. Dihydropyridine antagonists did not inhibit low-voltage-activated currents, whereas they inhibited a sustained, high-voltage-activated current. Low-voltage-activated currents were inhibited to a greater extent than high-voltage-activated currents by Ni2+ (100 microM) and by phenytoin (10 microM). Bradykinin (0.1 microM), baclofen (2 microM) and internal guanosine-5'-O-3-thiotriphosphate (100 microM) inhibited low-voltage-activated currents without affecting their kinetics of activation. Two classes of low-voltage-activated current were distinguished by their kinetics of inactivation. In the majority of cells, currents were slowly inactivating with a time-constant of inactivation of about 50 ms. They also exhibited a sustained component to the current, representing about 20% of the peak current. This component could be distinguished pharmacologically from high-voltage-activated current. The remainder of cells expressed a rapidly and completely inactivating current, with a time-constant of inactivation of about 20 ms. Two distinct single channel currents were observed in these cells, from cell-attached patch measurements, one had a single channel conductance of 7.9 pS, and the ensemble average current showed some inactivation. It is likely that this channel subtype underlies the low-voltage-activated current. The other showed long openings in the presence of a dihydropyridine agonist, had a conductance of 23.1 pS, and was non-inactivating.
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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/Ammonium Chloride,
http://linkedlifedata.com/resource/pubmed/chemical/Baclofen,
http://linkedlifedata.com/resource/pubmed/chemical/Bradykinin,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channel Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channel Blockers,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Dihydropyridines,
http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine 5'-O-(3-Thiotriphosphate),
http://linkedlifedata.com/resource/pubmed/chemical/Neurotransmitter Agents,
http://linkedlifedata.com/resource/pubmed/chemical/Nicotinic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Oxadiazoles,
http://linkedlifedata.com/resource/pubmed/chemical/PN 202-791,
http://linkedlifedata.com/resource/pubmed/chemical/Peptides,
http://linkedlifedata.com/resource/pubmed/chemical/Phenytoin,
http://linkedlifedata.com/resource/pubmed/chemical/omega-Conotoxin GVIA
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pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0306-4522
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
58
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
539-52
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pubmed:dateRevised |
2009-9-29
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pubmed:meshHeading |
pubmed-meshheading:7909587-Ammonium Chloride,
pubmed-meshheading:7909587-Animals,
pubmed-meshheading:7909587-Baclofen,
pubmed-meshheading:7909587-Bradykinin,
pubmed-meshheading:7909587-Calcium Channel Agonists,
pubmed-meshheading:7909587-Calcium Channel Blockers,
pubmed-meshheading:7909587-Calcium Channels,
pubmed-meshheading:7909587-Cell Differentiation,
pubmed-meshheading:7909587-Cell Line,
pubmed-meshheading:7909587-Dihydropyridines,
pubmed-meshheading:7909587-Electrophysiology,
pubmed-meshheading:7909587-GTP-Binding Proteins,
pubmed-meshheading:7909587-Ganglia, Spinal,
pubmed-meshheading:7909587-Guanosine 5'-O-(3-Thiotriphosphate),
pubmed-meshheading:7909587-Mice,
pubmed-meshheading:7909587-Neurotransmitter Agents,
pubmed-meshheading:7909587-Nicotinic Acids,
pubmed-meshheading:7909587-Oxadiazoles,
pubmed-meshheading:7909587-Peptides,
pubmed-meshheading:7909587-Phenytoin,
pubmed-meshheading:7909587-Rats,
pubmed-meshheading:7909587-Tumor Cells, Cultured,
pubmed-meshheading:7909587-omega-Conotoxin GVIA
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pubmed:year |
1994
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pubmed:articleTitle |
Low- and high-voltage-activated calcium channel currents and their modulation in the dorsal root ganglion cell line ND7-23.
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pubmed:affiliation |
Department of Pharmacology, Royal Free Hospital School of Medicine, London, U.K.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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