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rdf:type |
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lifeskim:mentions |
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pubmed:dateCreated |
1990-3-22
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pubmed:abstractText |
1. The effect of the spider venom argiopine on L-glutamate-activated membrane channels of crayfish muscle was investigated using the patch-clamp technique. 2. When 10(-2) M-glutamate and 10(-9) M-argiopine were contained in the pipette solution of a cell-attached patch, bursts of openings of excitatory channels appeared after formation of the patch. These bursts ceased abruptly after variable periods of time in the range of 5 min. Higher concentrations of argiopine (up to 10(-6) M) blocked more rapidly, approximately in proportion to concentration. 3. The block of excitatory channels could be partially or completely reversed by hyperpolarizing the membrane by up to -190 mV from the resting potential. The time constant of the recovery of channel opening decreased with increasing hyperpolarization and was 2 ms with -160 mV hyperpolarization. Switching back from the hyperpolarized level to the resting potential, the time constant for the resulting block was about 3 s (10(-7) M-argiopine). Potential-dependent block by argiopine with similar characteristics was also observed in outside-out patches. 4. Up to argiopine concentrations of 10(-7) M the kinetics of channel openings and of bursts measured in pre-block periods or during reversal of the block by hyperpolarization were indistinguishable from controls. 5. When the potential-dependent block observed in the presence of 10(-6) M-argiopine and 10(-2) M-glutamate was reversed by hyperpolarization, additional short closings occurred during bursts. This 'flickering block' did not change burst length appreciably, but an additional open time component (tau = 0.1 ms) appeared and the average open time per burst was reduced. 6. At least two reaction steps seem necessary to model the behaviour of the potential-dependent block. The flickering block may be described as intermittent blocking of the channel which does not interfere with the reactions between glutamate and the channel.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-10432,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-13431862,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-190384,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-19431716,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2411346,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2414779,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2419552,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2436676,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2437524,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2437525,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2439957,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2460188,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-2465627,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-302330,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-306437,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-3655870,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-4152406,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-4541078,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-5046143,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-6099411,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-6127145,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-6270629,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-6270710,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-6276768,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-6310085,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2482886-6315161
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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 |
Dec
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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:volume |
419
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
569-87
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pubmed:dateRevised |
2010-9-10
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pubmed:meshHeading |
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pubmed:year |
1989
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pubmed:articleTitle |
Argiopine blocks glutamate-activated single-channel currents on crayfish muscle by two mechanisms.
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pubmed:affiliation |
Physiologisches Institut der Technischen Universität München, FRG.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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