Source:http://linkedlifedata.com/resource/pubmed/id/16664165
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
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| pubmed:dateCreated |
2010-6-29
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| pubmed:abstractText |
We have investigated the effects of hyperpolarization and depolarization, and the presence of K(+) and/or Ca(2+), on (22)Na(+) influx into corn (Zea mays L.) root segments. In freshly excised root tissue which is injured, Na(+) influx is unaffected by hyperpolarization with fusicoccin, or depolarization with uncoupler (protonophore), or by addition of K(+). However, added Ca(2+) suppresses Na(+) influx by 60%. In washed tissue which has recovered, Na(+) influx is doubled over that of freshly excised tissue, and the influx is increased by fusicoccin and suppressed by uncoupler. This energy-linked component of Na(+) influx is completely eliminated by low concentrations of K(+), leaving the same level and kind of Na(+) influx seen in freshly excised roots. The K(+)-sensitive energy linkage appears to be by the carrier for active K(+) influx. Calcium is equally inhibitory to Na(+) influx in washed as in fresh tissue. Other divalent cations are only slightly less effective. Net Na(+) uptake was about 25% of (22)Na(+) influx, but proportionately the response to K(+) and Ca(2+) was about the same.The constancy of K(+)-insensitive Na(+) influx under conditions known to hyperpolarize and depolarize suggests that if Na(+) transport is by means of a voltage-sensitive channel, the rise or fall of channel resistance must be proportional to the rise or fall in potential difference. The alternative is a passive electroneutral exchange of (22)Na(+) for endogenous Na(+). The data suggest that an inwardly directed Na(+) current is largely offset by an efflux current, giving both a small net uptake and isotopic exchange.
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| pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16653734,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16655470,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16655536,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16656509,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16657889,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16658538,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16658977,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16660707,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16662381,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16662471,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16663165,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-16663854,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-6093255,
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664165-6265962
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Apr
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| pubmed:issn |
0032-0889
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
77
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
930-4
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| pubmed:dateRevised |
2010-9-14
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| pubmed:year |
1985
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| pubmed:articleTitle |
Controls on na influx in corn roots.
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| pubmed:affiliation |
Department of Plant Biology, University of Illinois, Urbana, Illinois 61801.
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| pubmed:publicationType |
Journal Article
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