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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1996-2-21
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pubmed:abstractText |
Using the technique of vanadate-facilitated [3H]ouabain binding we have developed a simple and reliable assay for measuring the concentration of [3H]ouabain binding sites in small fresh or frozen biopsies of rumen epithelium papillae. In bovine and ovine rumen epithelium obtained from the cranio-ventral rumen sac the concentration of [3H]ouabain binding sites was 1.6-4.9 nmol g dry wt-1 (n = 32) and 3.7-5.2 nmol g dry wt-1 (n = 6), respectively. When incubated in oxygenated Krebs-Ringer bicarbonate buffer fresh biopsies of rumen epithelium maintained a high K+ and low Na+ content for at least 6 h. Na+ loading of the biopsies induced about 20-fold increase of the Na+, K(+)-pump activity based on measurement of ouabain suppressible net [86Rb+] influx. The ouabain suppressible net influx of [86Rb+] measured in Na+ loaded biopsies showed a close correlation to the [3H]ouabain binding capacity (r = 0.80, P < 0.01) and corresponded to 47 +/- 2% (n = 9) of the theoretical maximum flux rate. The ouabain suppressible net influx of K+ and [86Rb+] were linearly related (r = 0.73; P < 0.001). The net Na+ efflux was 1.21 times the net K+ influx. It is concluded that rumen epithelium has a large capacity for active Na+/K+ transport and that there is agreement between the concentration of [3H]ouabain binding sites in the epithelium and the ouabain suppressible rate of net [86Rb+] influx in Na+ loaded biopsies in spite of some uncertainty about the maximum turnover number of the Na+, K(+)-pump in rumen epithelium.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0001-6772
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
155
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
67-76
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pubmed:dateRevised |
2007-11-15
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pubmed:meshHeading |
pubmed-meshheading:8553879-Absorption,
pubmed-meshheading:8553879-Animals,
pubmed-meshheading:8553879-Biopsy,
pubmed-meshheading:8553879-Cattle,
pubmed-meshheading:8553879-Epithelium,
pubmed-meshheading:8553879-Potassium,
pubmed-meshheading:8553879-Rumen,
pubmed-meshheading:8553879-Sheep,
pubmed-meshheading:8553879-Sodium,
pubmed-meshheading:8553879-Sodium-Potassium-Exchanging ATPase
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pubmed:year |
1995
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pubmed:articleTitle |
Measurement of the total concentration of functional Na+, K(+)-pumps in rumen epithelium.
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pubmed:affiliation |
Institute of Physiology, University of Aarhus, Denmark.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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