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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
16
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pubmed:dateCreated |
1985-8-29
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pubmed:abstractText |
A detailed kinetic study was performed to investigate the interaction of glucagon with receptors on freshly isolated hepatocytes. Competition binding assay results fit a mathematical expression for a single site noncooperative model of binding. Glucagon was shown to bind with first-order kinetics at six-hormone concentrations (0.02-0.50 nM) at 0 and 37 degrees C. The observed pseudo-first-order rate constants are directly proportional to the hormone concentration at 0 degree C, but display a downward deviation from linearity at 37 degrees C. Dissociation of glucagon exhibited biexponential character at 37 degrees C which was not seen at 0 degree C. The biphasic dissociation at 37 degrees C was resolved into rapid (t1/2 = 1.9 min) and slow (t1/2 = 27.7 min) components. The distribution of the total bound hormone between the rapidly and slowly dissociating complexes was not dependent upon the extent of receptor occupancy. The absolute quantity of rapidly dissociating hormone-receptor complexes was constant at all times examined; however, the fraction of slowly dissociating hormone-receptor complexes was found to increase with increasing incubation time. The results indicate that a homogeneous population of hepatic receptors undergoes a time-dependent, temperature-dependent conversion from one state to another in a two-stage sequential manner.
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pubmed:grant | |
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 |
Aug
|
pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
5
|
pubmed:volume |
260
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pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
9307-15
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2991239-Animals,
pubmed-meshheading:2991239-Binding, Competitive,
pubmed-meshheading:2991239-Glucagon,
pubmed-meshheading:2991239-Kinetics,
pubmed-meshheading:2991239-Liver,
pubmed-meshheading:2991239-Male,
pubmed-meshheading:2991239-Mathematics,
pubmed-meshheading:2991239-Models, Biological,
pubmed-meshheading:2991239-Rats,
pubmed-meshheading:2991239-Rats, Inbred Strains,
pubmed-meshheading:2991239-Receptors, Cell Surface,
pubmed-meshheading:2991239-Receptors, Glucagon,
pubmed-meshheading:2991239-Thermodynamics
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pubmed:year |
1985
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pubmed:articleTitle |
Kinetic identification of a two-state glucagon receptor system in isolated hepatocytes. Interconversion of homogeneous receptors.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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