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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
4
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pubmed:dateCreated |
1996-12-11
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pubmed:abstractText |
The present study was undertaken to characterize the export of cGMP from human erythrocytes at 37 degrees C. Inside-out membrane vesicles were exposed to cGMP and [3H]-cGMP in the presence and absence of 2 mmol l-1 ATP. In the absence of ATP, an equilibrium was reached within 15 min for the lowest tested concentration (0.65 mumol l-1), and the amount of cGMP in the vesicles was linearly correlated to the cGMP concentrations in the incubate. These observations suggest that the ATP-independent process represents passive diffusion or non-saturated binding to membrane components. In the presence of ATP, cGMP accumulated linearly during the test period (up to 120 min) and the transport into the inside-out vesicles was dependent on both low- and high-Km transport. The kinetic parameters for the low-Km process were determined after 5 and 120 min, the Km values being 4.6 (SD 1.9) and 4.7 (SD 1.1) mumol l-1 (n = 3), respectively. The corresponding Vmax values were 400 (SD 50) and 440 (SD 70) fmol mg-1 min-1. The high-Km process was characterized by Km = 170 (SD 50) mumol-1 and Vmax = 1610 (SD 280) fmol mg-1 min-1 (n = 5). The present data demonstrate an ATP-requiring saturable transport system for cGMP in human erythrocytes.
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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 |
Jul
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pubmed:issn |
0036-5513
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
56
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pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
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pubmed:pagination |
289-93
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8837234-Adenosine Triphosphate,
pubmed-meshheading:8837234-Biological Transport,
pubmed-meshheading:8837234-Chromatography, Thin Layer,
pubmed-meshheading:8837234-Cyclic GMP,
pubmed-meshheading:8837234-Erythrocyte Membrane,
pubmed-meshheading:8837234-Humans,
pubmed-meshheading:8837234-Kinetics
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pubmed:year |
1996
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pubmed:articleTitle |
Export of guanosine 3',5'-cyclic monophosphate (cGMP) from human erythrocytes characterized by inside-out membrane vesicles.
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pubmed:affiliation |
Department of Pharmacology, University of Tromsø, Norway.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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