rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1
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pubmed:dateCreated |
1990-4-26
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pubmed:abstractText |
The effects of polymyxin B, a cyclic polycationic peptide antibiotic, on the binding of thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor agonists and antagonists to the putative human platelet TXA2/PGH2 receptor have been determined. Crude membranes were prepared from washed human platelets and the binding of [125I]-PTA-OH, a TXA2/PGH2 receptor antagonist, was used as a ligand to characterize the effects of polymyxin B on agonist and antagonist binding. Polymyxin B produced a concentration-dependent decrease in the IC50 values for the TXA2/PGH2 agonist, U46619, in radioligand competition binding assays. Polymyxin B also decreased the IC50 values of the TXA2/PGH2 agonist ONO 11113 from 75 +/- 11 nM to 38 +/- 2.5 nM and the TXA2/PGH2 receptor antagonist SQ29548 from 60 +/- 14 nM to 20 +/- 2.3 nM. The Kd for [125I]-PTA-OH was also reduced by polymyxin B from 107 +/- 10 nM to 76 +/- 6 nM but it had no effect on the maximum number of binding sites (Bmax). Polymyxin B had no significant effect on the binding affinity of U46619 in intact washed human platelets. These results raise the possibility that polymyxin B can alter the conformational state of the TXA2/PGH2 receptor when it is in a crude membrane fraction but not in intact platelets.
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pubmed:grant |
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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 |
http://linkedlifedata.com/resource/pubmed/chemical/1-(5-Isoquinolinesulfonyl)-2-Methylp...,
http://linkedlifedata.com/resource/pubmed/chemical/15-Hydroxy-11 alpha,9...,
http://linkedlifedata.com/resource/pubmed/chemical/Hydrazines,
http://linkedlifedata.com/resource/pubmed/chemical/I-PTA-OH,
http://linkedlifedata.com/resource/pubmed/chemical/Isoquinolines,
http://linkedlifedata.com/resource/pubmed/chemical/Piperazines,
http://linkedlifedata.com/resource/pubmed/chemical/Polymyxin B,
http://linkedlifedata.com/resource/pubmed/chemical/Polymyxins,
http://linkedlifedata.com/resource/pubmed/chemical/Prostaglandin Endoperoxides,
http://linkedlifedata.com/resource/pubmed/chemical/Prostaglandin Endoperoxides...,
http://linkedlifedata.com/resource/pubmed/chemical/Prostaglandins H,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase Inhibitors,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Prostaglandin,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Thromboxane,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Thromboxane A2...,
http://linkedlifedata.com/resource/pubmed/chemical/SQ 29548,
http://linkedlifedata.com/resource/pubmed/chemical/STA 2,
http://linkedlifedata.com/resource/pubmed/chemical/Thromboxane A2
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pubmed:status |
MEDLINE
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pubmed:issn |
0934-9820
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
1
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
41-4
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pubmed:dateRevised |
2009-2-14
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pubmed:meshHeading |
pubmed-meshheading:2856171-1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine,
pubmed-meshheading:2856171-15-Hydroxy-11 alpha,9...,
pubmed-meshheading:2856171-Blood Platelets,
pubmed-meshheading:2856171-Cell Membrane,
pubmed-meshheading:2856171-Humans,
pubmed-meshheading:2856171-Hydrazines,
pubmed-meshheading:2856171-Isoquinolines,
pubmed-meshheading:2856171-Piperazines,
pubmed-meshheading:2856171-Polymyxin B,
pubmed-meshheading:2856171-Polymyxins,
pubmed-meshheading:2856171-Prostaglandin Endoperoxides,
pubmed-meshheading:2856171-Prostaglandin Endoperoxides, Synthetic,
pubmed-meshheading:2856171-Prostaglandins H,
pubmed-meshheading:2856171-Protein Kinase Inhibitors,
pubmed-meshheading:2856171-Receptors, Prostaglandin,
pubmed-meshheading:2856171-Receptors, Thromboxane,
pubmed-meshheading:2856171-Receptors, Thromboxane A2, Prostaglandin H2,
pubmed-meshheading:2856171-Thromboxane A2
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pubmed:year |
1988
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pubmed:articleTitle |
Polymyxin B increases TXA2/PGH2 agonist and antagonist affinities in human platelet membranes.
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pubmed:affiliation |
Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston 29425.
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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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