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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1-2
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pubmed:dateCreated |
1993-4-16
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pubmed:abstractText |
We studied the hepatic processing and biliary excretion of metabolites of the radiolabeled cytostatic agent 5-fluoro,-2'-deoxy[6-3H]uridine (FUdR) and its lipophilic derivative FUdR-dipalmitate incorporated in liposomes. After intracardial injection in rats, free FUdR was cleared from the circulation within minutes. When FUdR or FUdR-dipalmitate was encapsulated in multilamellar vesicles (MLVs) composed of distearoylphosphatidylcholine/dipalmitoylphosphatidylglycerol (DSPC/DPPG/CHOL, 10:1), as expected, the clearance of 3H label was substantially delayed; incorporation of 50 mol% cholesterol in the liposomal bilayer caused a 2-fold further reduction in elimination rate. Incorporation of FUdR-dipalmitate in small unilamellar vesicles (SUV) of similar composition produced a several-fold further decrease in elimination rate: more than 40% of the injected dose was still circulating after 6 h. The plasma concentration of free FUdR after administration of liposomal FUdR-dipalmitate was below the detection limit (5 x 10(-8) M) at any time. Although only about 9% of the administered radioactivity was excreted into the bile within 48 h after injection of [3H]FUdR, a rapid initial excretion rate was observed (4% of the injected dose in the first 2 h). The bile-associated radioactivity was identified mainly as the catabolite alpha-fluoro-beta-alanine (FBAL), conjugated with the three major bile acid species present in rat bile, i.e., muricholic acid, cholic acid and chenodeoxycholic acid in a ratio of 1:3:1. Liposome incorporation of FUdR or FUdR-dipalmitate did not affect the nature of the excretory products but caused a significant decrease in the initial rate at which label appeared in the bile (< 2% in 6 h).
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Bile Acids and Salts,
http://linkedlifedata.com/resource/pubmed/chemical/Floxuridine,
http://linkedlifedata.com/resource/pubmed/chemical/Liposomes,
http://linkedlifedata.com/resource/pubmed/chemical/Tritium,
http://linkedlifedata.com/resource/pubmed/chemical/alpha-fluoro-beta-alanine,
http://linkedlifedata.com/resource/pubmed/chemical/beta-Alanine
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0006-3002
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
10
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pubmed:volume |
1176
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
43-50
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8452878-Animals,
pubmed-meshheading:8452878-Bile,
pubmed-meshheading:8452878-Bile Acids and Salts,
pubmed-meshheading:8452878-Floxuridine,
pubmed-meshheading:8452878-Liposomes,
pubmed-meshheading:8452878-Male,
pubmed-meshheading:8452878-Rats,
pubmed-meshheading:8452878-Rats, Wistar,
pubmed-meshheading:8452878-Tritium,
pubmed-meshheading:8452878-beta-Alanine
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pubmed:year |
1993
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pubmed:articleTitle |
Conversion of liposomal 5-fluoro-2'-deoxyuridine and its dipalmitoyl derivative to bile acid conjugates of alpha-fluoro-beta-alanine and their excretion into rat bile.
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pubmed:affiliation |
Laboratory of Physiological Chemistry, Groningen Institute for Drug Studies (GIDS), Groningen University, Netherlands.
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pubmed:publicationType |
Journal Article,
Comparative Study
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