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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
7
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pubmed:dateCreated |
1992-8-28
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pubmed:abstractText |
The mechanism by which benzidine induces bladder cancer in dog was evaluated by assessing metabolism of [3H]benzidine by dog liver slices and microsomes. Slices incubated with 0.05 mM [3H]benzidine exhibited a 32.5 min incubated with 0.05 mM [3H]benzidine exhibited a 32.5 min peak, which was also produced when microsomal incubations were supplemented with UDP-glucuronic acid. In contrast to microsomes, very little of the 32.5 min peak was produced with the 100,000 g supernatant fraction. Microsomal metabolism was increased 5-fold by pretreatment with Triton X-100. Very little activity was observed with rat microsomes in either the presence or absence of Triton X-100. This metabolite was also generated by incubating benzidine with glucuronic acid at 4 degrees C for 3 days. Thermospray MS identified this metabolite as benzidine N-glucuronide. At 37 degrees C, the t1/2 stability of purified N-glucuronide was 99, 25 and 3 min in dog urine adjusted to pH 7.3, 6.3 and 5.3 respectively. The N-glucuronide was quite stable at pH 9.3, in dog plasma, and in aprotic solvents for 4 h at 37 degrees C. Relative to benzidine, its N-glucuronide is weakly bound to plasma proteins but not more reactive with DNA. Thus, detoxification by liver provides a mechanism for accumulation of benzidine in acidic urine, uptake of benzidine into bladder epithelium, and activation of benzidine in bladder. The liver and N-glucuronidation play a potentially important role in the species specificity of benzidine carcinogenesis.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Benzidines,
http://linkedlifedata.com/resource/pubmed/chemical/DNA,
http://linkedlifedata.com/resource/pubmed/chemical/Glucuronates,
http://linkedlifedata.com/resource/pubmed/chemical/Glucuronosyltransferase,
http://linkedlifedata.com/resource/pubmed/chemical/Uridine Diphosphate Glucuronic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/benzidine
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pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0143-3334
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
13
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1235-40
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:1638692-Animals,
pubmed-meshheading:1638692-Benzidines,
pubmed-meshheading:1638692-DNA,
pubmed-meshheading:1638692-Dogs,
pubmed-meshheading:1638692-Glucuronates,
pubmed-meshheading:1638692-Glucuronosyltransferase,
pubmed-meshheading:1638692-Liver,
pubmed-meshheading:1638692-Mass Spectrometry,
pubmed-meshheading:1638692-Microsomes, Liver,
pubmed-meshheading:1638692-Uridine Diphosphate Glucuronic Acid,
pubmed-meshheading:1638692-Urinary Bladder Neoplasms
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pubmed:year |
1992
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pubmed:articleTitle |
Role of N-glucuronidation in benzidine-induced bladder cancer in dog.
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pubmed:affiliation |
VA Medical Center, St Louis, MO.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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