Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The urine mutagenicity and excretion of 1-hydroxypyrene (1-OH PYR) in non-smoking psoriatic patients treated topically with coal-tar-based ointments were analysed in order to find the most appropriate procedure for monitoring occupational PAH exposure. The bacterial mutagenicity assays used were the plate incorporation, macro-scale fluctuation and microsuspension tests, all on Salmonella typhimurium strain TA98 in the presence of S9 mix and beta-glucuronidase. The sensitivities of the three assays in detecting mutagenic urinary PAH metabolites were compared. The efficiencies of XAD-2 and C18 resins for concentrating PAH urinary mutagens were evaluated in the microsuspension assay. The plate and fluctuation tests on XAD-2 urine extracts were shown to be insufficiently sensitive to detect low urinary levels of mutagens, being positive on urine samples with very high PAH metabolite content, estimated as more than 30 micrograms/g of creatinine of 1-OH PYR. The microsuspension assay on XAD-2 or, even better, on C18 urine extracts was very sensitive in detecting up to 5 micrograms/g of creatinine of 1-OH PYR. It therefore seems to be applicable to the biological monitoring of most occupational low exposures to coal tar.
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PMID:Sensitivity of different bacterial assays in detecting mutagens in urine of humans exposed to polycyclic aromatic hydrocarbons. 137 79

1-Nitropyrene (1-NP) and 2-nitrofluorene (2-NF), two of the most abundant nitro-substituted polycyclic aromatic hydrocarbons (nitro-PAH) present in combustion products such as diesel engine exhaust, were administered intraperitoneally to rats at a dose of 5 mg per animal. Urine samples, 1-NP and 2-NF were tested in the Ames assay using the newly developed Salmonella typhimurium strains YG1012 and YG1024 (overproducing O-acetyltransferase) and their parent strains TA1538 and TA98. In urine, collected over 3 periods of 24 h after administration, most of the mutagens appeared during the first 24 h. The mutagenicity was found to be a factor 2-30 higher in the YG strains when compared to the TA strains. Addition of S9 mix and rat liver cytosol both with and without beta-glucuronidase increased the mutagenicity of urine samples from 1-NP-treated rats. Addition of beta-glucuronidase revealed that a considerable part of the mutagenic metabolites of 1-NP and 2-NF were excreted as glucuronide conjugates. The increase in mutagenicity of urine samples from 2-NF-treated rats after the addition of rat liver cytosol referred to N,O-acyl transfer as a step in activating 2-NF to strong mutagens. The high sensitivity of the YG tester strains indicated that these strains might be used to explore environments where people are exposed to nitro-PAH, such as work places with diesel emission sources.
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PMID:Mutagenicity of urine from rats after 1-nitropyrene and 2-nitrofluorene administration using new sensitive Salmonella typhimurium strains YG1012 and YG1024. 187 Jun 28