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

Two monoclonal antibodies (10C10 and 4D5) have been developed from the spleen cells of Balb/c mice immunized with 6-aminobenzo[a]pyrene covalently coupled to bovine serum albumin. These antibodies have been used in an immunoassay for the detection of benzo[a]pyrene and its metabolites in mouse urine. The antibodies were characterized in terms of sensitivity and specificity by competitive enzyme-linked immunosorbent assay (ELISA). With both antibodies, 50% inhibition of antibody binding is at 4 pmol of BP. The antibodies also cross-react with a number of BP metabolites as well as with several other polycyclic aromatic hydrocarbons (PAHs) including pyrene, 1-aminopyrene, and 7,12-dimethylbenz[a]anthracene but with different sensitivities. These results suggest that this assay will detect multiple PAH metabolites in urine. To test the assay on biological samples, mice were treated with [3H]BP, and urine was collected and digested with beta-glucuronidase and aryl sulfatase. Several methods were used to isolate BP and its metabolites from the urine, including ethyl acetate extraction, Sep-pak C18 cartridge chromatography, XAD2 resin chromatography, and immunoaffinity chromatography with antibody 4D5. Analysis of the urine extracts with antibody 4D5 gave 50% inhibition at 12-15 pmol of metabolites. Thus, quantitation of metabolites in this sample by competitive ELISA against a standard curve of BP would have underestimated actual metabolite levels by about 70%. This assay will be applied to the analysis of urines from individuals with environmental or occupational exposure. Since humans are usually exposed to BP in complex mixtures of PAHs, multiple metabolites may be present in the urine, making absolute quantitation difficult. This assay should thus serve as a general indicator of exposure to this class of chemicals.
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PMID:Immunologic methods for the detection of benzo[a]pyrene metabolites in urine. 213 77

Milk and plasma levels of zearalenone (ZEN), alpha-zearalenol (alpha-ZEL), beta-zearalenol (beta-ZEL) and conjugated metabolites were determined after feeding lactating cows with ZEN. In those instances where ZEN and alpha- and beta-ZEL were detected in milk or plasma, they occurred only as conjugates hydrolysable by treatment with a mixture of beta-glucuronidase and aryl sulfatase. With studies where 50 or 165 mg was fed daily to three cows for 21 day periods, neither dosage showed the presence of ZEN or metabolites in either milk or plasma (detection limits: milk, 0.5 ng/ml, ZEN, alpha-ZEL; 1.5 ng/ml, beta-ZEL; plasma, 2-3 times higher). A dose of 544.5 mg zearalenone per day given to a single cow for 21 days yielded maximum concentrations of only 2.5 ng ZEN/ml and 3.0 ng alpha-ZEL/ml in the milk. In plasma, up to 3 ng ZEN/ml could be detected during the initial 4 days of treatment. At a dose of 1.8 g of zearalenone given over a one day feeding period, maximum milk levels of 4.0 ng ZEN/ml, 1.5 ng alpha-ZEL/ml, and 4.1 ng beta-ZEL/ml were observed during the initial 2 days; corresponding maximum levels after a one day dose of 6.0 g zearalenone were 6.1, 4.0 and 6.6 ng/ml milk on days 2-3. In plasma, peak ZEN concentrations (9 and 13 ng/ml at the lower and higher one-day doses, respectively) occurred 12 hr after initial dosing, and declined to negligible levels by days 5-7. Neither alpha- nor beta-ZEL were detected in plasma. Since measurable levels required very high oral doses of ZEN, milk would not normally pose a human health hazard as a result of feeding rations containing ZEN to lactating dairy cows.
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PMID:Minimal transmission of zearalenone to milk of dairy cows. 214 Mar 83

We briefly review some biochemical aspects of benign breast disease (BBD), mainly focusing on free and conjugate estrogen content of breast cyst fluid (BCF), also in relation to cyst type. Evidence is reported that high K(+)-type I-cysts clearly associate with low Cl- levels and accumulate significantly higher quantities of dehydroepiandrosterone sulfate (DHAS) and estrone-3-sulfate (E1S). In spite of the limited number of cases, both increasing DHAS and E1S levels correlate with the increment of K+ to Na+ ratio. A positive correlation was also found between DHAS and E1S. Using electrochemical detection (ECD) on-line to high performance liquid chromatography (HPLC) in the reverse phase mode, we also studied the free estrogen profile. We observed that in type I BCF there are significantly increased amounts of free estrone (E1). The E1S to E1 ratio was significantly different in the two cyst subpopulations; again, a positive correlation was found between free and sulfated E1 (r = 0.820, p less than 10(-6). This last, together with other experimental observations, allows us to hypothesize that in BCF a main pathway of steroids should be E1S----E1. Besides, high specific activity of sulfatase, as well as beta-glucuronidase enzymes, has been demonstrated for BBD. Preliminary information is also reported concerning the BCF pattern of free estrogens, including the highly polar ones, i.e., catecholestrogens (CCE) and the parent methoxy (MeO) conjugates, which represent, in BCF, a predominant portion of all free estrogens. Both CCE levels and ratios appear unevenly distributed in the two different cyst types. In addition, some BCFs show very high concentrations of 16 alpha-OH-E1. Further studies are needed to answer the main question: whether estrogen patterns could represent additive parameters to further categorize breast cystic disease (BCD) or whether they are of minor interest to determine patients' risk of developing breast cancer.
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PMID:Steroid patterns of benign breast disease. 214 55

Following analysis by reversed-phase HPLC, a previously uncharacterized metabolite of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was found in the urine of A/J mice treated with NNK. Treatment with beta-glucuronidase converted the metabolite to a peak that co-eluted with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). Treatment with sulfatase or beta-glucuronidase plus saccharic acid 1,4-lactone did not change the retention time of the metabolite. These data suggested that the unknown metabolite was a glucuronic acid conjugate of NNAL. Upon isolation and purification of larger quantities of the metabolite from the urine of A/J mice, CD-1 mice and F344 rats, 1H and 13C NMR and MS confirmed that the unknown metabolite was 4-(methylnitrosamino)-1-(3-pyridyl)-1-butyl beta-D-glucopyranosiduronic acid (NNAL Glu). To determine the quantitative relationship between NNK dose and NNAL Glu production and to compare the importance of glucuronidation relative to other metabolic pathways, [5-3H]NNK was administered to F344 rats and A/J mice at doses of 500-0.005 mumol/kg. At 500 mumol/kg, NNAL Glu accounted for 22% of the total urinary excretion of NNK in A/J mice, and for 8% in F344 rats 48 h after dosing. The proportions of excreted glucuronide and NNAL decreased with diminishing doses of NNK, yielding undetectable levels of each metabolite in both mice and rats at a dose of 0.005 mumol/kg NNK. Since substantial amounts of metabolites formed via alpha-hydroxylation and N-oxidation pathways were observed at the lower doses of NNK, these data demonstrate that NNAL glucuronidation is a quantitatively unimportant metabolic pathway at low doses of NNK.
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PMID:Characterization of a glucuronide metabolite of 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its dose-dependent excretion in the urine of mice and rats. 220 95

The metabolism of scopolamine and glycopyrrolate was studied in 11 healthy parturients undergoing cesarean section. After a single intramuscular injection of scopolamine (5 micrograms/kg, n = 7) or glycopyrrolate (6 micrograms/kg, n = 4), the concentrations of the drugs in the urine were determined up to 8-12 h using a radioreceptor assay. This assay measures scopolamine and glycopyrrolate with their possible active metabolites. The effect of beta-glucuronidase and sulfatase incubation on the drug concentrations was also studied. The concentrations of scopolamine and/or its active metabolites were on the average 7 times higher after incubation indicating that beta-glucuronide or sulfate conjugation is an important metabolic pathway for scopolamine. On the contrary, the glycopyrrolate concentrations increased only slightly between 1 and 3 hours after the drug injection. Thus, beta-glucuronide or sulfate conjugation plays only a minor part in the metabolism of glycopyrrolate.
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PMID:beta-Glucuronide and sulfate conjugation of scopolamine and glycopyrrolate. 227 10

Kinetic studies of the histochemical and histoenzymatic behavior of rabbit pancreatic parenchymas were performed 5, 30 and 90 days after Wirsung duct ligation. In control pancreas, some enzyme activities (EA) were more prominent in Langerhans islets [glucose-6-phosphatase, glucose-6-phosphate dehydrogenase (DH), isocitrate DH, glycerol-3-phosphate DH, NADPH DH], others were strongly marked in acini and ducts (alkaline phosphatase, beta-glucuronidase, acid esterase aryl-sulfatase). Histochemical and enzyme abnormalities observed in experimental rabbits reflect the post-ligation degenerative and reactive processes in both exocrine and endocrine pancreas: (1) the decrease in Krebs cycle and pentose pathway linked EA and the increased lysosomal and acid phosphatase EA reflect early (day 5) degeneration and necrosis of islets and acini (day 30); (2) proliferative processes in developed ductal epithelia are shown by an increase in both glycolytic and lysosomal EA (days 30 and 90); (3) connective tissue neogenesis and interstitial fibrosis occurred as shown by activated beta-glucuronidase, aryl-sulfatase, alkaline phosphatase and increased ribonucleoproteins and glycoaminoglycans contents (day 30); (4) on day 90, the neoformed cell clusters presenting glucose-6-phosphatase positivity (B-cell marker) are seen in the pancreas remnant. At the same time, blood insulin level increases correlated with a decrease of hyperglycemia.
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PMID:Cell features in pancreas of prediabetic and diabetic rabbits after Wirsung duct ligation. Histochemical and histoenzymatic studies. 233 24

A method has been developed to quantify three lidocaine metabolites, N-ethylglycyl-2,6-xylidide (MEGX), glycyl-2,6-xylidide (GX), and 4-hydroxy-2,6-xylidine (4-OH-XY), and their conjugates in pooled human urine using enzymic hydrolysis. The commonly used enzymes, pure beta-glucuronidase, sulfatase, and a mixture of the two, were tested for their efficiencies in hydrolyzing the conjugates. Initially, it was found that 4-OH-XY was highly unstable after it was released from conjugates by beta-glucuronidase and the enzyme mixture. This problem was corrected by purging the sample with nitrogen prior to incubation. It has been determined that 4-OH-XY is present in human urine exclusively as its glucuronide. The percentage of MEGX in free and in conjugated forms (glucuronide, sulfate, and others) are 44.9 +/- 6.8, 16.6 +/- 4.5, 6.6 +/- 1.8, and 31.9 +/- 4.4, respectively. GX was present mostly in the free form (90.6 +/- 10.5%).
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PMID:Quantification of three lidocaine metabolites and their conjugates. 236 19

Urinary metabolites and biological half-life of chlorpyrifos (O, O-diethyl-O-3,5,6-trichloro-2-pyridinyl phosphorothioate) were investigated. Male Wistar rats weighing 200 g were intraperitoneally injected with chlorpyrifos at a level of 0.2 mmol/kg body weight. Both chlorpyrifos and 3,5,6-trichloro-2-pyridinol (TCP) levels in blood showed maximum values at 5 h post-injection, and then decreased rapidly. Biological half-lives of the blood chlorpyrifos and TCP were estimated to 8.15 and 24.66 h, respectively. Urine was collected for 96 h post-injection and hydrolyzed with 4 N HCl or beta-glucuronidase with sulfatase, and TCP released was determined. Urinary excretion levels of the acid hydrolysis-released TCP and the enzyme hydrolysis-released TCP accounted for 86 and 54% of chlorpyrifos administered, respectively. Urinary excretion levels of alkylphosphate for 96 h post-injection were analyzed. The excretion levels of diethylthiophosphate (DETP) and diethylphosphate (DEP) accounted for 45 and 15% of chlorpyrifos administered, respectively. These results indicate that 1) about half of the chlorpyrifos administered was directly hydrolyzed to DETP and TCP, 2) 10 to 20% was hydrolyzed to DEP and TCP after the oxidation to chlorpyrifos oxon, and 3) about 30% was dealkylated to TCP-phosphate after the oxidation.
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PMID:[Metabolism and urinary excretion of chlorpyrifos in rats]. 247 31

The enzymes sulfatase and beta-glucuronidase from Helix pomatia were simultaneously immobilized on aminopropyl control pore glass. Once immobilized, these enzymes retained activity under varied conditions of pH, organic solvent, and temperature. To hydrolyze the sulfate and glucuronide conjugates of xenobiotics, the immobilized enzymes were either added directly to incubation mixtures for qualitative in vitro studies or packed in a short stainless steel column and placed in an HPLC system for quantitative studies. By incorporating specific inhibitors (D-saccharic acid-1,4-lactone to inhibit beta-glucuronidase or phosphate ions to inhibit sulfatase) into the incubation mixture or into the HPLC mobile phases, selective hydrolysis of either sulfate or glucuronide conjugates was achieved. Upon removal of the inhibitors from the incubation mixtures or from the mobile phases, original enzyme activity was restored. The utility of immobilized enzymes was demonstrated for quantitative analysis of sulfate and glucuronide conjugates of fenoldopam, where the liberation of the catechol aglycone moiety was necessary for electrochemical detection.
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PMID:Immobilized sulfatase:beta-glucuronidase enzymes for the qualitative and quantitative analysis of drug conjugates. 256 76

Cigarette smokers have been reported to void urine which is more mutagenic, as measured in the Ames bacterial mutation assay, than urine voided by non-smokers. Condensate from the mainstream smoke of a cigarette which heats, but does not burn tobacco (test cigarette) showed no evidence of mutagenicity in a battery of in vitro genotoxicity assays under conditions in which condensate from the mainstream smoke of cigarettes that burn tobacco was mutagenic. The objective of this study was to determine whether the absence of mutagenic activity observed in the in vitro assays would be reflected in the urine of smokers of the test cigarette. 72 subjects (31 smokers and 41 non-smokers) were enrolled in a 6-week study, with the smokers randomly divided into 2 groups. The study was designed as a double crossover, with each smoker smoking both test (tobacco-heating) and reference (tobacco-burning) cigarettes. This design allowed each smoker to serve as his or her own control while at the same time allowing comparisons between groups of non-smokers and smokers of both test and reference cigarettes. 24-h urine samples were collected twice a week and concentrated using XAD-2 resin. Urine concentrates were tested in Ames bacterial strains TA98 and TA100, with and without metabolic activation and with and without beta-glucuronidase/aryl sulfatase. Individuals who smoked the test cigarette voided urine which was significantly less mutagenic than that voided when they smoked reference cigarettes. The mutagenicity of urine from smokers who smoked the test cigarette and non-smokers did not differ under any of the assay conditions used in this study.
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PMID:Human urine mutagenicity study comparing cigarettes which burn or only heat tobacco. 273 80


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