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)

Secondary cultures of hamster embryo cells exposed to 0.5 nmol [G-3H]7,12-dimethylbenz(a)anthracene (DMBA) per ml medium metabolized more than 90% of the DMBA within 48 hr. Samples of medium were extracted with chloroform, methanol, and water. The chloroform phases contained about one-third of the DMBA metabolites; the major chloroform-extractable metabolite was 8,9-dihydro-8,9-dihydroxy-7,12-dimethylbenz(a)anthracene. Beta-glucuronidase treatment of the aqueous methanol-soluble metabolites converted almost one-half of them to chloroform-soluble metabolites, of which more than 80% were identified as phenolic derivatives of DMBA. Similar metabolite profiles were obtained by treating the medium with beta-glucuronidase before chloroform extraction. Separation of the methyl group-hydroxylated derivatives of DMBA from the phenolic derivatives was accomplished by high-pressure liquid chromatography. Small amounts of hydroxymethyl derivatives were detected only in the chloroform-extractable material, whereas DMBA phenols were the major component of the beta-glucuronidase-released mateirla. These results indicate that the major pathway of DMBA metabolism in hamster embryo cells is oxidation of the aromatic rings and not oxidation of the methyl groups.
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PMID:Formation of glucuronic acid conjugates of 7,12-dimethylbenz(a)anthracene phenols in 7,12-dimethylbenz(a)anthracene-treated hamster embryo cell cultures. 9 31

Radiolabeled diethylstilbestrol (DES) was administered to one pregnant and three normal female rhesus monkeys. One normal female chimpanzee was also included in the study. Regardless of the mode of presentation (oral versus intravenous), the urine was the principal route of excretion for each species. The urine contained no non-polar radioactivity, and Sephadex LH-20 (MeOH/EtOH-50:50) resolved the radioactivity into five fractions (A, B, C, D, E). Fractions A,B, C, and D were hydrolyzable with beta-glucuronidase, and the principal aglycones were identified with GC/MS as cis-trans DES and dienestrol. The fecal excretory products were extracted with dimethoxy methane/methanol (50:50) and the radioactivity partitioned between benzene and H2O. The polar radioactivity was resolved by LH-20 (MeOH/EtOH-50:50) into chromatographic fractions similar to the urinary conjugates. These fecal conjugates were, however, less sensitive to beta-glucuronidase hydrolysis. The primary non-polar fecal radioactivity was chromatographically similar to DES (LH-20 and HPLC) in both species, and in the rhesus monkey the principal products identified were cis-trans DES and dienestrol.
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PMID:The metabolism of diethylstilbestrol in the rhesus monkey and chimpanzee. 10 73

Metabolites of 3'-methyl-4-(dimethylamino)azobenzene (3'-Me-DAB) in the rat bile and urine were investigated by the use of a tracer technique. 3H-3'-Me-DAB in cottonseed oil was administered orally by a stomach tube. The dye metabolites in the bile and urine collected during 24 hr after the administration were hydrolyzed with beta-glucuronidase/arylsulfatase. The hydrolyzed metabolites were then extracted with chloroform or separated by chromatography on Amberlite XAD-2 using methanol as a solvent. The metabolites in the chloroform or methanol eluates were identified by the reverse isotope dilution analysis, before or after separation by thin-layer chromatography. The N-demethylated, aryl hydroxylated, and their azo-reduced products were detected in the bile, in addition to the products oxidized at the ring methyl group as the new metabolites. On the other hand, the metabolites retaining the azo-linkage were scarcely detected in urine and instead 3-aminobenzoic acid, 3-amino-6-hydroxytoluene, and their N-acetylated products were major metabolites in urine. These results indicate that the metabolism of 3'-Me-DAB in the rat involves oxidation of the ring methyl group. Significance of the ring methyl group in the carcinogenic action of aminoazo dyes is also discussed.
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PMID:Analysis of biliary and urinary metabolites of 3'-methyl-4-(dimethylamino)azobenzene in rats. 10 70

A radioimmunoassay for the measurement of both unconjugated and conjugaged estetrol in plasma has been developed. The antiserum obtained after 6 months of immunization with 6-oxoestetrol-6-(O-carboxy-methyl)oxim-BSA was used at a final dilution of 1:90,000 and showed almost no cross reaction with other steroids except for estriol at 1.24%. Esterol-glucosiduronate was synthesized by incubating with adrenalectomized rat liver homogenate and uridine diphosphoglucuronic acid. Then, plasma estetrol-glucosiduronate was measured in the same manner for unconjugated estetrol after hydrolysis with beta-glucuronidase. Sephadex LH-20 column chromatography (7X110 mm, benzene:methanol, 85:15) was employed for accurate assessment. The sensitivity was 10 pg and the smallest amount measurable was 40 pg/sample. The method bland was consistently negligible. The intra and inter assay precision was 11.8% and 14.2% for unconjugated estetrol and that for estetrol-glucosiduronate was 13.5% and 17.1%.
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PMID:A radioimmunoassay of plasma unconjugated and conjugated estetrol. 20 82

[14C] Cholesterol-5 alpha, 6 alpha-expoxide, administered to mice by either gastric intubation or skin painting, was rapidly and primarily excreted in the feces. Residual amonts of the epoxide and its metabolites were found in a wide variety of organs, and persisted for at least 72 hr. At some sites (principally the liver, the small intestinal contents and the combined stomach/duodenum and their contents), the labeled compound existed in a water-soluble form which could not be extracted with chloroform/methanol. Treatment of the small intestinal contents with a preparation of beta-glucuronidase/sulfatase produced a marked increase in the amount of organic-solvent-extractable cholesterol-alpha-epoxide and other polar metabolites. Unchanged epoxide was found mainly in the feces and the skin at the site of application. On the basis of these results, stool specimens, and not blood samples, should be analyzed to detect the presence of this compound and/or its metabolites in vivo.
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PMID:The metabolic fate of cholesterol-5 alpha, 6 alpha-expoxide in vivo. 48 Nov 35

A sensitive procedure was developed for 3',4',7-tris[O(beta-hydroxyethyl)]rutoside (I) in urine. The method is based on the fluoresence behavior of the I-aluminum complex in absolute methanol. This complex has activation and emission wavelengths of 420 and 480 nm, respectively. Optimum conditions for the reaction were investigated. The fluorescence was linear (r = 0.998) in the range of 0.1-4.0 microgram of I/ml. At concentrations below 0.1 microgram/ml, a shift in the emission wavelength was observed. Replicate studies (n = 9) of spiked urine samples, each containing 0.4 microgram of I/ml, showed good precision with a relative standard deviation of 0.009. Overall percent recovery (+/- SEM) from five urine samples was 99.5 +/- 1.34%. Following a single 500-mg po dose of I to individuals, only traces of I were found in the urine. However, beta-glucuronidase treatment of urine resulted in a total cumulative urine excretion of 26.53 mg of I after 78.6 hr.
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PMID:Spectrophotofluorometric analysis of 3',4',7-tris[O-(beta-hydroxyethyl)]rutoside in urine. 67 Dec 54

Human polymorphonuclear leukocyte (PMN) elastase has been implicated in various pathological conditions. However, its physiological role remains undefined. One possible function of this enzyme may be digestion of bacterial proteins after phagocytosis. To test this hypothesis, we prepared Escherichia coli labeled with [3H]arginine and treated these bacteria with a lipid-soluble, active-site-directed chloromethyl ketone inactivator of pancreatic and granulocyte elastases (carbobenzoxy-L-glycyl-L-leucyl-L-alanine chloromethyl ketone, dissolved in methanol). Control bacteria were treated with methanol alone. When E. coli pretreated with the inactivator were incubated with solutions of porcine pancreatic elastase or with PMN granule extract, release of trichloroacetic acid-soluble radioactivity was significantly lower than in the control E. coli. Similar results were obtained when treated and control E. coli were fed to viable human PMN. In contrast, release of trichloroacetic acid-soluble radioactivity from E. coli containing [3H]thymidine was not affected by pretreatment of bacteria with elastase inactivator before feeding them to PMN, suggesting that phagocytosis of E. coli had not been inhibited by the chloromethyl ketone. When treated and control bacteria were fed to PMN, no significant difference was observed in the activity of lysosomal beta-glucuronidase recovered from post-granule supernatant fractions of homogenized leukocytes, suggesting that lysosomal degranulation had not been suppressed by the inactivator. However, elastase activity of the same fractions was depressed if the leukocytes had phagocytized chloromethyl ketone-treated E. coli, suggesting that inhibition of PMN elastase had occurred. We conclude that PMN elastase participates in digestion of E. coli proteins by human PMN.
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PMID:The role of lysosomal elastase in the digestion of Escherichia coli proteins by human polymorphonuclear leukocytes: experiments with living leukocytes. 78 11

For the enantiospecific assay of propranolol in biological material, formation of diastereomeric derivatives is one possible approach. The aim of the present study was the development and optimization of three analytical methods based on different chiral reagents: phenylethylisocyanate and the acyl chloride as well as the isocyanate that are derived from the fluorescent S-flunoxaprofen. Pronethalol is used as internal standard in all three procedures and improves the coefficients of variation significantly. After extraction from human plasma or urine, propranolol is reacted with one of these compounds in anhydrous organic solvents with addition of triethylamine. The diastereomeric derivatives are then resolved on an octadecylsilane column using mixtures of water and methanol with or without addition of glacial acetic acid. Good resolutions of the diastereomeric derivatives are found under these conditions. Conjugates are cleaved prior to analysis using beta-glucuronidase-arylsulfatase and assayed as parent propranolol enantiomers. All three procedures were suitable for analysis of propranolol enantiomers in biological samples in the lower nanogram range (1-2 ng/mL). A preliminary clinical study confirmed the known enantiospecificity in the pharmacokinetics of propranolol and showed high concentrations of conjugates with R/S ratios that were similar to those of the parent enantiomers.
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PMID:Improved enantiospecific RP-HPLC assays for propranolol in plasma and urine with pronethalol as internal standard. 168 29

For the enantiospecific assay of propranolol in biological material, formation of diastereomeric derivatives is one possible approach. The aim of the present study was the development and optimization of three analytical methods based on different chiral reagents: phenylethylisocyanate and the acyl chloride as well as the isocyanate that are derived from the fluorescent S-flunoxaprofen. Pronethalol is used as internal standard in all three procedures and improves the coefficients of variation significantly. After extraction from human plasma or urine, propanolol is reacted with one of these compounds in anhydrous organic solvents with addition of triethylamine. The diastereomeric derivatives are then resolved on an octadecylsilane column using mixtures of water and methanol with or without addition of glacial acetic acid. Good resolutions of the diastereomeric derivatives are found under these conditions. Conjugates are cleaved prior to analysis using beta-glucuronidase-arylsulfatase and assayed as parent propranolol enantiomers. All three procedures were suitable for analysis of propranolol enantiomers in biological samples in the lower nanogram range (1-2 ng/mL). A preliminary clinical study confirmed the known enantiospecificity in the pharmacokinetics of propranolol and showed high concentrations of conjugates with R/S ratios that were similar to those of the parent enantiomers.
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PMID:Improved enantiospecific RP-HPLC assays for propranolol in plasma and urine with pronethalol as internal standard. 168 58

A rapid and sensitive method for extracting temazepam from human serum and urine is presented. Free temazepam is extracted from plasma and urine samples using n-butyl chloride with nitrazepam as the internal standard. Temazepam glucuronide is analyzed as free temazepam after incubating extracts with beta-glucuronidase. Separation is achieved using a C8 reversed-phase column with a methanol-water-phosphate buffer mobile phase. An ultraviolet detector operated at 230 nm is used and a linear response is observed from 20 ng/ml to 10 micrograms/ml. The limit of detection is 15.5 ng/ml and the limit of quantitation is 46.5 ng/ml. Coefficients of variation are less than 10% for concentrations greater than 50 ng/ml. Application of the methodology is demonstrated in a pharmacokinetic study using eight healthy male subjects.
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PMID:Determination of temazepam and temazepam glucuronide by reversed-phase high-performance liquid chromatography. 178 47


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