Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

A fibre-free diet, or the same diet supplemented with 100 g cabbage or carrot cell-wall preparation/kg, was fed to rats for 28 days and the activities of a number of caecal microbial enzymes (azoreductase, aryl nitroreductase, beta-glucosidase, beta-glucuronidase, imidazole nitroreductase and nitrite reductase) were determined in vitro. The plant cell-wall preparations diluted the gut contents and decreased the number of bacteria per gram of caecal contents. Enzyme activities per gram of caecal contents were also decreased, with the exception of beta-glucosidase activity which was significantly increased. These plant cell-wall preparations also increased caecal size, and thereby significantly increased total activity per caecum of microbial azoreductase, aryl nitroreductase, beta-glucosidase and beta-glucuronidase. When bacterial metabolism was expressed per 10(9) bacteria, all enzyme activities were significantly increased in caecal samples from rats fed the plant cell-wall preparations. There was an overall concordance of 0.91 between all the enzymes when expressed per 10(9) bacteria, but of only 0.38 when enzyme activities were expressed per gram of caecal contents.
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PMID:Metabolic profile of caecal micro-organisms from rats fed indigestible plant cell-wall components. 629 83

(1) Sensitive fluorimetric assays were developed for the determination of microsomal UDP-glucuronosyltransferase activities towards 1- and 2-naphthylamine and 4-aminobiphenyl. (2) In rat liver microsomes, enzyme activity towards 1-naphthylamine was orders of magnitude higher than the activities towards 2-naphthylamine, 4-aminobiphenyl or aniline. The differences were less marked with human liver microsomes. (3) Glucuronidation of aniline and 4-aminobiphenyl was not appreciably altered in rat liver microsomes from 3-methylcholanthrene- or phenobarbital-treated rats. UDP-glucuronosyltransferase activities towards 1- and 2-naphthylamine were selectively increased (about 2-fold) by 3-methylcholanthrene-treatment. However the increases were less marked than those observed with representative substrates of the 3-methylcholanthrene-inducible enzyme form. The results suggest that the arylamines investigated are predominantly conjugated by constitutive enzyme forms in rat liver. (4) Arylamine N-glucuronides were found to be susceptible to hydrolysis by E. coli beta-glucuronidase suggesting the release of carcinogenic arylamines in the gut and their enterohepatic circulation.
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PMID:N-glucuronide formation of carcinogenic aromatic amines in rat and human liver microsomes. 643 Feb 97

The metabolism of 14C-loprazolam has been studied in rat, dog and man in vivo. In rat, the major metabolic pathways were hydroxylation on the benzodiazepine ring, and reduction and acetylation of the nitro group. Both metabolites were identified by co-chromatography with standards, and were present in urine and bile conjugated with glucuronic acid. In both dog and human urine and bile significant amounts of the piperazine-N-oxide were found. This N-oxide was identified by co-chromatography with authentic compound and by mass spectroscopy. Both loprazolam and the dog biliary metabolites were hydrolysed spontaneously to polar material. Neither treatment with beta-glucuronidase nor incubation with gut microflora had any further effect. Only polar metabolites were found in dog and human faeces. The principal non-polar material found in rat plasma was the diazepine-hydroxy compound, and little loprazolam was present. Significant levels of loprazolam and lower levels of an unidentified metabolite were found in ether extracts of dog and human plasma. Both the piperazine-N-oxide and loprazolam were found in similar quantities in chloroform extracts of human plasma, and at two hours after dosage, the N-oxide and loprazolam accounted for greater than 90% of the radioactivity present in the plasma.
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PMID:Metabolism of loprazolam in rat, dog and man in vivo. 665 50

The excretion and metabolism of 14C-warfarin in rats was examined in a crossover experiment, the first phase consisting of treatment with normal saline, the second phase using the same animals given neomycin, bacitracin, and tetracycline orally. Urine and feces were collected every 24 hours for 72 hours and examined for warfarin and its metabolites, both unconjugated and conjugated. Significantly more radioactivity was eliminated in th feces of antibiotic-treated rats. The feces of antibiotic-treated rats contained only trace amounts of beta-glucuronidase activity. Urine contained a similar ratio of unconjugated to conjugated radioactivity in both treatment groups, but the antibiotic-treated animals had significantly larger amount of conjugates in their feces. Examination of metabolic profiles of conjugated and unconjugated fractions revealed significantly fewer hydroxylated metabolites in antibiotic-treated rats, especially in the feces. The lower amount of hydroxylative metabolism in attributed to a reduction in gut flora-medicated interohepatic recycling caused by the antibiotics.
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PMID:The effect of broad-spectrum antibiotics on warfarin excretion and metabolism in the rat. 732 46

14C-0-[3-(4- less than 2-methoxyphenyl greater than -1-piperazinyl)-2-hydroxypropyl]-3-methoxybenzaldoxim dihydrochloride (HWA 923) was well absorbed (approximately 80%) in rat and dog. In normal animals 37-48% of the radioactivity from a 2 mg/kg of body weight oral or parenteral dose was excreted in the urine, and 48-50% in the faeces. When 14C-HWA 923 was given orally to rats with biliary cannulae, only approximately 10% of the dose was excreted in the urine and approximately 68% appeared in the bile. If bile, collected from animals given 14C-HWA 923, was re-infused intraduodenally into surgically prepared rats, approximately 12% was re-excreted in the urine, and approximately 55% re-excreted in the bile. There were considerably higher levels of radioactivity present in rat blood following intravenous administration of 14C-HWA 923 than after an oral dose, suggesting that radioactivity given via the oral route might be excreted directly into the bile without reaching the systemic circulation. In dog, a significant "first-pass" effect was seen for HWA 923. In a surgically prepared dog, where the bile collection was intermittent, 32% of the dose was excreted in the urine and 46% in the bile. An estimated 73% of the dose would have been present in bile, if continuous collection had taken place. In rat, the major urinary metabolite (up to 40% of the urinary radioactivity) was identified, after specific hydrolysis with beta-glucuronidase, as a demethylated product of HWA 923 by co-chromatography in four solvent systems. This metabolite was present, in rat bile as the conjugates (approximately 40% of the biliary radioactivity), together with significant quantities (approximately 20%) of conjugated HWA 923. The two products were also found on hydrolysis o bile, using gut microflora. Similar results were obtained from dog samples. It is postulated that hydrolysis of the glucuronides of unchanged HWA 923 and its demethylated metabolite by gut micro-flora results in enterohepatic circulation of these two compounds in rat and dog.
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PMID:Enterohepatic circulation in rat and dog of 14C-0-[3-(4-less than 2-methoxyphenyl greater than-1-piperazinyl)-2-hydroxypropyl]-3-methoxy-benzaldoxim dihydrochloride and it's demethylated metabolite. 733 31

7-Ethyl-10-[4-(piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11), a potent anticancer agent for lung and gynecological cancers, is metabolized in vivo to the active compound, 7-ethyl-10-hydroxycamptothecin (SN-38), which is subsequently conjugated to SN-38-glucuronide by UDP-glucuronosyltransferase (UDP-GT). Three purified aglycons of natural glucuronides, baicalein, luteolin and glycyrrhetic acid, inhibited UDP-GT activity towards SN-38 as a substrate. The inhibitory potencies of these aglycons toward UDP-GT were similar to that of 1-naphthol. Based on these results, together with our previous finding that the corresponding glucuronides used in the present study strongly inhibited beta-glucuronidase in gut flora, we propose that materials in Kampo (Japanese herbal) medicines containing these aglycons of natural glucuronides could be used in vivo to decrease the enterohepatic circulation of SN-38 and other drugs.
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PMID:Inhibition of UDP-glucuronosyltransferase by aglycons of natural glucuronides in kampo medicines using SN-38 as a substrate. 749 19

Millions of people die every year in the tropical world from diseases transmitted by hematophagous insects. Failure of conventional containment measures emphasizes the need for additional approaches, such as transformation of vector insects with genes that restrict vectorial capacity. The availability of an efficient promoter to drive foreign genes in transgenic insects is a necessary tool to test the feasibility of such approach. Here we characterize the putative promoter region of a black fly midgut carboxypeptidase gene and show that these sequences correctly direct the expression of a beta-glucuronidase reporter in Drosophila melanogaster. By histochemical staining and mRNA analysis, we found that the gene is expressed strongly and gut-specifically in the transgenic Drosophila. This gut-specific black fly carboxypeptidase promoter provides a valuable tool for the study of disease vectors.
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PMID:Gut-specific transcriptional regulatory elements of the carboxypeptidase gene are conserved between black flies and Drosophila. 756 24

Rhodamine-phalloidin was used to label F-actin in unfixed cells of 13 species of filamentous and blade-forming red algae from the three families Ceramiaceae, Acrochaetiaceae and Bangiaceae. Labelling was achieved only after treatment with either beta-glucuronidase or a combination of cellulase and an extract of snail gut enzyme. Different species required different enzyme treatments and incubation times for successful labelling. All species examined showed extensive arrays of F-actin which generally are confined to the peripheral cytoplasm and are oriented longitudinally. Transverse arrays are present beside the crosswalls of Griffithsia pacifica, and Audouinella species show actin concentrations at the tips of apical cells and in developing branch initials.
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PMID:Rhodamine-phalloidin staining of F-actin in rhodophyta. 768 65

The succession of gut bacteria and selected intestinal enzyme activities in developing 7-35-d-old rats was studied. Aerobes and anaerobes were identified as members of four broad major bacterial groups, i.e. Gram-positive rods, Gram-positive cocci, Gram-negative rods and obligate anaerobes. The enzyme activities of nitro and azo reductases, beta-glucuronidase, dechlorinase and dehydrochlorinase were determined by anaerobic incubation of intestinal homogenates with 3,4-dichloronitrobenzene, methyl orange, p-nitrophenyl-beta-D-glucuronide, and p,p'-DDT respectively. Nitroreductase and azo reductase activities increased significantly with the appearance of anaerobes in the large intestine. No increase in either nitroreductase or azo reductase activities in the small intestine was found. The early and high level of beta-glucuronidase activity in the small and large intestines coincided with high numbers of coliforms recovered in 7 and 14 d animals. Dehydrochlorinase activity appeared early but was undetectable at both 21 and 28 d. Its activity increased at 35 d. Dechlorinase activity was variable in development. The rapid changes in the microbial flora and intestinal enzyme activities may influence the susceptibility of pre-pubescent rats to a variety of toxicants. Therefore, age-dependent toxicity may be important in the risk assessment of some environmental chemicals.
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PMID:Microbial succession and intestinal enzyme activities in the developing rat. 782 31

The effect of giving yogurt supplements to BALB/c mice on the various gut-associated lymphoid cells was studied. Animals were fed for 2, 5, 7 and 10 consecutive days. The different lymphoid cell types were identified and counted by haematoxylin-eosin staining of histological slices. The numbers of cells secreting IgA, IgG and IgM and the numbers of T lymphocytes were determined by direct immunofluorescence. The degree of activation of the intestinal macrophages in the small intestine was assessed by measuring the beta-glucuronidase (EC 3.2.1.31) released into the intestinal fluid, and also by a histochemical method. Throughout the feeding period, there were no histological alterations in the gut, but there was marked cell infiltration, mainly of plasma cells and lymphocytes. The number of macrophages on the small intestine increased significantly after feeding for 2 d, while the beta-glucuronidase activity was only slightly higher that of the controls. After a 7 d feeding period, the number of IgA secreting cells increased, while the values for cells secreting IgM and IgG and for T lymphocytes remained similar to those of the controls. The effect of giving yogurt on lymphoid cells associated with the large intestine was mainly on the numbers of IgA secreting B cells and T lymphocytes, with a marked increase during the whole feeding period in the latter type of cell. Since giving yogurt mainly enhanced the IgA secreting B cells in both small and large intestines, this increase would strengthen the host's defence mechanisms in the intestinal mucosa. Although the number of macrophages was increased, there was no enhancement in their activity, which might have harmed the host by producing an inflammatory response.
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PMID:Effect of yogurt feeding on the small and large intestine associated lymphoid cells in mice. 782 58


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