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:2.5.1.18 (glutathione S-transferase)
22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Cytochrome P-450, NADPH-cytochrome c reductase, benzo(a)-pyrene hydroxylase (AHH), 7-ethoxycoumarin-O-deethylase (7-ECOD), epoxide hydrolase (EH), UDP-glucuronyltransferase (UDPGT) and glutathione S-transferase (GSHST) activities in sturgeon (Acipenser baeri) have been measured and partially characterized. 2. Cytochrome P-450-dependent monoxygenase (MO), EH, and conjugation reactions were detected in liver and to a lesser extent in kidney and gills. 3. Hepatic enzyme activities in the sturgeon were equally high or higher than in rainbow trout liver, with the exception of UDPGT whose activity was 14% of that in trout liver. 4. The MO and EH activities displayed the expected pH maxima of 7.5, whereas transferases were relatively independent of the pH in the 6.5-7.5 range. 5. The temperature optima for MO and EH were close to those reported in other fish species, whereas for conjugation reactions the temperature optima were 45 and 60 degrees C for GSHST and UDPGT respectively.
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PMID:Characterization of xenobiotic metabolizing enzymes in sturgeon (Acipenser baeri). 250 31

1. The influence of the dietary flavonoids, chrysin, quercetin, tangeretin, flavone and flavanone, on the components of the rat liver drug-metabolizing enzyme system was examined and compared with two well-known synthetic flavonoids 7,8-benzoflavone and 5,6-benzoflavone. 2. Polyhydroxylated molecules such as quercetin and chrysin, produced no significant changes on phase I and phase II enzyme activities. 3. Flavone was the most potent inducer, and resulted in a mixed type of induction. 7-Ethoxycoumarin O-deethylase (ECOD), 7-ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin depentylase (PROD) activities were increased 2, 30 and 15-fold respectively. p-Nitrophenol UDP-glucuronyltransferase (UDPGT 1), p-hydroxybiphenyl UDP-glucuronyltransferase (UDPGT 2) and glutathione transferase (GST) activities were also induced. 4. Flavanone, which differs from flavone only by the degree of unsaturation of the pyrone ring, produced only a weak increase in monooxygenase activity, but the increase in phase II enzyme activities was as great as that for flavone treatment. 5. Tangeretin displayed a mixed pattern of induction, with increases in ECOD, EROD and PROD, and UDPGT 1 and UDPGT 2 activities, but these were less than with flavone treatment. 6. 7,8-Benzoflavone and 5,6-benzoflavone showed induction patterns similar to those of 3-methylcholanthrene. Nevertheless dietary treatment with 5,6-benzoflavone caused changes which were not as great as those usually described when this compound is administered i.p.
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PMID:Induction of monooxygenase and transferase activities in rat by dietary administration of flavonoids. 251 64

A series of environmentally occurring nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) including those containing nitro-groups oriented coplanarly to the aromatic rings, such as 1- and 3-nitrobenzo[a]pyrene (1- and 3-NBAP), 6-nitrochrysene, and 1- and 4-nitropyrene, and those with a molecular orientation of the nitro-groups perpendicular to the aromatic moieties, such as 7-nitrobenz[a]anthracene and 6-nitrobenzo[a]pyrene (6-NBAP), were used to study the induction of certain rat hepatic phase II conjugating enzymes. Effects of these two different classes of nitro-PAHs on microsomal UDP-glucuronyltransferase (UDPGT), cytosolic glutathione S-transferases (GSTs) and sulfotransferases (STs) were investigated. After three consecutive daily i.p. injections, 1- and 3-NBAP and 6-nitrochrysene significantly increased the activities of UDPGT and GST, whereas their parent PAHs did not induce UDPGT (and GST activity was also unaltered by benzo[a]pyrene). UDPGT and GST activities were also significantly increased by 1-nitropyrene. In contrast, the sulfotransferases directed to 2-naphthol were not significantly induced by any PAH or nitro-PAH when assayed at either pH 5.5 or 7.5; however, the activities of aryl STs III and IV (pH 5.5) were significantly decreased following treatment with pyrene and two nitro-compounds, 6-NBAP and 7-nitrobenz[a]anthracene, in which the nitro-group is oriented perpendicular to the aromatic moiety. These results indicate that a coplanar orientation of the nitro-group of certain nitrated PAHs facilitates the induction of hepatic phase II enzymes by these compounds in rats, and the comparable induction patterns for P450IA1, UDPGT, and GST provide further evidence supporting the coordinate regulation (through the Ah receptor) of these phase I and phase II activities.
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PMID:Effect of nitro-substitution of environmental polycyclic aromatic hydrocarbons on activities of hepatic phase II enzymes in rats. 251 57

Feeding of vitamin A-deficient diet to male weanling rats for 10 weeks caused significant increase in the activities of Phase I enzyme system, i.e., cytochrome P-450, cytochrome b5 and arylhydrocarbon hydroxylase in the proximal, middle and distal segments of the intestine. Of the Phase II enzymes studied, UDP-glucuronyltransferase showed significant decrease whereas glutathione S-transferase showed significant increase. Treatment with benzo(a)pyrene caused greater induction in the levels of Phase I enzymes in deficient animals as compared to controls. In contrast to this, benzo(a)pyrene treatment induced the level of UDP-glucuronyltransferase in control rats more than in deficient rats. Intestinal NADPH cytochrome C-reductase and glutathione S-transferase remained insensitive to benzo(a)pyrene induction.
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PMID:Effects of dietary benzo(a) pyrene on intestinal phase I and phase II drug metabolizing systems in normal and vitamin A-deficient rats. 261 43

There is a varied distribution of airway epithelia throughout the respiratory tract that may explain the apparent differential susceptibility of respiratory tract tissues to carcinogens. The objective of this research was to characterize the distribution of xenobiotic metabolizing enzymes in the respiratory tract of the dog and to determine if regional variances in metabolic capability are associated with morphologic differences of surface epithelium among airways. Specific regions from one-half of the nasal, tracheal, bronchial, and pulmonary airways were excised and analyzed for the presence of xenobiotic metabolizing enzymes. Complementary halves of airways were fixed and processed for light microscopy. Substrates for different isozymes of cytochrome P-450, including benzo(a)pyrene, nitropyrene, ethoxycoumarin, and ethoxyresorufin and select Phase II enzymes were measured. The data for benzo(a)pyrene and nitropyrene were qualitatively similar in that there was high metabolic activity in certain regions of the nasal tissue (e.g. ethmoid turbinates) and in the intrapulmonary airway generations 3-18 compared with the major conducting airways (e.g. larynx, trachea, and bronchi). Most ethoxycoumarin O-deethylase activity was in the nasal region with much less activity observed in the major airways or the pulmonary airways. The specific activity of ethoxycoumarin O-deethylase in the ethmoid turbinates was, in general, 5-10 times that observed for the other portions of the nasal cavity sampled. Only the ethmoid turbinates showed evidence of ethoxyresorufin metabolism. Both epoxide hydrolase and glutathione transferase activity was higher in the various tissues of the nasal cavity and in the pulmonary airways compared with the major conducting airways. UDP-glucuronyltransferase was relatively evenly distributed throughout the respiratory tract.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Regional distribution of xenobiotic metabolizing enzymes in respiratory airways of dogs. 289 39

Previously we established that 'LEC rats' have displayed spontaneous fulminant hepatitis with severe jaundice, which progressed to liver cancer, and a single autosomal recessive gene is responsible for the cause of the diseases. The activities of drug metabolizing enzymes were assayed in livers from LEC and control (LEA) rats at 4 weeks and 3 months before the onset of liver cancer. At 4 weeks the cytochrome P-450 content of the LEC rat livers was 43% of the control (LEA) value. At 3 months the level was 65% of the control. Epoxide hydrolase, gamma-glutamyltranspeptidase and UDP-glucuronyltransferase activities were 2.6-, 6.9- and 2.4-times higher than those in the LEA rats at 4 weeks, respectively, while glutathione S-transferase activity was not significantly different between the two strains. The enzyme changes in the LEC rats are quite similar to those observed in hyperplastic foci and nodules in chemical carcinogenesis of hepatocytes.
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PMID:Metabolic predisposition of a novel mutant (LEC rats) to hereditary hepatitis and hepatoma: alterations of the drug metabolizing enzymes. 290 Jul 2

In a 17 year-old male patient with Rotor's syndrome, hepatic glutathione S-transferase activity toward 1-chloro-2,4-dinitrobenzene reduced to about 0.2% of the mean activity of patients with other diseases. The activities toward sulfobromophthalein and 1,2-dichloro-4-nitrobenzene were low (44% and 47%, respectively, of those controls), but basically present. Bilirubin UDP-glucuronyltransferase activity in this Rotor's syndrome case was in the normal range.
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PMID:Partial defect in hepatic glutathione S-transferase activity in a case of Rotor's syndrome. 295 40

Activities of glucuronosyltransferase, sulfotransferase, glutathione S-transferase, beta-glucuronidase and sulfatase were determined in microdissected samples of periportal and pericentral sublobular regions from four human livers obtained at immediate autopsy. New methods are presented for the microdetermination of sulfotransferase and sulfatase activities in microdissected samples weighing 0.1 to 4 micrograms dry weight using umbelliferone and 4-methylumbelliferone sulfate as substrates. The three transferases were distributed heterogeneously across the liver lobule. Glucuronosyltransferase and glutathione S-transferase were localized predominantly in pericentral regions. In contrast, sulfotransferase activity was greater in periportal than pericentral regions. Average activities for glucuronosyltransferase and sulfotransferase were 23, and 50 mumoles X gm dry wt-1 X hr-1, respectively, in periportal regions, and 34 and 38 mumoles X gm dry st-1 X hr-1, respectively, in pericentral regions. Activities of glutathione S-transferase were considerably higher than those of the other transferases and were 8.3 mmoles X gm dry wt-1 X hr-1 in periportal areas and 12.2 mmoles X gm dry wt-1 hr-1 in pericentral areas. The two hydrolases studied, beta-glucuronidase and sulfatase, were evenly distributed across the liver lobule. The presence of significant hydrolase and transferase activities in both zones of the liver lobule supports the idea that net production of both sulfate and glucuronide conjugates may be influenced by futile cycling of conjugation-deconjugation reactions in both zones of the liver. Based on enhanced formation of sulfate but not glucuronide conjugates in homogenates of human liver treated with inhibitors of the hydrolases, it is suggested that futile cycling is more pertinent to the regulation of sulfation than glucuronidation.
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PMID:Sublobular distribution of transferases and hydrolases associated with glucuronide, sulfate and glutathione conjugation in human liver. 308 5

Male Fisher rats were fed a diet ad lib. containing eugenol (4-allyl-2-methoxyphenol) to observe its effects on liver drug-detoxifying enzymes such as UDP-glucuronyltransferase (GT), UDP-glucose dehydrogenase (DH) and glutathione S-transferase (GST). Liver weights were not affected significantly by a diet containing 3% eugenol (w/w) for 13 weeks. The activities of GT of liver microsomes toward various xenobiotic substances such as 4-nitrophenol, 1-naphthol, 4-hydroxybiphenyl and 4-methylumbelliferone were enhanced by dietary administration of eugenol, but the activity of GT toward its endogenous substrate, bilirubin, was not changed. Dose-response relationships between the enhancement of GT activities toward these xenobiotics and the dose of eugenol were observed. The induced higher activities of GT toward these xenobiotics were maintained during 13 weeks of eugenol treatment. Similar results on DH and GST activities in the liver cytosol were obtained by dietary administration of eugenol, while no effect on cytochrome P-450 content in the liver microsomes from the rats fed the eugenol diet was observed during 13 weeks. These results suggest that the intracellular content of the active intermediates of various drugs or carcinogens would be reduced by this specific enhancement of drug-detoxifying enzymes in the liver of rats given a diet containing eugenol, as previously described for a diet containing 2(3)-tert-butyl-4-hydroxyanisole (BHA) [Y-N. Cha and H. S. Heine, Cancer Res. 42, 2609 (1982)].
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PMID:Enhancement of UDP-glucuronyltransferase, UDP-glucose dehydrogenase, and glutathione S-transferase activities in rat liver by dietary administration of eugenol. 312 37

Changes in the hepatic drug/xenobiotic-metabolizing enzymes in underfed rats exposed to aflatoxin B1 and N-acetylaminofluorene were investigated. Neither carcinogen, fed at the level of 10 micrograms and 0.667 mg per 100 g body weight, respectively, over a period of 3 wk, had any significant influence on cytochrome P-450 and aryl hydrocarbon hydroxylase in the undernourished rats. Significantly low activities of UDP-glucuronyltransferase and glutathione S-transferase were observed in food-restricted animals fed on aflatoxin B1. N-acetylaminofluorene, on the other hand stimulated both the enzyme activities in the underfed group, to as much observed in the respective well-fed treated group. UDP-Glucuronyltransferase and glutathione S-transferase in undernutrition seem to respond differently to aflatoxin B1 and N-acetylaminofluorene. Further studies are needed to assess the possible consequences of such alterations.
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PMID:Differences in response of glucuronide and glutathione conjugating enzymes to aflatoxin B1 and N-acetylaminofluorene in underfed rats. 313 40


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