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

---

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

Water solubility and non-toxic properties of ascorbic acid are taken as criteria for beneficial effects of large doses of the vitamin. In the present study, male guinea pigs, dosed daily with 15, 30 or 50 mg/100g body weight for 10 weeks, demonstrated no differences in effect on liver and lung weights, body growth and microsomal protein contents of liver and lung when compared with controls. When guinea pigs were fed excessive ascorbic acid, there was a small non-significant increase (p less than 0.05) in hepatic and pulmonary cytochrome P-450, and significant increase (p less than 0.05) in hepatic cytochrome b5 which was accompanied with a significant increase in arylhydrocarbon hydroxylase activity in the two organs. Activity of NADPH-dependent cytochrome c-reductase was decreased in liver and remained unaffected in lung and colon. Drug detoxifying enzymes responded in different ways to increased intake of ascorbic acid. Activity of UDP-glucuronyltransferase remained unchanged on feeding excessive ascorbic acid, whereas glutathione S-transferase was decreased significantly in liver and was unaltered in lung and colon. Reduced glutathione was decreased only in the lung. The observed changes in drug activating and detoxifying enzymes appear to be important from drug pharmacokinetics and carcinogenesis point of view.
...
PMID:Effect of large doses of ascorbic acid on the hepatic and extra-hepatic drug-metabolizing enzymes in guinea pig. 380 Oct 39

The inclusion of rats aboard Spacelab 3 (SL-3) allowed analyses of liver lipids, glycogen, hepatic enzymes of cholesterol, glycerolipid and sphingolipid biosynthesis, and other enzyme activities. Glycogen content was markedly elevated in livers from the flight animals compared with controls. Cholesterol was 24% (P less than 0.04) lower in livers from the experimental groups, whereas blood cholesterol was 19% higher (P less than 0.05). The activity of 3-hydroxy-3-methylglutaryl-CoA reductase, the rate-limiting enzyme of steroid biosynthesis, was 80% lower (P less than 0.01). Total phospholipids and sphingolipid levels did not differ significantly. The specific activity of fatty acyl-CoA synthetase, which is responsible for activation of fatty acids, was 37% (P less than 0.05) higher in microsomes from the rats on SL-3; however, since these animals had 25% less microsomal protein (P less than 0.02), there was no difference per gram of liver. The initial enzymes of sphingolipid and glycerolipid biosynthesis were assayed; serine palmitoyltransferase was 40% lower (P less than 0.01), and glycerol 3-phosphate acyltransferase did not differ. Hepatic cytochrome P-450 content decreased by 50% after spaceflight. Enzymes that did not differ significantly between the two groups include cytochrome b5, glutathione S-transferase, tyrosine aminotransferase, aspartate aminotransferase, and cystathionase. These findings suggest that spaceflight alters hepatic metabolism of several classes of compounds.
...
PMID:Hepatic function in rats after spaceflight: effects on lipids, glycogen, and enzymes. 381 60

The results of the present experiment are shown in terms of the transport of protoheme from mitochondria to apocytochrome b5 when fresh rat liver mitochondria, apocytochrome b5, and cytosol were incubated. The heme transfer protein was purified from rat liver cytosol up to approximately 133-140-fold with a 43% yield by the procedure discussed herein, including Sephadex G-75 and CM-cellulose column chromatography. The final preparation showed apparent homogeneity upon polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Its native form was found to be a dimeric protein with a Mr = 45,000 which consists of a subunit with a Mr = 23,000. In the transporting system, the heme transfer depended on the concentration of mitochondria (donor), apocytochrome b5 (acceptor), and purified transfer protein, respectively. Omission of one of these components led to an almost complete loss of the transfer activity. The transport of mitochondrial protoheme was a rapid reaction which showed approximate linearity until 1.5 min and after that it became saturated. When the functional capacity was tested by the NADH-cytochrome c reductase system, the reconstituted cytochrome b5 expressed its complete original catalytic properties, as well as its characteristic absorption spectra for the hemoprotein. Furthermore, the detailed physicochemical and immunological characterization of the transfer protein provided evidence that the protein is identical with soluble glutathione S-transferase, which conjugates glutathione with a variety of electrophilic compounds. At least one of the glutathione S-transferase isozymes observed was identified as GST-C2, which comprises the subunit of Yb'Yb' by the immunoprecipitation reaction using various anti-glutathione S-transferase isozyme antibodies.
...
PMID:Purification and characterization of cytosolic liver protein facilitating heme transport into apocytochrome b5 from mitochondria. Evidence for identifying the heme transfer protein as belonging to a group of glutathione S-transferases. 392 64

The effect of intratracheal administration of fly ash, benzene extracted fly ash residue and benzene extract of fly ash has been studied on the activity of pulmonary mixed function oxidase. Fly ash, its benzene extract and benzene extracted residue significantly increased the levels of cytochrome P-450, cytochrome b5 and the activities of NADPH-cytochrome c reductase, NADH cytochrome b5 reductase, aminopyrine N-demethylase and glutathione S-transferase in a dose dependent manner. Phenobarbital or 3-methylcholanthrene treatment along with administration of fly ash, its benzene extracted residue and benzene extract of fly ash showed a synergistic effect on the activity of mixed function oxidase. The observed effects were due to chemical causes, i.e. organic and inorganic fractions of fly ash and not, due to its particulate nature. This was shown by the administration of glass beads which caused no alteration in the activity of pulmonary mixed function oxidase.
...
PMID:Induction of pulmonary drug metabolizing enzymes by coal fly ash in rats. 404 29

Transfer of mitochondrial protoheme to apocytochrome b5 in vitro was accomplished in a reconstitution system consisting of isolated mitochondria (donor) and apocytochrome b5 (acceptor), which required the existence of cytosol. Properties of formed cytochrome b5 were confirmed by its absorption spectra and the function as NADH-cytochrome c reductase. The content of formed cytochrome b5 was dependent on reaction time and the concentration of mitochondrial protoheme, apocytochrome b5, and cytosolic protein. This heme transfer protein was purified to homogeneity and identified with glutathione S-transferases (GSTs), by their same elution patterns in column chromatographies and the same degree of inhibited activities on the immunotitration study. Double immunodiffusion analysis revealed this protein to be GST-C2 (Yb' Yb'). These observations lead to the conclusion that Yb' subunit of GST located in the cytosol of rat liver stimulates the transfer of mitochondrial protoheme to apocytochrome b5, which indicates that GST has an unrecognized function as yet, involving on the biosynthesis of microsomal cytochrome b5.
...
PMID:[Isolation and characterization of heme transfer protein involved in biosynthesis of microsomal cytochrome b5 from rat liver cytosol]. 407 16

The effect of pretreatment with o-, m- and p-toluidine on the drug-metabolizing enzymes of liver, kidney and lung in rats were investigated. The activities of microsomal aryl hydrocarbon hydroxylase (AHH), aminopyrine demethylase, NADPH-cytochrome c reductase, epoxide hydrolase, cytosolic glutathione S-transferase as well as the concentrations of cytochrome P-450 and cytochrome b5 were determined. The obtained results showed that o-toluidine increased the activity of AHH in all tested organs; a particularly marked increase was observed in the kidney. The activity of NADPH-cytochrome c reductase and the content of cytochrome b5 were enhanced by o-toluidine only in the liver. m-Toluidine enhanced the glutathione S-transferase activity while the p-isomer increased both the epoxide hydrolase and the glutathione S-transferase activities. p-Toluidine decreased the AHH and aminopyrine demethylase activities and the cytochrome P-450 content. These results may explain in part the previously reported observations on carcinogenic activity of o-toluidine.
...
PMID:Effect of toluidines on drug metabolizing enzymes in rat liver, kidney and lung. 643 87

1. Carbon tetrachloride (0.2 ml/kg) and L-4-oxalysine (200 mg/kg per day for two days) were administered to male mice separately, and together, and the liver drug-metabolizing parameters measured. 2. Carbon tetrachloride alone depleted hepatic microsomal protein content by 50% and cytosolic sulphydryl compounds by 90%; oxalysine alone had no effect. 3. Microsomal cytochrome P-450 was decreased by 60%, cytochrome b5 by 30%, ethylmorphine N-demethylation by 50% and 7-ethyoxycoumarin O-deethylation by 80% following carbon tetrachloride administration; oxalysine had no effect on these losses. 4. After administration of carbon tetrachloride, cytosolic glutathione S-transferase activity was decreased by 16%; this effect was not seen when oxalysine and carbon tetrachloride were given together. Oxalysine alone slightly increased this enzyme activity.
...
PMID:The influence of L-4-oxalysine on carbon tetrachloride-induced changes in drug-metabolizing enzyme activity of mouse liver. 681 4

Changes in hepatic drug-metabolizing enzymes after intraperitoneal treatment of rats with 2-acetylaminofluorene have been investigated. This treatment was found to increase microsomal epoxide hydrolase to 762%, cytochrome P-450 to 143%, NADPH-cytochrome c reductase to 160%, cytochrome b5 to 171%, cytoplasmic DT-diaphorase to 229% and soluble glutathione S-transferase activities to 200-250% of control values. These increases were time- and dose-dependent, being maximal after injection of 50 mg 2-acetylaminofluorene/kg body wt. once daily for 5 days. Enzyme markers for the plasma membrane, mitochondria, lysosomes and the soluble cytoplasm were not affected by treatment with 2-acetylaminofluorene. The present study indicates that this induction is different from that obtained with phenobarbital and 3-methylcholanthrene and more closely resembles that seen with trans-stilbene oxide.
...
PMID:Characterization of the induction of drug-metabolizing enzymes by 2-acetylaminofluorene. 722 16

The modulation caused by arecanut, a major ingredient of the masticatory substance betel quid, on biotransformation system enzymes, acid soluble sulfhydryl (-SH) content and lipid peroxidation was assessed in lactating mice and their neonates. Following parturition, dams were fed a 1% arecanut diet and F1 mice were nursed by their own mothers during the lactation period of 21 days. Arecanut induced significant increases in the levels of cytochrome b5, cytochrome P-450, glutathione S-transferase and malondialdehyde (MDA) in dams and their pups. However, it decreased the -SH content in lactating mice and F1 progeny; whether the F1 mice were exposed to the translactational dose of arecanut for 21 days or to a similar translactational dose plus a dietary dose of arecanut for additional post weaning period of 21 days, the pattern of changes in the profile of biotransformation system enzymes was essentially similar. The changes elicited by arecanut intake in the levels/activities of enzymes of the biotransformation system, MDA level and -SH content may enhance the susceptibility of neonatal stages of mice to the action of chemical carcinogens.
...
PMID:Effect of arecanut, a masticatory, on hepatic drug metabolizing enzymes -SH content and lipid peroxidation in lactating mothers and their suckling neonates. 760 May 28

It has been shown previously that the anticonvulsant agent, sodium valproate, induces certain cytochrome P-450 monooxygenase activities and decreases glutathione S-transferase activity. We have used Western blotting, RNase protection assays and Northern blot hybridization to determine the effects of valproate on the abundance of individual components of the cytochrome P-450 monooxygenase and of glutathione S-transferase subunits. Due to the short half-life of the drug in rats we have used an in vitro experimental system comprised of rat hepatocytes co-cultured with rat primitive biliary epithelial cells. Valproate was shown to be a potent inducer of two members of the cytochrome P-450 (CYP)2B subfamily, CYP2B1 and 2B2. The induction of the proteins was mediated at the level of the mRNAs, with the mRNA for CYP2B1 being more highly induced than that for CYP2B2. The drug also induced, but to a much lesser extent, two important components of the cytochrome-P-450-mediated monooxygenase system, NADPH-dependent cytochrome P-450 reductase and cytochrome b5, and their corresponding mRNAs. Thus, the effects of valproate on cytochromes P-450 and other components of the cytochrome-P450-mediated monooxygenase system mimic those of another, structurally diverse, antiepileptic drug, phenobarbital. However, in contrast to phenobarbital, which induces glutathione S-transferase subunits 1, 2, 3, 4 and 7, valproate selectively decreases the abundance of subunits 3 and/or 4. It has been shown previously that CYP2B1 is involved in the production of metabolites of valproate implicated in hepatotoxicity. The induction of this protein by valproate would thus contribute substantially to the hepatotoxic effects associated with the drug.
...
PMID:Effects of the anticonvulsant, valproate, on the expression of components of the cytochrome-P-450-mediated monooxygenase system and glutathione S-transferases. 763 45


<< Previous 1 2 3 4 5 6 7 8 9 Next >>

---