Gene/Protein
Disease
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Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
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Target Concepts:
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Query: EC:1.6.5.2 (
NQO1
)
6,196
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Male mice were exposed via their diet to perfluoro fatty acids of various chain-lengths (2-10 carbon atoms) at different doses (0.02 and 0.1% weight) and for different periods of time (2-10 days). Thereafter, we monitored effects on liver and body weights and a number of hepatic parameters, including mitochondrial protein content, microsomal contents of cytochromes P450 and b5, NADPH-cytochrome P450 reductase activity [measured as NADPH-cytochrome c reductase (EC 1.6.2.3)], microsomal and
cytosolic epoxide hydrolase
(EC 3.3.2.3) activities, cytosolic
DT-diaphorase
(EC 1.6.99.2), glutathione transferase (EC 2.5.1.18), glutathione peroxidase (EC 1.11.1.9) and superoxide dismutase (EC 1.15.1.1) activities, and levels of thiobarbituric acid-reactive material (as an indicator of lipid peroxidation) in the mitochondrial subfraction. The most dramatic changes observed were a 5-9-fold increase in mitochondrial protein, a 3-6-fold increase in the microsomal content of cytochrome P450, a 3-10-fold increase in cytosolic
DT-diaphorase
activity, an approximately 2-fold increase in
cytosolic epoxide hydrolase
activity and as much as a 60% decrease in the level of thiobarbituric acid-reactive compounds in the mitochondrial fraction. Smaller increases in microsomal epoxide hydrolase activity and decreases in cytosolic glutathione peroxidase activity were also observed. Of the perfluoro fatty acids tested, perfluorooctanoic acid caused the largest changes in the parameters examined here. Dietary exposure of mice to a 0.02% dose of this substance for 10 days results in a maximal or near-maximal effect in most cases.
...
PMID:Effects of perfluoro fatty acids on xenobiotic-metabolizing enzymes, enzymes which detoxify reactive forms of oxygen and lipid peroxidation in mouse liver. 141 40
Male and female C57Bl/6 mice were administered perfluor-octanoic acid PFOA; 0.02-0.05% w/w; 5-10 days) in their diet. This treatment resulted in a several-fold induction of hepatic peroxisomal fatty acid beta-oxidation (monitored as increases in cyanide-insensitive palmitoyl-CoA oxidation, lauroyl-CoA oxidase and catalase activity) in all animals. The protein content of the hepatic mitochondrial fraction was also increased in all mice exposed to PFOA. Furthermore, studies on xenobiotic-metabolizing enzymes revealed no sex-related difference in the response to PFOA. All mice demonstrated a dramatic increase in omega-hydroxylation of lauric acid.
Cytosolic epoxide hydrolase
, glutathione transferase and
DT-diaphorase
activities were increased about 2-5-fold. These results with mice differ dramatically from previous studies and our own experiments here with Wistar rats, in which exposure to PFOA causes hepatic peroxisome proliferation in male animals, whereas females are unaffected.
...
PMID:The effects of perfluoro-octanoic acid on hepatic peroxisome proliferation and related parameters show no sex-related differences in mice. 149 16
This study was performed in order to study the response of epoxide hydrolases in different subcellular compartments of mouse liver to treatment with various compounds. Male C57BL/6 mice were treated with 31 different compounds--including traditional inducers of xenobiotic-metabolizing systems, liver carcinogens, stilbene derivatives, endogenous compounds and various other drugs and xenobiotics. The effects on liver somatic index; protein contents in 'mitochondria', microsomes and cytosol prepared from the liver; epoxide hydrolase activity towards trans- or cis-stilbene oxide in these three fractions; microsomal cytochrome P-450 content; cytosolic and 'mitochondrial' glutathione transferase activity and cytosolic
DT-diaphorase
activity were then determined.
Cytosolic epoxide hydrolase
activity was induced by chlorinated paraffins, di(2-ethylhexyl)phthalate and clofibrate and depressed by alpha-naphthylisothiocyanate, 3-methylcholanthrene, benzil and quercitin. Radial immunodiffusion revealed similar changes in the amount of enzyme protein present, except for two cases, where the increase in amount was larger; and the enzyme seems to be inhibited by benzil. Microsomal epoxide hydrolase activity was induced by these same compounds and several others as well, including dibenzoylmethane, butylated hydroxyanisole and polychlorinated biphenyls. 'Mitochondrial' epoxide hydrolase activity towards trans-stilbene oxide was not affected by those compounds which induced the cytosolic enzyme, but increased about two-fold after treatment with 2-acetylaminofluorene, DL-ethionine, aflatoxin B1 and phenobarbital. There does not seem to be any co-regulation of different forms of epoxide hydrolase in mouse liver. In general small effects were observed on liver weight and protein contents in the different subcellular fractions. Polychlorinated biphenyls were the most potent of the 8 compounds which induced cytochrome P-450, while butylated hydroxyanisole induced cytosolic glutathione transferase activity to the highest extent. 'Mitochondrial' glutathione transferase activity was most induced by certain of the stilbene derivatives. The most potent inducers of
DT-diaphorase
activity were 3-methylcholanthrene, polychlorinated biphenyls and dinitrotoluene.
...
PMID:Hepatic levels of cytosolic, microsomal and 'mitochondrial' epoxide hydrolases and other drug-metabolizing enzymes after treatment of mice with various xenobiotics and endogenous compounds. 362 71
Biochemical and histochemical studies were conducted in aflatoxin B1-induced liver tumors in adult rainbow trout. Specific activities of the phase I enzymes, ethoxyresorufin-O-deethylase (EROD), microsomal and
cytosolic epoxide hydrolase
(mEH and cEH), aldehyde dehydrogenase (ALDH) and
DT-diaphorase
, and the phase II enzymes, gamma-glutamyltransferase (gamma-GT), glutathione transferase (GST) and uridine diphosphoglucuronyl transferase (UDPGT) were measured. Cryostat sections of tumor and surrounding liver from the same cohorts were analyzed immunohistochemically for cytochrome P450IA1 and histochemically for ALDH (benzaldehyde and hexanal),
DT-diaphorase
, gamma-GT and uridine diphosphoglucuronyl dehydrogenase (UDPGdH). In tumor tissues, the largest biochemical changes were found with benzaldehyde dehydrogenase, where activity increased from undetectable levels to 7.4 nmol/min/mg protein, and gamma-GT, where activity increased 12-fold over controls. Increases in other enzymes ranged from 1.26 to 2.84 times that of control liver, except EROD, which decreased, and cEH and mEH, which were unchanged. Histochemical analyses showed the induction of ALDH, gamma-GT,
DT-diaphorase
and UDPGdH, and the depression of cytochrome P450IA1 in hepatic neoplasms. In addition, marker enzyme histochemistry of neoplasms revealed heterogeneous populations of hepatocytes and absence of necrotic areas.
...
PMID:Biochemical and histochemical properties of hepatic tumors of rainbow trout, Oncorhynchus mykiss. 809 46
Perfluorooctane sulfonic acid is almost as potent as perfluorooctanoic acid in causing increases in peroxisomal fatty acid beta-oxidation, peroxisomal catalase activity, omega-hydroxylation of lauric acid,
cytosolic epoxide hydrolase
activity and cytosolic
DT-diaphorase
activity. Octane sulfonic acid was ineffective at doses used for perfluorooctane sulfonic acid and perfluorooctanoic acid. The results support the theory of co-regulation of these parameters and peroxisome proliferation. The fact that perfluorooctane sulfonic acid causes peroxisome proliferation challenges the hypothesis that the first step in this process is formation of a thioester between the proliferator (the carboxylic group) and coenzyme A.
...
PMID:Perfluorooctane sulfonic acid is a potent inducer of peroxisomal fatty acid beta-oxidation and other activities known to be affected by peroxisome proliferators in mouse liver. 838 58
Knowledge of genetic polymorphisms in gene-environment studies may contribute to more accurate identification of avoidable risks and to developing tailor-made preventative measures. The aim of this study was to describe the allele frequencies of single nucleotide polymorphisms (SNPs) of select genes, which may be included in future gene-environment studies on cancer in Japan. SNP typing was performed on middle-aged Japanese men randomly selected from the general population in five areas of Japan. We genotyped and calculated allele frequencies of 153 SNPs located on 40 genes: CYP1A1, CYP1B1, CYP2C9, CYP2C19, CYP2E1, CYP17A1, CYP19A1, AHR, ESR1, ESR2, ERRRG, PGR, EPHX1,
EPHX2
, HSD17B2, HSD17B3, GSTM2, GSTM3, GSTT2, GSTP1, NAT1, NAT2, COMT, ADH1A, ADH1B, ADH1C, ALDH2, NOS2A, NOS3, IL1A, IL1B, OGG1, NUDT1 [MTH1], DRD2, DRD3, DRD4, SLC6A4, NR3C1 [GCCR], MTHFR, and
NQO1
. In the present study, the Japanese allele frequencies were verified by using nationwide population samples.
...
PMID:Allele frequencies of single nucleotide polymorphisms (SNPs) in 40 candidate genes for gene-environment studies on cancer: data from population-based Japanese random samples. 1463 38
Aromatic amines (AAs) and polycyclic aromatic hydrocarbons (PAHs) are carcinogens present in tobacco smoke and functional polymorphisms in NAT2 and GSTM1 metabolizing genes are associated with increased bladder cancer risk. We evaluated whether genetic variation in other candidate metabolizing genes are also associated with risk. Candidates included genes that control the transcription of metabolizing genes [aryl hydrocarbon receptor (AHR), AHRR and aryl hydrocarbon nuclear translocator (ARNT)] and genes that activate/detoxify AA or PAH (AKR1C3, CYP1A1, CYP1A2, CYP1B1, CYP3A4, EPHX1,
EPHX2
,
NQO1
, MPO, UGT1A4, SULT1A1 and SULT1A2). Using genotype data from 1150 cases of urothelial carcinomas and 1149 controls from the Spanish Bladder Cancer Study, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) adjusting for age, gender, region and smoking status. Based on a test for trend, we observed 10 non-redundant single-nucleotide polymorphisms (SNPs) in five genes (AKR1C3, ARNT, CYP1A1, CYP1B1 and SULT1A2) significantly associated with bladder cancer risk. We observed an inverse association with risk for the AKR1C3 promoter SNP rs1937845 [OR (95% CI) for heterozygote and homozygote variant compared with common homozygote genotype were 0.86 (0.70-1.06) and 0.74 (0.57-0.96), respectively; P for trend = 0.02]. Interestingly, genetic variation in this region has been associated with lung, non-Hodgkin lymphoma and prostate cancer risk. Analysis of additional SNPs to capture most (approximately 90%) of common genetic variation in AKR1C3 and haplotype walking analyses based on all AKR1C3 SNPs (n = 25) suggest two separate regions associated with bladder cancer risk. These results indicate that genetic variation in carcinogen-metabolizing genes, particularly AKR1C3, could be associated with bladder cancer risk.
...
PMID:Bladder cancer risk and genetic variation in AKR1C3 and other metabolizing genes. 1863 53
It is widely accepted that the cytotoxicity and genotoxicity of benzene results from the action of reactive metabolites. Therefore, genetic variation in metabolic enzyme genes may contribute to susceptibility to chronic benzene poisoning (CBP) in the exposed population. Using a case-control study that included 268 benzene-poisoned patients and 268 workers occupationally exposed to benzene in South China, we aimed to investigate the association between single-nucleotide polymorphisms in genes with phase I and II of metabolism and risk of CBP. The TaqMan technique was used to detect polymorphisms of CYP1A1, CYP1A2, CYP1B1, ADH1B, EPHX1,
EPHX2
,
NQO1
, MPO, GSTP1 and UGT1A6 genes. We also explored potential interactions of these polymorphisms with lifestyle factors such as cigarette smoking and alcohol consumption. A weak positive association was found between glutathione S-transferase pi-1 (GSTP1) rs1695 polymorphism and the risk of CBP (P = 0.046), but this association was not statistically significant (P = 0.117) after adjustment for potential confounders. Further analysis showed that the risk of CBP increased in the subjects with EPHX1 GGAC/GAGT diplotype (P = 0.00057) or AGAC/GAGT diplotype (P = 0.00086). In addition, we found that alcohol drinkers with the EPHX1 rs3738047 GA + AA genotypes and non-alcohol drinkers with the GSTP1 rs1695 AA genotype tended to be more susceptible to benzene toxicity. Our results suggest that genetic polymorphisms in EPHX1 may contribute to risk of CBP in a Chinese occupational population.
...
PMID:Polymorphisms in phase I and phase II metabolism genes and risk of chronic benzene poisoning in a Chinese occupational population. 1878 59