Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A combined effect of cholesterol and polychlorinated biphenyls (PCBs) on the microsomal drug hydroxylation and glucuronidation in the liver of the rat was studied. PCBs, Clophen A-50 and A-60, having an average chlorination degree of 50 and 60% affect the structure of microsomal membranes. It was found that Clophen A-60 increased the binding of trypsin- and digitonin-sensitive proteins to the membranes. Also it was found that PCBs enhanced the phsopholipid content of microsomes. PCBs increased the activity of hepatic NADPH cytochrome c reductase about 1.5-fold. Aryl hydrocarbon hydroxylase activity doubled with Clophen A-50 and quadrupled with Clophen A-60. Hepatic UDPglucuronosyltransferase activity was doubled with both PCBs. The enhancement in hepatic aryl hydrocarbon hydroxylase and in UDPglucuronosyltransferase was found to be lower in the presence of high cholesterol level in the diet when compared to earlier results. This is supposed to be due to the membraneous effects of cholesterol.
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PMID:Enhancement of hepatic drug biotransformation rate by polychlorinated biphenyls in rats fed cholesterol-rich diet. 81 Sep 23

Investigation of the effect of chlorpromazine hydrochloride (CPZ) on some enzymes involved in the metabolism of the carcinogens 4-dimethylaminoazobenzene (DAB), benzo[a]pyrene, and dimethylnitrosamine (DMN) revealed that CPZ inhibited hepatic microsomal DAB reductase, aryl hydrocarbon hydroxylase, and DMN demethylase II but markedly activated DMN demethylase I. Inhibition of these enzymes in vitro was proportional to the concentrations of CPZ. The effect of CPZ on DMN demethylase also depended on the concentrations of DMN and CPZ in the incubation mixture. Mechanisms to account for the inhibition of DAB reductase were suggested. Aryl hydrocarbon hydroxylase and DMN demethylase II activities of the 100,000 x g hepatic microsomal fraction were activated by 33 and 61%, respectively, over the control values after a single injection of CPZ into F344 rats, but no effect on DAB reductase and DMN demethylase I activities was observed. Microsomal concentrations of protein and cytochrome P450 were not appreciably altered by CPZ treatment, whereas the level of microsomal NADPH cytochrome c reductase was slightly increased over control values. A similar effect on the drug-metabolizing enzymes was found during pretreatment of rats with CPZ for 5 days, except that the NADPH cytochrome c reductase was increased by 33% over the control values.
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PMID:Effect of chlorpromazine hydrochloride on carcinogen-metabolizing enzymes: liver microsomal dimethylnitrosamine demethylase, 4-dimethylaminoazobenzene reductase, and aryl hydrocarbon hydroxylase. 676 70

Aryl hydrocarbon hydroxylase (AHH) activity, NADH-dependent cytochrome c reductase (cyt c) activity, and [3H]thymidine (3H-TdR) incorporation were monitored in human lymphocytes cryopreserved for periods up to 1 year. A standard procedure for freezing, thawing and culturing of these lymphocytes was developed. Kinetics for expression of benz[a]anthracene-(BA)-induced AHH activity, cyt c activity, and 3H-TdR incorporation were similar in both freshly cultured and cryopreserved cells. Lymphocyte samples from 10 individuals were collected once per month over a 3-month period and cells were either cultured at the time of donation or cryopreserved for later assay. Results indicated that the cryopreserved lymphocytes efficiently responded to mitogen activation. The intra-individual variation in AHH activities was reduced in the cryopreserved lymphocytes compared to the freshly cultured cells, and the relative ranking of these individuals in terms of their AHH activities remained constant for both fresh and cryopreserved samples. Cryopreservation seems to offer significant advantages over the freshly cultured lymphocytes because it allows for lymphocyte samples to be collected in diverse geological locations and over extended periods of time and yet permits for the culture and assay of all the cell samples at exactly the same time.
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PMID:A method for detecting aryl hydrocarbon hydroxylase activities in cryopreserved human lymphocytes. 729 39