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)

Administration of hepatotoxic doses of allyl alcohol and N-hydroxy-2-acetylaminofluorene (N-OH-AAF) TO adult male rats produced periportal necrosis and functional derangement of the hepatic endoplasmic reticulum within 24 h. The rates of N-demethylation of ethylmorphine and p-hydroxylation of aniline were decreased 6 h following allyl alcohol administration, but cytochromes P-450 and b5 were unchanged. In contrast, administration of NOH-AAF decreased cytochromes P-450 and b5 and the rate of aniline p-hydroxylation, but did not change the rate of N-demethylation of ethylmorphine or the activities of cytochrome c reductase and glucose-6-phosphatase. No decrease was observed in the activity of the cytosol enzyme, DT diaphorase, following allyl alcohol treatment. The changes by these periportal hepatotoxins were compared with those produced both by central and midzonal hepatotoxins and with changes occurring in the liver after surgical partial hepatectomy.
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PMID:Biochemical changes after hepatic injury by allyl alcohol and N-hydroxy-2-acetylaminofluorene. 18 70

Studies have been made of the morphology, enzyme activity and protein composition of liver endoplasmic reticulum in rats exposed to acute doses of the carcinogen, 2-acetylaminofluorene (2-AAF). Electron microscopic examination revealed numerous ultrastructural changes in the hepatocyte; most consistent alterations were the disorganisation of endoplasmic reticulum system with apparent increase of smooth endoplasmic reticulum. Administration of 2-AAF to rats immediately depressed microsomal glucose-6-phosphatase activity and eventually induced epoxide hydratase activity 6--7-fold over control activity. The induction was time-dependent and maximal rates of induction were observed at dosages greater than 40 mg/kg body wt. The treatment also induced cytochrome b5 content, NADH and NADPH cytochrome c reductase activities (1.0--1.5-fold). Only very small changes in the total content of cytochrome P-45- were noted. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of microsomal proteins from 2-AAF pretreated animals showed time-dependent induction of two polypeptides which differed slightly in migration, in the region of Mr = 48000; the fast-migrating induced polypeptide has been identified as epoxide hydratase. Two-dimensional PAGE analysis of microsomal proteins from 2-AAF exposed rats showed a reproducible deletion of a protein with molecular weight in the region of 67000. The basis for the alterations in the protein composition of endoplasmic reticulum in response to 2-AAF treatment is discussed.
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PMID:Alterations in the enzyme activity and polypeptide composition of rat hepatic endoplasmic reticulum during acute exposure to 2-acetylaminofluorene. 707 8

The dietary administration of beta-carotene (BC; 100 mg/kg food) daily has been found to be highly effective in reducing cancer incidence in male Sprague-Dawley rats fed 2-acetyl-aminofluorene (0.05% in food). BC treatment either before initiation, during initiation and selection/promotion phases of hepatocarcinogenesis have been found to be effective in elevating hepatic microsomal cytochrome b5 (24-50%), P-450 (18-38.5%), NADPH cytochrome c reductase (17.5-43.25%) and cytosolic aryl hydrocarbon hydroxylase (60.5-63.5%) activity to a statistically significant level measured either in the hyperplastic nodule (HN) or in the non nodular surrounding liver parenchyma (NNSP) compared to carcinogen control. Moreover, BC treatment throughout the study decrease the cytosolic 1-chloro-2,4-dinitrobenzene conjugated glutathione S-transferase (38.9-51.22%) and microsomal UDP-glucuronyl transferase (37.3-59.1%) activities to a significant level when compared to carcinogen control rats. A decrease in the number of hyperplastic nodules and their total liver parenchyma occupied were also observed in BC treated groups. Furthermore, a direct correlation between HNs and NNSP liver areas were observed with the hepatic BC and vitamin A contents and also with the rates and patterns of hepatic drug metabolism. Our results confirm the fact that BC is particularly protective in limiting the action of 2-AAF during the initiation phase of hepatocarcinogenesis.
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PMID:Inhibitory effect of beta-carotene on chronic 2-acetylaminofluorene induced hepatocarcinogenesis in rat: reflection in hepatic drug metabolism. 820 68