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)

We have discovered cytochrome P450 and associated monooxygenase activities in microsomes prepared from spinal cord tissues from rats and a human. Cytochrome P450 levels and nicotinamide adenine dinucleotide phosphate cytochrome c reductase activities in microsomes from rat spinal cord were similar to those observed from the whole brain. However, certain monooxygenase activities were significantly lower in the rat spinal cord microsomes as compared to the corresponding activities observed in the whole brain. Cytochrome P450-mediated monooxygenase activities were also detectable in microsomes prepared from human spinal cord. Immunoblot analyses of rat and human spinal cord microsomes using antisera to various forms of hepatic cytochrome P450 namely (2B1 + 2B2), 1A1, 1A2 and 2E1 revealed the presence of immunologically similar forms. The spinal cord microsomes also cross-reacted with the antiserum to the phenobarbital-inducible form of rat brain cytochrome P450. Immunocytochemical stain was predominant in the gray horns of the rat spinal cord. At the cervical level, lamina 1 and 2 representing the substantia gelatinosa were intensely stained. In the ventral horns, lamina 7, 8 and 9 containing the large motor neurons were strongly labelled, while small neurons revealed variable staining. In the white matter, the glial cells were stained but the axons remained non-reactive.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cytochrome P450 and associated monooxygenase activities in the rat and human spinal cord: induction, immunological characterization and immunocytochemical localization. 747 69

The effect of chronic and in vitro ethanol exposure on brain oxygen radical formation and lipid peroxidation was analyzed. Ethanol induces a dose-dependent increase in lipid peroxidation in brain homogenates. The peroxidative effects of alcohol seem to be related to both cytochrome P450 and the ethanol-inducible form of cytochrome P450 (CYP2E1), because preincubation with metyrapone (an inhibitor of cytochrome P450) or with an antibody against CYP2E1 abolished the ethanol-increased lipid peroxidation. Using the formation of dichlorofluorescein, we also demonstrated that both in vitro and chronic alcohol exposure significantly enhanced the formation of oxygen radical species in synaptosomes. Chronic alcohol treatment also leads to an induction of cytochrome P450 (230%), NADPH cytochrome c reductase (180%), NADPH oxidation (184%), and CYP2E1 in brain microsomes. In addition, this treatment produced a decrease in the GSH/GSSG ratio in brain and significantly enhanced the levels of superoxide dismutase and catalase activities. This mechanism could be involved in the toxic effects of ethanol on brain and membrane alterations occurring after chronic ethanol intake.
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PMID:Ethanol-induced oxygen radical formation and lipid peroxidation in rat brain: effect of chronic alcohol consumption. 793 42

This study provides the first evidence that nitric oxide is released by astrocytes surrounding beta-amyloid plaques. Nitric oxide is involved in many neuropathological conditions and can have either a neuroprotective or a neurotoxic function depending on its concentration and the redox state of the tissue. It is produced by the enzyme nitric oxide synthase, which can be located by a simple histochemical technique for demonstrating NADPH diaphorase. Using this method we examined tissue from 10 brains where there were varying numbers of beta-amyloid plaques in the cerebral cortex. In the 6 brains with moderate or high densities of plaques, primitive and cored plaques were associated with between 1 and 10 reactive astrocytes that contained NADPH diaphorase or were immunoreactive for the inducible form of nitric oxide synthase. In the 4 brains which had only low densities of plaques, the plaques were not associated with diaphorase-containing astrocytes. The percentage of plaques associated with 1 or more NADPH diaphorase-containing astrocyte varied between 1 and 21% and was correlated with the density of plaques. Astrocytes were the only form of NADPH diaphorase-positive glial cell associated with the plaques. There was no evidence of any nitric oxide synthase occurring in microglia.
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PMID:Nitric oxide synthase in reactive astrocytes adjacent to beta-amyloid plaques. 916 28

Cytochrome P450 (P450) content and P450-mediated mono-oxygenase activities were measured in microsomes prepared from various regions of rat brain. The regional P450 content in brain varied between 0.1 and 0.15 nmol/mg of protein, with the brainstem and cerebellum showing the highest levels. NADPH cytochrome c reductase activity was highest in the cortex followed by cerebellum and brainstem as compared with the whole brain. Mono-oxygenase activities also varied among the various brain regions. Southern blot analysis of the cDNA synthesized from the poly(A)RNA isolated from rat brain regions and hybridized with cDNA to rat liver P4502B or P4502E1 revealed the presence of a transcript in untreated rat brain that had a molecular mass similar to that of the corresponding transcript from rat liver. Immunoblot analyses using antisera to purified rat liver P4502E1, P450(2B1/2B2), and a phenobarbital-inducible form of rat brain P450 revealed the presence of corresponding immunoreactive protein bands in all the brain regions examined. The present study demonstrated the diversity in the distribution of P450 and associated mono-oxygenase activities in brain and thus may reflect the differential capability of various regions of the brain to detoxify or bioactivate diverse xenobiotics.
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PMID:Expression of multiple forms of cytochrome P450 and associated mono-oxygenase activities in rat brain regions. 974 75