Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.1 (NADPH-diaphorase)
 3,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

NADH- and NADPH-diaphorases, 3alpha-, delta5-3beta-, 11beta- and 17beta-hydroxy-steroid dehydrogenases (HSD) and lipids were studied histochemically in the testes and adrenals of male bank voles kept in a long (16L:8D) or a short (8L:16D) photoperiod (Groups L and S, respectively). At 67 days of age the Group L males were heavier and had active and significantly larger testes than Group S males. The testes of Group S males were regressed and were also significantly smaller than those of 18-day-old animals born and reared in a 18L:6D photoperiod. Lipid droplets were detected in the Leydig cells and intratubular spaces in the testes of Group L animals, but were absent from those of Group S voles. The adrenal cortex of the Group L animals was virtually devoid of lipids, but large lipid inclusions were present in the basal zona fasciculata of the Group S voles. In the Group L testes the diaphorase activities were more intense and the difference in enzymic activity between the seminiferous epithelium and the Leydig cells was more pronounced (especially for NADH-diaphorase) than that in the testes of Group S animals. Moreover, the 3alpha-- and delta5-3beta-HSD activities were much stronger in the testes of sexually active animals; 17beta-HSD activity was present in the Leydig cells of the active testes, and absent in the regressed testes. There was no marked difference between the two groups of animals with regard to the distribution or intensity of diaphorases, 3alpha-, delta5-3beta-, 11beta- or 17beta-HSD in the adrenal cortex. It is concluded that a decline in steroid synthesis occurs in the testes of voles kept in a short photoperiod. The large lipid inclusions observed in the adrenal cortex of such animals suggest decreased corticosteroid synthesis and/or secretion.
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PMID:A histochemical study on the effects of photoperiod on gonadal and adrenal function in the male bank vole (Clethrionomys glareolus). 36 52

Cell-free extracts of a streptomycin-bleached strain of Euglena gracilis var. bacillaris have been examined for enzyme systems primarily responsible for the oxidation of reduced pyridine nucelotides. NADH lipoyl dehydrogenase, NADH and NADPH oxidase, NADH and NADPH diaphorase, and NADH and NADPH cytochrome c reductase have been demonstrated. The NADPH-linked enzymes had lower activity rates and were less sensitive to N-ethyl maleimide and p-hydroxymercuribenzoate than their NADH-linked counterparts. NADH cytochrome c reductase was the most sensitive to antimycin A. Michaelis-Menten constants (Km) determined were as follows: NADH diaphorase, 350 muM; NADPH oxidase 150 muM ; NADH lipoyl dehydrogenase, 0.35 muM. Enzyme activities after storage at -5 C indicate that the diaphorases are less labile than the other tested enzymes, and the differential activities of the NADH and NADPH linked enzymes suggest that functionally they may have different roles.
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PMID:Reduced pyridine nucleotide oxidases of Eugena gracilis var. bacillaris. 40 56

A study of the ultrastructural localization of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), glucose-6-phosphate dehydrogenase (G-6-PD), beta-hydroxybutyrate dehydrogenase (beta-HBD), NADH diaphorase (NADH-D) and NADPH diaphorase (NADPH-D) in the guinea-pig testis is reported. The procedures employed included short immersion or perfusion fixation with aldehydes followed by incubation of small blocks in a tetrazolium salt or a ferricyanide medium. The effects of incubation conditions were investigated, and a reaction medium for the ultracytochemical demonstration of 11 beta-HSD is described. Using suitable controls, evidence for the specificity of the cytochemical reactions is presented. It was found that all the enzymes studied were present in both the Leydig and Sertoli cells of the guinea-pig testis and that the intracellular distribution pattern for each enzyme was independent of the cell type. Using tetrazolium salt techniques, both 3 beta-HSD and 11 beta-HSD activities were localized on or in membranes of smooth endoplasmic reticulum and within the mitochondria. With the ferricyanide techniques, G-6-PD activity was found to be associated mainly with the smooth endoplasmic reticulum membranes, while beta-HBD activity was limited to mitochondria. With both the tetrazolium salt and ferricyanide techniques, the reaction products for NADH-D and NADPH-D activities showed localizations which were similar to those observed for the steroid dehydrogenases.
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PMID:The ultrastructural localization of the enzymes related to steroid hormone metabolism in the guinea-pig testis. 42 99

Rhodospirillum rubrum cell extracts have active NADP-reductase capable of catalyzing the diaphorase reaction in the presence of methyl viologene or benzyl viologene and NADPH-generating system. The greater part of NADP-reductase is localized in the soluble fraction of destroyed cells (90-10(3) g; 90 min). The purified preparation of NADP-reductase was found to contain 6 proteins, 4-5 of them possessing diaphorase activity. Partially purified NADP-reductase preparation with a period of half-inactivation of about two days has a molecular weight of 95 000 and absorption spectrum, characterized by two maxima at 410 and 430 nm. NADP-reductase preparation possesses also menadione-reductase activity, but showed no ability for transhydrogenase reaction and reduction of cytochrome c.
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PMID:[Purification and properties of Rhodospirillum rubrum NADP-reductase]. 81 42

Cytochrome b-559 was isolated from spinach and the alga Bumilleriopsis filiformis (Xanthophyceae) and characterized by functional properties: (a) It was active as electron acceptor in a diaphorase system using NADPH as donor and ferredoxin and ferredoxin-NADP reductase as redox proteins. (b) It exhibited photooxidation with Photosystem-I particles, when illuminated with 707 nm light. (c) It was photooxidized by Photosystem-II particles and 652 nm light at room temperature. Light greater than 702 nm was ineffective. The data corroborate previous reports on redox reactions of bound cytochrome b-559.
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PMID:Some photoreactions of isolated cytochrome b-559. 91 18

We have previously reported the isolation of old yellow enzyme complexed with a ligand of low molecular weight which imparts a distinctive charge-transfer absorption to the enzyme, making it green in color (Matthews, R. G., and Massey, V. (1969) J. Biol. Chem. 244, 1779-1789). This ligand has now been identified as p-hydroxybenzaldehyde by removal from the enzyme and characterization of its optical spectrum and subsequent mass spectral analysis. Similar compounds which are also bound to old yellow enzyme have been isolated from yeast extract and identified. These compounds give rise to complexes with old yellow enzyme which are characterized by broad long wavelength absorption bands, and they lead to inhibition of the NADPH-O2 oxidoreductase activity catalyzed by old yellow enzyme.
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PMID:Identification of p-hydroxybenzaldehyde as the ligand in the green form of old yellow enzyme. 119 84

A method is described for the preparation of synaptosomes and synaptosomal membranes from chicken brain. Procedures for isolating rat synaptosomal membranes could not be used directly; several modifications of existing procedures are reported. Purity of the subcellular and subsynaptosomal fractions was monitored by electron microscopy and measurements of ferrocytochrome c: oxygen oxidoreductase (EC 1.9.3.)), monoamine: oxygen oxidoreductase (deaminating) EC 1.4.3.4), rotenone-insensitive NADH: cytochrome c oxidoreductase (EC 1.6.99.3), NADPH: cytochrome c oxidoreductase (EC 1.6.99.1), orthophosphoric monoester phosphohydrolase (EC 3.1.3.2), ATP phosphohydrolase (EC 3.6.1.4), and levels of RNA. Microsomes are the main contaminant of the synaptosomal membrane fraction. Mitochondrial and lysosomal enzymes occur in lesser amounts. No myelin contamination was observed. Marker enzymes for contaminants suggest that these synaptosomal membranes are as pure as membranes described by others, and the specific activity of a neuronal membrane marker, (Na+ -K+)-activated ATPase, is as high as other preparations. Levels of this enzyme in the membrane fraction are enriched 13-fold over homogenate ATPase levels.
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PMID:Preparation of chick brain synaptosomes and synaptosomal membranes. 126 63

This is the first report of the presence of nitric oxide synthase (NOS) immunoreactivity and NADPH-diaphorase (NADPH-d) activity in a subpopulation of the intrinsic neurones that innervate the heart. A cytochemical technique to detect NADPH-d and antisera raised against purified rat cerebellar NOS were employed to examine the expression of these enzymes by cells in a dissociated cell culture preparation from newborn guinea-pig atria and interatrial septum. Comparison of the results obtained by these two techniques and double-labelling experiments indicate that a subpopulation of intracardiac neurones contain both NADPH-d and NOS. These results indicate that some intracardiac neurones are capable of synthesizing nitric oxide. This raises the possibility that nitric oxide plays a role in the neural control of the heart.
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PMID:Nitric oxide synthase immunoreactivity and NADPH-diaphorase activity in a subpopulation of intrinsic neurones of the guinea-pig heart. 127 80

Exposure of primary cultures of neonatal rat cortical astrocytes to bacterial lipopolysaccharide (LPS) results in the appearance of nitric oxide synthase (NOS) activity. The induction of NOS, which is blocked by actinomycin D, is directly related to the duration of exposure and dose of LPS, and a 2-hr pulse can induce enzyme activity. Cytosol from LPS-treated astrocyte cultures, but not from control cultures, produces a Ca(2+)-independent conversion of L-arginine to L-citrulline that can be completely blocked by the specific NOS inhibitor NG-monomethyl-L-arginine. The induced NOS activity exhibits an apparent Km of 16.5 microM for L-arginine and is dependent on NADPH, FAD, and tetrahydrobiopterin. LPS also induces NOS in C6 glioma cells and microglial cultures but not in cultured cortical neurons. The expression of NOS in astrocytes and microglial cells has been confirmed by immunocytochemical staining using an antibody to the inducible NOS of mouse macrophages and by histochemical staining for NADPH diaphorase activity. We conclude that glial cells of the central nervous system can express an inducible form of NOS similar to the inducible NOS of macrophages. Inducible NOS in glia may, by generating nitric oxide, contribute to the neuronal damage associated with cerebral ischemia and/or demyelinating diseases.
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PMID:Induction of calcium-independent nitric oxide synthase activity in primary rat glial cultures. 127 98

Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) of the rat brain, apparently identical with nitric oxide (NO) synthase, was demonstrated at the electron microscopic level by means of the tetrazolium salt 2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl)tetrazolium chloride (BSPT). BSPT is a non-osmiophilic compound that yields an insoluble, osmiophilic, and lipophobic formazan on reduction. The reaction product was deposited sharply on membranes of the endoplasmic reticulum including the nuclear envelope. Other membrane structures were, as a rule, free of reaction product, likewise mitochondria. Occasionally, however, the outer membrane of mitochondria was labeled, and their contents displayed a homogeneous, medium electron density. The findings suggest that NADPH-d, i.e. neuronal NO synthase, is a predominantly membrane-bound enzyme, which is ubiquitously distributed in cells of brain tissue, but highly concentrated in nerve cells described as 'NADPH-d-positive' at the light microscopic level.
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PMID:Nitric oxide synthase in rat brain is predominantly located at neuronal endoplasmic reticulum: an electron microscopic demonstration of NADPH-diaphorase activity. 128 94


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