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)

The immunohistochemical localization of the neurotransmitter synthesizing enzymes choline acetyltransferase, tyrosine hydroxylase and dopamine-beta-hydroxylase was examined in the feline pontomesencephalic tegmentum. Examination of adjacent sections stained for either choline acetyltransferase, tyrosine hydroxylase or dopamine-beta-hydroxylase immunoreactivity, as well as individual sections doubly stained for both choline acetyltransferase and tyrosine hydroxylase immunoreactivity, unequivocally demonstrated that noradrenergic and cholinergic neurons were extensively intermingled in the brainstem tegmentum of the cat. This contrasts with the situation in various other species, where neurons utilizing these two neurotransmitters are discretely localized in distinct nuclei. Furthermore, the present studies demonstrate the existence of two types of choline acetyltransferase immunoreactive neurons in the feline tegmentum: the magnocellular neurons of the pedunculopontine and laterodorsal tegmental nuclei which stain histochemically for NADPH diaphorase, plus a population of small spindle-shaped neurons in the medial and lateral parabrachial nuclei which do not stain positively for NADPH diaphorase. The data are discussed with respect to several influential hypotheses of sleep cycle control.
Brain Res Bull 1987 Dec
PMID:Topographic relations of cholinergic and noradrenergic neurons in the feline pontomesencephalic tegmentum: an immunohistochemical study. 289 38

DT diaphorase [NAD(P)H:quinone oxidoreductase] activity was measured in subcellular fractions from homogenates of striatum, frontal cortex, hippocampus, cerebellum, hypothalamus and substantia nigra. This flavoprotein, which by definition oxidizes dihydronicotinamide adenine dinucleotide and dihydronicotinamide adenine dinucleotide phosphate at equal rates and is completely inhibited by 10(-5) M dicoumarol, was found to constitute 80-90% of the total dihydronicotinamide adenine dinucleotide- and dihydronicotinamide adenine dinucleotide phosphate-reductase activities in all brain regions studied. Antibodies raised against purified cytosolic DT diaphorase from the rat liver cross-reacted with the brain enzyme and inhibited soluble DT diaphorase from striatum and cerebellum to 80-90%. Immunohistochemical studies with the same antibodies demonstrated the occurrence of DT diaphorase immunoreactivity in a population of neurons in the substantia nigra and ventral tegmental area. In some neurons there was a colocalization of DT diaphorase and tyrosine hydroxylase-like immunoreactivity. The dense network of DT diaphorase-immunoreactive fibres in the striatum disappeared along with the dopaminergic innervation after 6-hydroxydopamine lesion. DT diaphorase immunoreactivity was also found in Bergmann glia, astrocytes and tanycytes. No correlation appeared to exist between the localization of neuronal DT diaphorase immunoreactivity and the dihydronicotinamide adenine dinucleotide phosphate-diaphorase-like activity, as defined by tetrazolium salt staining, used as a marker for certain peptidergic and cholinergic neurons. However, in, for example, glial cells in the cerebellum, DT diaphorase might contribute or be responsible for the histochemical dihydronicotinamide adenine dinucleotide phosphate-diaphorase activity.
Neuroscience 1988 Dec
PMID:Distribution of DT diaphorase in the rat brain: biochemical and immunohistochemical studies. 290 55

An enzyme analysis of diploid and triploid Paragonimus westermani was conducted using starch gel electrophoresis. In total, 16 enzymes, probably encoded by 18 loci, were studied for 3 populations of the diploid form sampled from 2 localities, and 4 populations of the triploid form from 4 localities. Comparison of the enzymes of the triploid and the diploid digeneans showed 5 different patterns: diaphorase (EC 1.6.2.2), glutamic-oxaloacetic transaminase (EC 2.6.1.1), hexokinase (EC 2.7.1.1), leucylglycylglycine aminopeptidase (EC 3.4.1.3), and phosphoglucomutase (EC 2.7.5.1). On the basis of the numbers of bands and their patterns, all individuals of the triploid are probably heterozygous at each of these 5 loci and homozygous at the remaining 13 loci. The occurrence of fixed heterozygotes found in triploid populations cannot be easily explained by only a single mutation. It is suggested that the variability may have been introduced by hybridization with a different sub-species or a closely related species and may, thus, have been maintained since the time of the origin of triploids.
Parasitology 1985 Dec
PMID:Electrophoretic studies on enzymes of diploid and triploid Paragonimus westermani. 293 81

NADH-diaphorase, succinate dehydrogenase (SDH), beta-hydroxybutyrate dehydrogenase (beta-HBDH), malate dehydrogenase (MDH) and cytochrome oxidase (CytO) were demonstrated histochemically in isolated perfused rat hearts during global ischaemia from 0 to 12 hours. The corresponding enzyme activities were measured when possible. The histochemically demonstrable activities of NADH-diaphorase and MDH decreased during the first hour of ischaemia. The time course of inactivation of biochemically detectable NADH-ferricyanide oxidoreductase was much the same as that of NADH-diaphorase. Both histochemically and biochemically detectable beta-HBDH gradually decreased by about 6 h of ischaemia. NADH-diaphorase but not MDH itself proved to be the rate-limiting factor when demonstrating MDH histochemically with nitroblue tetrazolium (NBT), whereas in the case of beta-HBDH the situation was probably the reverse. CytO and SDH activities did not change during the experimental period. Histochemistry clearly demonstrated ischaemic cellular injury, even though no significant diagnostic changes of ischaemia were visible by light microscopy. Even though this shows that enzyme-histochemical methods can be sensitive indicators of early ischaemic injury, in practice the time between the onset of injury and death as well as between death and autopsy must be taken into consideration when interpreting the results.
Br J Exp Pathol 1985 Dec
PMID:Correlations between enzyme histochemical reactions and respective enzyme activities in global ischaemic rat hearts. 300 15

Ferredoxin-NADP reductase from Euglena gracilis Klebs var. Bacillaris Cori purified to apparent homogeneity, yields a typical 36 kDa and an unusual 15 kDa polypeptide on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, exhibits a typical flavoprotein spectrum, contains FAD, and catalyzes NADPH-dependent iodonitrotetrazolium-violet diaphorase, NADPH-specific ferredoxin-dependent cytochrome-c-550 reductase and NADPH-NAD transhydrogenase activities. Rabbit antibody to the purified FNR blocks these activities specifically and also blocks the iodonitrotetrazolium-violet diaphorase activity of Euglena chloroplast completely. The low iodonitrotetrazolium-violet diaphorase activity in the plastidless mutant, W10BSmL, is mitochondrial and is not specifically blocked by the ferredoxin-NADP reductase antibody. Dark-grown non-dividing (resting) wild-type Euglena cells show a 4-fold increase in ferredoxin-NADP reductase activity during greening at 970 lx. Half of the low ferredoxin-NADP reductase activity in dark-grown cells is initially soluble, but by the end of chloroplast development nearly all of the enzyme is membrane-bound. The binding of ferredoxin-NADP reductase on exposure to light correlates with the extent of thylakoid membrane formation. Immunoblots of wild-type extracts during greening indicate that the 15 kDa polypeptide increases in the same manner as the extent of reductase binding to thylakoid membranes.
Biochim Biophys Acta 1987 Dec 17
PMID:Purification, properties, and cellular localization of Euglena ferredoxin-NADP reductase. 312 Jul 72

A nitroreductase enzyme has been isolated from Walker 256 rat carcinoma cells which can convert 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB 1954) to a cytotoxic DNA interstrand crosslinking agent by reduction of its 4-nitro group to the corresponding hydroxylamino species (Roberts JJ et al., Biochem Biophys Res Commun 140: 1073-1078, 1986; Knox RJ et al., Biochem Pharmacol 37: 4661-4669, 1988). The enzyme has now been identified as a form of NAD(P)H dehydrogenase (quinone) (DT diaphorase, menadione reductase (NMOR), phylloquinone reductase, quinone reductase, EC 1.6.99.2) by comparison of partial protein sequences, coenzymes, substrate and inhibitor specificities, and spectroscopic data. 2-Phenyl-5(4)-aminoimidazole-4(5)-carboxamide and 5(4)-aminoimidazole-4(5)-carboxamide were shown to be inhibitors of the isolated Walker cell enzyme. This observation could explain the reported antagonistic action of the aminoimidazole carboxamides to the antitumour effects of CB 1954.
Biochem Pharmacol 1988 Dec 15
PMID:The nitroreductase enzyme in Walker cells that activates 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB 1954) to 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide is a form of NAD(P)H dehydrogenase (quinone) (EC 1.6.99.2). 314 86

Fetal cortex from 16- and 17-day-old embryonic rats was transplanted into the parietal cortex of 12 adult rats rendered ischemic by temporary intraluminal occlusion of the middle cerebral artery. Ischemic injury in the host cortex adjacent to all nine surviving transplants was demonstrated with hematoxylin and eosin and cresyl violet strains. Nicotidamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemical studies revealed a normal number of NADPH-d-positive neurons, whereas acetylcholinesterase (AChE) staining revealed many more AChE-positive neurons in the transplants compared to the host parietal cortex. This could be due to: 1) selective survival of AChE neurons in the transplants compared to the host cortex; 2) increased expression of AChE in transplanted neurons; 3) induction of AChE in normally AChE-negative neurons; or 4) decreased transport of the AChE enzyme from the perikarya to fibers in surviving transplanted neurons. Many fibers positive for AChE and NADPH-d crossed between the host and transplant, although fiber density in the transplants was less than in normal host cortex. These results should encourage future investigation of whether similar transplants improve neurological function following experimental stroke.
J Neurosurg 1988 Dec
PMID:Neuronal changes in fetal cortex transplanted to ischemic adult rat cortex. 319 96

Walker tumour cells in vivo or in vitro are exceptionally sensitive to the monofunctional alkylating agent 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB 1954) (Cobb LM et al., Biochem Pharmacol 18: 1519-1527, 1969). CB 1954 forms DNA interstrand crosslinks in a time-dependent manner in Walker tumour cells but not in non-toxically affected Chinese hamster V79 cells [(Roberts JJ et al., Biochem Biophys Res Commun 140: 1073-1078, 1986)]. However, co-culturing Chinese hamster V79 cells with Walker cells in the presence of CB 1954 renders the hamster cells sensitive to CB 1954 and leads to the formation of interstrand crosslinks in their DNA, findings indicative of the formation by Walker cells of a diffusible toxic metabolite of CB 1954. A flavoprotein, of molecular weight 33.5 kDa as estimated by SDS-polyacrylamide gel electrophoresis, has been isolated from Walker cells and identified as a form of NAD(P)H dehydrogenase (quinone) (DT diaphorase, EC 1.6.99.2). This enzyme, in the presence of NADH or NADPH, catalyses the aerobic reduction of CB 1954 to 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide. This new compound can form interstrand crosslinks in the DNA of Chinese hamster V79 cells to which it is also highly toxic.
Biochem Pharmacol 1988 Dec 15
PMID:A new cytotoxic, DNA interstrand crosslinking agent, 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide, is formed from 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB 1954) by a nitroreductase enzyme in Walker carcinoma cells. 320 2

NADPH-diaphorase histochemistry selectively stains discrete populations of retinal interneurons in diverse mammals, including two amacrine types in the rabbit retina. In this study, we have demonstrated that most of these neurons show GABA-like immunoreactivity by combining indirect immunofluorescence and diaphorase histochemistry on frozen retinal sections. The NADPH-diaphorase amacrines account for only a small proportion of the GABA-positive cells in rabbit retina, thus reinforcing the emerging consensus that GABAergic amacrines are remarkably diverse in their morphology and function.
Brain Res 1988 Dec 06
PMID:GABA-like immunoreactivity in NADPH-diaphorase amacrine cells of the rabbit retina. 320 39

A simple colorimetric enzymatic assay for determination of serum 12 alpha-hydroxy bile acids was developed using 12 alpha-hydroxysteroid dehydrogenase (HSD). The enzymes were extracted from Bacillus sphaericus. The principle of the method is as follows: 12 alpha-hydroxy bile acids are converted to 12-oxo bile acids using 12 alpha-HSD with the conocomitant reduction of NAD to NADH, and then the hydrogen of the generated NADH is transferred by diaphorase to NTB to yield diformazan. Finally, the color of resultant diformazan was measured. The specificity and precision of this assay method were satisfactory. A linear relationship was noted between the amount of 12 alpha-hydroxy bile acids and the degree of absorbance in the range of 6.7 to 215 microM. The fasting values for serum 12 alpha-hydroxy bile acid in 10 patients with liver diseases ranged widely from 7.6 to 91.1 microM, and values obtained with this assay agreed closely with those obtained by gas-liquid chromatography (r = 0.94, p less than 0.001). The assay is convenient, rapid, and specific for the measurement of 12 alpha-hydroxy bile acid concentrations in the serum of patients with liver diseases.
Gastroenterol Jpn 1988 Dec
PMID:Enzymatic determination of serum 12 alpha-hydroxy bile acid concentration with 12 alpha-hydroxysteroid dehydrogenase. 322 Feb 41


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