Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.5.2 (NQO1)
 6,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activities of alkaline phosphatase, NAD diaphorase and NADP diaphorase increased in infantile mouse ovaries in response to injected gonadotrophins. The distribution and activity of these enzymes were studied in detail in the ovaries of normal mice from 1 to 41 days after birth and in mice injected at various ages with FSH, LH and HCG. Granulosa cells contained NAD and NADP diaphorases. Thecal cells contained NADP diaphorase and alkaline phosphatase with NAD diaphorase first appearing in the thecae of larger follicles 11 days after birth. All three enzymes occurred in interstitial tissue, in the interfollicular stroma and in groups of gonadotrophin-responsive cells in the medulla. These medullary cells and the interstitial tissue were stimulated by exogenous LH and HCG but not by FSH. Granulosa, theca and interfollicular tissue were stimulated at some stage by each of the three injected hormones. The normal pattern of development is discussed in relation to the changing serum levels of endogenous gonadotrophin found in similar mice. It is concluded that the enzyme changes were closely and reciprocally related to endogenous hormone concentrations.
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PMID:Histochemical studies on three gonadotrophin-responsive enzymes in the infantile mouse ovary. 112 17

The activity of 19 enzymes (hexokinase, glucoso-6-phosphatisomerase, alpha-glycerophosphate-, lactate-, succinate-, isocitrate-, malate-, glucoso-6-phosphate-, 6-phosphogluconate-, glutamate-, alcohol-, inosine-5'-phosphate-, guanosine-5'-monophosphate-dehydrogenase, cytochromoxidase NAD.N2- and NADP.N2-diaphorase, monoaminoxidase, alkaline and acid phosphatase) was studied comparatively in the mucosa of control rats and in tumors of the small intestine (27), and large intestine (176), induced in 41 rats percutaneously by 1,2-dimethylhydrazine. A decreased level of the enzymes of tissue respiration and Krebs cycle was found with a simultaneous increase in the activity of the enzymes of glycolysis and pentoso-monophosphate shunt. These data evidence variations in tumor metabolism consisting in oxidizing phosphorylation, being replaced by aerobic glycosis, and also reflecting an intensive proliferation of tumor cells.
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PMID:[An enzymohistochemical study of experimental tumors of the intestine]. 123 60

Male F344/NCr rats were exposed to low dietary concentrations of Aroclor 1254 (0-33 ppm) for 7 days, following which the induction of selected hepatic drug metabolizing enzymes was monitored. CYP1A1, measured indirectly by assaying the O-dealkylation of ethoxyresorufin in 9000 g supernatants, was increased 1.5-, 3-, 8-, and 37-fold following 7 days of exposure to 1.0, 3.3, 10, and 33 ppm Aroclor, respectively. In contrast, the O-dealkylation of benzyloxyresorufin, an indirect measure of CYP2B1 activity, was increased approximately 4-fold following exposure to 33 ppm dietary Aroclor. Measurement of the non-P450-mediated activities epoxide hydrolase, DT-diaphorase, and aldehyde dehydrogenase (NADP+, benzaldehyde) revealed < 4-fold inductions following feeding of 33 ppm Aroclor. In view of the relatively high sensitivity of the CYP1A-specific catalytic endpoint as a biomarker for Aroclor exposure, alternative endpoints for detecting induction of this subfamily of P450 were also examined. The extent of in vivo CYP1A induction was assessed by measuring serum concentrations of zoxazolamine 150 min following an intraperitoneal dose of 100 mg/kg body wt. Slight decreases in serum zoxazolamine concentration were observed in rats exposed to as little as 1.0 ppm dietary Aroclor 1254, while profound decreases were seen in rats exposed to > or = to 10 ppm Aroclor. Immunodetection of CYP1A1 protein, with a monoclonal antibody directed against this cytochrome, revealed a 2.9-fold increase in rats exposed to as little as 1.0 ppm Aroclor, and approximately 10- and 44-fold increases following exposure to 3.3 and 10 ppm dietary Aroclor, respectively. Increases in total hepatocellular RNA coding for CYP1A1 and CYP1A2, quantified by hybridization to specific oligonucleotide probes, corresponded well to the increases in hepatic O-dealkylase activity for ethoxyresorufin (CYP1A1) and methoxyresorufin (CYP1A2), respectively. Thus, CYP1A induction, directly or indirectly measured with a variety of endpoints, represents a highly sensitive biomarker for exposure to relatively low doses of Aroclor 1254 in the rat.
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PMID:Induction of hepatic CYP1A in male F344/NCr rats by dietary exposure to Aroclor 1254: examination of immunochemical, RNA, catalytic, and pharmacokinetic endpoints. 128 48

Nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry was utilized to localize nitric oxide synthase (NOS), and thus sites where nitric oxide (NO) can be synthesized, within peripheral nervous system perikarya and fibers. Recent studies suggest that NO relaxes vascular and non-vascular smooth muscle. In this study, the origin and distribution of NADPH-diaphorase perikarya and fibers in the rat urinary bladder were examined. Results suggest that a small number of NADPH-diaphorase-positive perikarya are present within the bladder wall and within adjacent small ganglia. In addition, NADPH-diaphorase-positive nerve fibers were observed in the adventitial and muscular layers, subjacent to the urothelium and as perivascular fibers. After injection of the retrograde tracer fluorogold (FG) into the bladder wall, numerous FG-labeled perikarya in the major pelvic ganglia and the T13-L2, L6 and S1 dorsal root ganglia were NADPH-diaphorase positive. However, none of the FG-labeled perikarya in the inferior mesenteric ganglia were NADPH-diaphorase positive. The prevalence of NADPH-diaphorase-positive perikarya and fibers suggests that NO may serve a role in bladder function.
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PMID:Origin and distribution of NADPH-diaphorase-positive neurons and fibers innervating the urinary bladder of the rat. 128 92

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

Mycotic foci were studied histochemically on various experimental models of candidiasis. NAD-H, NADP-H-diaphorase, acid phosphatase and ATPase were revealed in the fungi, the activity of these enzymes depended on the state of the fungus. Diaphorase activity in the mucous membrane epithelium falls only if it is damaged by massive invasion of pseudo-mycelium. Inhibition of the enzyme activity in the visceral foci (kidney, liver, heart) occurs only in case of pronounced destruction and is not observed at the distance from the fungi. The results do not confirm the idea of fungal secretion of mycotoxins penetrating into the surrounding tissues and damaging them.
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PMID:[Histochemical study of lesions in superficial and visceral candidiasis]. 129 70

An enzymatic cycling procedure for beta-NADP+ generated by the enzyme 3'-phosphodiesterase, 2':3'-cyclic nucleotide (EC 3.1.4.37) from its substrate 2':3'-cyclic NADP+ is described. The enzymes glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and diaphorase (EC 1.8.1.4) are used to cycle the cofactor between its oxidized and reduced forms in the presence of glucose-6-phosphate and p-iodonitrotetrazolium violet (INT) with the concomitant production of colored INT-formazan, monitored at 492 nm. The amplification is about 400-fold per hour and is sensitive enough to detect 6 x 10(-13) mol of NADP(H). A simple procedure for the optimization of this cycling assay is also described. Conjugates to 3'-phosphodiesterase, 2':3'-cyclic nucleotide may be used in heterogeneous enzyme immunoassays for the detection of small quantities of haptens or proteins in biological fluids.
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PMID:An enzymatic cycling procedure for beta-NADP+ generated by 3'-phosphodiesterase, 2':3'-cyclic nucleotide. 132 Mar 51

Nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) staining of striatal neuropil showed inhomogeneities in human fetal and adult brains. Highly reactive patches were seen during fetal and neonatal period, distributed in a lighter stained background matrix. In adult, zones of low NADPH-d reactivity appeared against darker background staining. NADPH-d reactive patches corresponded to and showed a similar shift in the intensity of staining during development as acetylcholinesterase (AChE) reactive striosomes.
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PMID:Compartmentalization of NADPH-diaphorase staining in the developing human striatum. 140 89

Ferredoxin-NADP+ reductase from the cyanobacterium Anabaena sp. PCC 7119 was chemically modified by the alpha-dicarbonyl reagent phenylglyoxal. The studies of the inactivation by this compound, which is specific for arginyl residues, of both the diaphorase and NADPH-cytochrome c reductase activities, characteristic of the enzyme, are indicative of the involvement of at least one group of this kind in the binding site of NADP+ and a second one implicated in the interaction with ferredoxin. After specific cleavage of a FNR sample incubated with [7-14C]phenylglyoxal, two major labeled peptides were identified. The peptide which exhibited the higher degree of modification corresponded to residues 208-242. It contained four arginine residues but only two of them were the target of the modification: Arg224 and Arg233. Protection studies with protein substrates and sequence comparison with other reductases allow us to propose that these residues in Anabaena sp. PCC 7119 FNR must be involved in the interaction with the pyridine nucleotide. The second peptide corresponds to residues 75-103 and although it contains three arginine residues, Arg77 is the only one that exhibits the modification. This residue seems to be a key one in the interaction of this reductase with ferredoxin.
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PMID:Identification of arginyl residues involved in the binding of ferredoxin-NADP+ reductase from Anabaena sp. PCC 7119 to its substrates. 144 67

Ferredoxin-NADP+ reductase from Anabaena sp. PCC 7119 is chemically modified by pyridoxal 5'-phosphate. The incorporation of 2 +/- 0.3 mol pyridoxal 5'-phosphate/mol ferredoxin-NADP+ reductase inhibited NADPH-cytochrome c reductase activity by up to 95% while 55% of diaphorase activity still remained. Considerable protection against inactivation was afforded by ferredoxin. Chymotryptic cleavage of the modified enzyme was performed, the peptides were separated by high performance liquid chromatography, and the peptides containing pyridoxamine 5'-phosphate were identified by their fluorescence and by their absorbance at 325 nm. Three major labelled peptides were found. Their sequences were comprised of residues 46-54, 231-235 and 289-295. Lys-53 and -294 were the residues which presented the highest degree of modification and seem to be involved in the ferredoxin binding site of ferredoxin-NADP+ reductase from Anabaena sp. PCC 7119.
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PMID:Lysine residues on ferredoxin-NADP+ reductase from Anabaena sp. PCC 7119 involved in substrate binding. 154 17


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