Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

We have previously reported that stimulation of astrocyte cultures by particular agonists and calcium ionophores induces cyclic GMP formation through activation of a constitutive nitric oxide synthase (NOS) and that astrocytes from cerebellum show the largest response. In the present work we have used rat cerebellar astrocyteenriched primary cultures to identify and characterise the isoform of NOS expressed in these cells. The specific NOS activity in astrocyte homogenates, determined by conversion of [3H]arginine to [3H]citrulline, was ten times lower than in homogenates from cerebellar granule neurons. Upon centrifugation at 100,000 g, the astroglial activity was recovered in the supernatant, whereas in neurons around 30% of the activity remained particulate. The cytosolic NOS activities of both astrocytes and granule neurons displayed the same Km for L-arginine, dependency of calcium, and sensitivity to NOS inhibitors. Expression of NOS-I in astrocyte cytosolic fractions was revealed by Western blot with a specific polyclonal antiserum against recombinant NOS-I. Double immunofluorescence labelling using anti-glial fibrillary acidic protein (GFAP) and anti-NOS-I antibodies revealed that a minor population of the GFAP-positive cells, usually in clusters, presented a strong NOS-I immunostaining that was predominantly located around the nuclei and had a granular appearance, indicating association with the endoplasmic reticulum-Golgi system. Astrocytes of stellate morphology also showed immunoreactivity in the processes. Similar staining was observed with the avidin-biotin-peroxidase complex using different anti-NOS-I antisera. With this method the majority of cells showed a weak NOS-I immunoreactivity around the nuclei and cytosol. A similar pattern was observed with the NADPH-diaphorase reaction. These results demonstrate that the NOS-I expressed in astrocytes presents the same biochemical characteristics as the predominant neuronal isoform but may differ in intracellular location.
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PMID:Characteristics of nitric oxide synthase type I of rat cerebellar astrocytes. 891 54

NADPH-diaphorase positive (NDP) neurons and nerve fibers were found in the spinal dorsal horn (DH) and sensory ganglia of the turtle Chrysemys d'orbigny. Three well-defined types of NDP neurons were found in the DH: (a) elongated nerve cells with two radially arranged dendritic branches, (b) neurons with rostrocaudal dendritic branches, (c) bitufted neurons with two, practically symmetric branches that project to the ipsilateral and contralateral dorsal horns. A combination of the techniques that reveal NADPH-diaphorase activity with the horseradish peroxidase transganglionic labeling of the dorsal root collaterals, suggested that NDP neurons of the DH are second-order cells of the spinal sensory pathway. NDP neurons were also found in the spinal sensory ganglia at all metameric levels. Our findings indicate that the DH of turtles, like that of mammals, contains both the enzymatic machinery and the neural connections required to postulate the participation of nitric oxide in "plastic phenomena" such as hyperalgesia and central sensitization. Two other alternatives or complementary hypotheses are discussed: (a) NDP neurons in the DH and sensory ganglia may represent specific cell populations involved in the processing of sensory visceral information; (b) NADPH-diaphorase reactivity may indicate sustained levels of neuronal activity.
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PMID:Localization of NADPH-diaphorase containing neurons in the spinal dorsal horn and spinal sensory ganglia of the turtle Chrysemys d'orbigny. 910 12

Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity and the central terminal fields of branches of the mandibular and chorda tympani nerves were visualized histochemically at the same time using transganglionic transport of wheat germ agglutinin conjugated with horseradish peroxidase. The blue NADPH-d-positive neurons comprised a sparse network in the dorsomedial spinal trigeminal subnucleus oralis and a dense one in the rostral lateral division of the nucleus of the solitary tract. In the subnucleus caudalis, most labeled neurons were in the superficial zone, and smaller numbers were in the magnocellular zone. The NADPH-d-positive neurons in the subnucleus oralis and the nucleus of the solitary tract overlapped mostly with the transganglionically labeled terminal field from the lingual nerve, partly with the terminal field from the inferior alveolar and chorda tympani nerves, and rarely with the terminal field from the mental nerve. The NADPH-d-positive neurons in the dorsomedial paratrigeminal nucleus and subnucleus caudalis overlapped mostly with the terminal field from the lingual nerve, partly with the terminal field from the inferior alveolar and mental nerves and never with the terminal field from the chorda tympani. A statistically significant reduction in the number of NADPH-d-positive neurons was seen bilaterally in subnucleus oralis and the nucleus of the solitary tract when the lingual nerve was transected. Inflammatory insults to the lingual nerve or tooth pulps significantly increased the number of NADPH-d-positive neurons in subnucleus oralis, the nucleus of the solitary tract, and subnucleus caudalis. These results show that the NO/cyclic GMP system in the trigeminal and solitary nuclei is differentially regulated trans-synaptically by trigeminal afferents depending on the nucleus and sensory modality.
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PMID:Central terminals of orofacial primary afferents and NADPH-diaphorase activity in the trigemino-solitary complex of rats. 950 70

Afferent projections to the mediodorsal and anterior thalamic nuclei in the cat were studied by means of stereotaxic injection of neuronal tracers (horseradish peroxidase and fluorochromes). Acetylcholinesterase reaction was studied, as well as horseradish peroxidase and NADPH-diaphorase colocation in neuronal bodies which send and receive projections to and from the mediodorsal thalamic nucleus. Based on the connectivity and histochemistry findings, the possibility that prion agents responsible for fatal familial insomnia spread from the mediodorsal and anterior thalamic nuclei through a retrograde pathway is discussed. The possible pathophysiological implication of nitrergic systems in fatal familial insomnia is also considered.
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PMID:Afferent projections to the mediodorsal and anterior thalamic nuclei in the cat. Anatomical-clinical correlations. 966 6

In the present study, histochemical techniques combined with more conventional anatomical methods were used to refine the identification of the nucleus of the optic tract and the nuclei of the accessory optic system in the opossum. The distribution of the enzyme cytochrome oxidase (CO) was examined in the cells and the neuropil of the opossum's mesodiencephalic region. Strong CO labeling was present in the nucleus of the optic tract (NOT)-dorsal terminal nucleus (DTN). Alternate sections, taken from animals that had received bilateral injections of horseradish peroxidase centered in the region of the inferior olive, were subjected to assays for CO and horseradish peroxidase. The region occupied by CO-labeled cells in the NOT-DTN superimposed with the one defined by retrogradely labeled cells. Cell counts along the NOT-DTN anteroposterior axis revealed that although the olivary and CO-positive cells were confined within similar boundaries, the latter are up to twofold more numerous than the former. As revealed by cytochrome oxidase histochemistry, the outlines of the NOT-DTN, the other pretectal nuclei and the nuclei belonging to the accessory optic system coincided with those revealed by the histochemistry for nicotinamide dinucleotide phosphate diaphorase (NADPH-d). After an intraocular injection of cholera toxin beta subunit and alternate sections processing for NADPH-d and CO, the distribution of labeled retinal terminal fields in the mesodiencephalic region was shown to be coincident with regions of high levels of histochemical labeling. These results are discussed in the light of previous anatomofunctional assessments of the pretectum and accessory optic system.
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PMID:Cytochrome oxidase and NADPH-diaphorase on the afferent relay branch of the optokinetic reflex in the opossum. 970 May 67

The accessory olfactory bulb (AOB) is a primary center of the vomeronasal system. In the dog, the position and morphology of the AOB remained vague for a long time. Recently, the morphological characteristics of the dog AOB were demonstrated by means of lectin-histochemical, histological, and immunohistochemical staining, although the distribution of each kind of neuron, especially granule cells, remains controversial in the dog AOB. In the present study, we examined the distribution of neuronal elements in the dog AOB by means of immunohistochemical and enzyme-histochemical staining. Horizontal paraffin or frozen sections of the dog AOB were immunostained with antisera against protein gene product 9.5 (PGP 9.5), brain nitric oxide synthase (NOS), glutamic acid decarboxylase (GAD), tyrosine hydroxylase (TH), substance P (SP), and vasoactive intestinal polypeptide (VIP) by avidin-biotin peroxidase complex method. In addition, frozen sections were stained enzyme-histochemically for NADPH-diaphorase. In the dog AOB, vomeronasal nerve fibers, glomeruli, and mitral/tufted cells were PGP 9.5-immunopositive. Mitral/tufted cells were observed in the glomerular layer (GL) and the neuronal cell layer (NCL). In the NCL, a small number of NOS-, GAD-, and SP-immunopositive and NADPH-diaphorase positive granule cells were observed. In the GL, GAD-, TH-, and VIP-immunopositive periglomerular cells were observed. In the GL and the NCL, TH-, and VIP-immunopositive short axon cells were also observed. In addition to these neurons, TH- and SP-immunopositive afferent fibers were observed in the GL and the NCL. We could distinctly demonstrate the distribution of neuronal elements in the dog AOB. Since only a small number of granule cells were present in the dog AOB, the dog AOB did not display such a well-developed GCL as observed in the other mammals.
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PMID:Immunohistochemical and enzyme-histochemical study on the accessory olfactory bulb of the dog. 981 Dec 17

Generalized tonic-clonic seizures of brain stem origin in rats are associated with acute induction of neuronal Fos in several discrete regions of the brain. One particular site in the dorsal pons shows remarkable Fos induction following generalized tonic seizures induced by maximal electroshock in normal rats or by audiogenic stimulation in genetically epilepsy-prone rats (GEPRs). Although this area shows the most intense Fos induction of any brain area following generalized tonic seizures, its identity has been uncertain. Based on its general location, we hypothesized that this nucleus was either 1) a component of the pedunculopontine tegmentum nucleus-pars compacta (PPTn-pc) or 2) the superior lateral subnucleus of lateral parabrachial area (LPBsl). The present study used Fos-protein immunocytochemistry in combination with the reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry, cholecystokinin (CCK) immunocytochemistry, and neuronal tract-tracing to determine the identity of this cluster of Fos-immunoreactive neurons in the dorsal pons. Following maximal electroshock seizure (MES), Fos labeling was compared to NADPH diaphorase staining (a marker for cholinergic neurons of the PPTn-pc); retrograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injected into the ventromedial nucleus of the hypothalamus (VMH; to identify the LPBsl) or CCK immunoreactivity (also a marker for LPBsl neurons). Results showed this cluster of Fos immunoreactive (FI) neurons to be closely associated, but not overlapping, with the lateral and most caudal aspect of the PPTn-pc. Alternatively, WGA-HRP retrograde-labeled neurons corresponded precisely with the seizure-induced FI neurons. Additionally, the location of CCK immunoreactive neurons directly overlapped with the FI neurons, although they were not nearly as prevalent. These results demonstrate that the seizure-induced FI neurons in this area are neurons of the LPBsl and not cholinergic neurons of the PPTn-pc. This is the first report of seizure-induced Fos expression specifically localized to the superior lateral subnucleus of the lateral parabrachial area.
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PMID:Expression of Fos in the superior lateral subdivision of the lateral parabrachial (LPBsl) area after generalized tonic seizures in rats. 982 Jul 33

2-Amino-3-carboxy-1,4-naphthoquinone, discovered as a novel bifidogenetic growth stimulator (BGS), has been characterized by determination of redox and acid-base equilibria, partition properties, and UV-vis and electron spin resonance spectral properties. BGS is proposed to function as an electron transfer mediator from NADH to O2. BGS is reduced by NADH-reduced diaphorase (or related enzymes) and the reduced BGS is reoxidized by autoxidation and a peroxidase-catalyzed reaction. The proposed reaction would spare pyruvate as an important metabolic intermediate, and minimize the cytotoxic effects of H2O2 generated by the autoxidation. Kinetic studies were performed in model enzymatic systems using 2-methyl-1,4-naphthoquinone (VK3) as a reference compound with a very weak growth-stimulating effect. The results support our proposal and reveal the superiority of BGS to VK3 as an electron transfer mediator in the proposed reactions.
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PMID:Mechanistic study on the roles of a bifidogenetic growth stimulator based on physicochemical characterization. 983 15

The distribution and the morphology of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase (ND)-active and neuronal nitric oxide synthase (NOS)-immunoreactive neurons and fibers were studied in the olfactory bulb of three species of primates, i.e., the cynomolgus macaque monkey (Macaca fascicularis), the Japanese macaque monkey (Macaca fuscata), and the pig-tail macaque monkey (Macaca nemestrina). The ND staining was carried out by means of a direct histochemical method with beta-NADPH as cosubstrate and nitro blue tetrazolium as chromogen. The NOS immunostaining was carried out by using a polyclonal antibody and the avidin-biotin peroxidase method. Similar results were found in the three species, where a distinct distribution pattern of ND/NOS-stained neurons and fibers was observed. All olfactory fibers demonstrated ND-positive labeling but they were NOS-immunonegative. In the superficial modulatory area of the olfactory bulb, a few weakly ND- and NOS-positive periglomerular cells, stellate cells, and darkly stained superficial short-axon cells were observed. In the inframitral layers, granule cells, deep stellate cells, and deep short-axon cells were distinguished. Short-axon cells had oriented morphologies and spiny dendrites. Many thick, varicose ND/NOS-stained fibers identified as centrifugal fibers were observed in the white matter, granule cell layer, internal plexiform layer, mitral cell layer, and external plexiform layer. This distribution of ND activity and NOS immunoreactivity showed similarities to and differences from what has been reported in the olfactory bulb of macrosmatic mammals including rodents (rat, mouse, and hamster) and insectivores (hedgehog). These data confirm that the complexity of the ND/NOS staining in the olfactory bulb of one species correlates with the importance of olfaction in the biology of such species.
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PMID:Chemical anatomy of the macaque monkey olfactory bulb: NADPH-diaphorase/nitric oxide synthase activity. 985 8

Dihydrolipoamide dehydrogenase (LADH) lipoamide reductase activity decreased whereas enzyme diaphorase activity increased after LADH treatment with myeloperoxidase (MPO) dependent systems (MPO/H2O2/halide, MPO/NADH/halide and MPO/H2O2/nitrite systems. LADH inactivation was a function of the composition of the inactivating system and the incubation time. Chloride, iodide, bromide, and the thiocyanate anions were effective complements of the MPO/H2O2 system. NaOCl inactivated LADH, thus supporting hypochlorous acid (HOCl) as putative agent of the MPO/H2O2/NaCl system. NaOCl and the MPO/H2O2/NaCl system oxidized LADH thiols and NaOCl also oxidized LADH methionine and tyrosine residues. LADH inactivation by the MPO/NADH/halide systems was prevented by catalase and enhanced by superoxide dismutase, in close agreement with H2O2 production by the LADH/NADH system. Similar effects were obtained with lactoperoxidase and horse-radish peroxidase supplemented systems. L-cysteine, N-acetylcysteine, penicillamine, N-(2-mercaptopropionylglycine), Captopril and taurine protected LADH against MPO systems and NaOCl. The effect of the MPO/H2O2/NaNO2 system was prevented by MPO inhibitors (sodium azide, isoniazid, salicylhydroxamic acid) and also by L-cysteine, L-methionine, L-tryptophan, L-tyrosine, L-histidine and reduced glutathione. The summarized observations support the hypothesis that peroxidase-generated "reactive species" oxidize essential thiol groups at LADH catalytic site.
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PMID:Inactivation of myocardial dihydrolipoamide dehydrogenase by myeloperoxidase systems: effect of halides, nitrite and thiol compounds. 1019 78


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