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)

Incubation of aldehyde dehydrogenase-free mitochondrial preparations with biogenic amines serotonin, tyramine, 2-phenylethylamine and 5-methoxytryptamine resulted in inhibition of enzymes activity of both outer (rotenone-insensitive NADH-cytochrome c reductase) and inner (succinate dehydrogenase, succinate cytochrome c reductase) mitochondrial membranes. Solubilization of mitochondria after the incubation did not influence the amine-induced alteration of succinate dehydrogenase activity. Pretreatment of the organelles with a mixture containing chlorgyline and deprenyl completely inhibited monoamine oxidase (MAO) activity and prevented the effects of all the amines studied on mitochondrial enzymes. MAO-dependent effects of 5-methoxytryptamine were fully reproduced by 5-methoxyindolyl-3-acetaldehyde (one of probable products of 5-methoxytryptamine deamination). The effect of the aldehyde was not prevented by chlorgyline and deprenyl. After selective inhibition of MAO-A by chlorgyline the order of MAO-B-dependent effects of biogenic amines on mitochondrial enzymes studied was as follows: tyramine greater than or equal to 2-phenylethylamine much greater than serotonin. In deprenyl pretreated mitochondria the potency of MAO-A-dependent effects of these amines was: serotonin greater than tyramine much greater than much greater than 2-phenylethylamine. The data obtained suggest that the product(s) of oxidative deamination of biogenic amines (probably the aldehydes) catalyzed by both types of MAO (MAO-A and MAO-B) are able to regulate the energy functions of mitochondria.
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PMID:[The role of monoamine oxidase in the regulation of mitochondrial energy functions]. 175 90

The ultrastructure of reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase-positive neurons in cat cerebral cortex, amygdala and caudate nucleus was investigated by electron microscopy using a modified method applicable to aldehyde-fixed tissues. These NADPH diaphorase-positive neurons were morphologically similar to neurons immunohistochemically positive for somatostatin. They had large amounts of electron-dense formazan reaction products scattered through the whole cytoplasm but not in the mitochondria or nucleus. Similar electron-dense reaction products were visible in the dendrites of these neurons. The results indicate that NADPH diaphorase histochemistry is a useful method for the ultrastructural examination of particular groups of neurons.
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PMID:Ultrastructure of reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase-positive neurons in the cat cerebral cortex, amygdala and caudate nucleus. 340 36

Up to now, more than 40.000 determinations of urinary estrogens (E1 + E2) have been carried out in routine clinical analysis by the enzymatic method using estradiol dehydrogenase. This method makes use of the transhydrogenating activity of the placental enzyme: this enzyme transfers hydrogen from NADP to NAD with recycling of the specific substrate (E1 + E2). For several years the necessary reagents have been commercially available in the form of a kit. Nonetheless, various improvements have been made to the measurement of reduced NAD, which accumulates in the reaction medium and is directly proportional to the concentration of the two estrogens. Three protocols are available at present: Spectrophotometric measurement at 340 nm (initial technique); Colorimetric measurement at 492 nm. The pink colour measured arises from the reduction of a tetrazolium salt (INT) by reduced NAD in a coupled system using diaphorase; Measurement by bioluminescence of the light energy liberated on the reduction of flavin derivatives by NADH. The reaction is mediated by various enzymes isolated from marine bacteria (FMN oxidoreductase and luciferase) in the presence of an aliphatic aldehyde (decanal). The procedure for each of these protocols is described as well as the means for controlling the linearity of the reaction. The choice of protocol is determined by the biological fluid available, the speed of response desired and the cost of the analysis.
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PMID:[Various protocols for determining estrogens by the enzymatic method using estradiol dehydrogenase. Respective procedures and advantages]. 386 35

Wistar male rats were exposed by inhalation to 50, 100 or 400 ppm of ethylene glycol monomethyl ether (EGME) for 1 to 2 weeks. The overall hepatic drug oxidation reactions, O-deethylation of 7-ethoxycoumarin and 7-ethoxyresorufin and cytochrome P-450 content were only slightly affected by the EGME exposures. NADPH cytochrome c reductase activity showed a tendency toward a dose-dependent decrease in liver, the activity being 73% and 64% of that in the controls after one and two weeks of exposure, at 400 ppm respectively. UDP glucuronosyl transferase activity exhibited a dose-dependent enhancement in liver microsomes after exposure for two weeks to EGME. The enhancement was 1.3- 1.7- and 3.0 fold with exposure to 50, 100 and 400 ppm of EGME respectively. After exposure for one week the UDPglucuronosyltransferase activity in kidney microsomes was similarly enhanced. A dose-related increase in measurable UDPglucuronosyltransferase activity was also obtained in Triton X-100 treated hepatic microsomes. GSH levels of the liver and kidneys in EGME treated animals showed a tendency towards a dose-dependent increase. The activities of low-Km and high-Km aldehyde dehydrogenases in liver were decreased 6 - 14% of that in the controls with exposure to 400 ppm of EGME when glycolaldehyde was used as a substrate. Serum alanine aminotransferase activity was not influenced by inhalation exposures to EGME.
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PMID:Dose-dependent toxicity of ethylene glycol monomethyl ether vapour in the rat. 680 Jul 97

The effect of aldehyde fixation on NADPH- and NADH-dependent diaphorase (d) histochemistry and nitric oxide synthase (NOS) immunocytochemistry in the brain was investigated by comparing the distribution of these enzymes in in situ nitrocellulose blots of unfixed brain sections with that in aldehyde-fixed brain sections. Substitution of NADPH by NADH yielded no gross differences in cellular distribution in the native blot, whereas in fixed sections NADH produced nonspecific staining of the entire section. In the in situ blot NADPHd histochemistry therefore visualized general nitroblue tetrazolium reductase (NBTr) activity, which was particularly strong in hippocampal pyramidal neurons and cerebellar Purkinje cells. Aldehyde fixation abolished the anatomical pattern of general NBTr activity and changed the histochemical distribution in that of the NADPHd activity associated with the distribution of NOS-I immunoreactivity (ir). Fixation intensified NADPHd histochem- ical staining in specific neurons, resulting in outstanding, Golgi-like staining of these neurons in several brain regions, whereas the general NBTr activity in pyramidal and Purkinje cells disappeared. In contrast to the histochemical diaphorase distribution, the distribution of NOS-I ir on blots and in aldehyde-fixed brain sections was similar. No NOS was observed in hippocampal pyramidal and cerebellar Purkinje neurons. In regions like cerebral and cerebellar cortex and striatum the applied anti NOS-I serum had a higher affinity for the native protein. It is concluded that aldehydes, rather than to progressively suppress NOS-unrelated enzymes, differentially elicit NADPHd activity in some groups of neurons while leaving NOS-ir unaffected.
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PMID:Aldehyde fixation differentially affects distribution of diaphorase activity but not of nitric oxide synthase immunoreactivity in rat brain. 866 71

The distribution of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase activity was studied in the cichlid fish Tilapia mariae during ontogenesis by the histochemical reaction of NADPH-diaphorase that indicates, in aldehyde-fixed tissue, the presence of nitric oxide synthase, which is the enzyme responsible for nitric oxide production. The first appearance of NADPH-diaphorase-positive neurons has a striking bilateral symmetry and occurs 20 h after fertilization (stage 8) in the olfactory placodes and in the neural tube where two clusters of positive neurons were seen in the diencephalon and in the rhombomere r4 of the hindbrain. Two days after fertilization (stage 10), the clusters of positive neurons showed labeled axons. The two longitudinal fiber bundles that arose from the diencephalic positive neurons ran caudally in the tract of the postoptic commissure. At stage 12 (3.5 days after fertilization), new populations of NADPH-diaphorase-positive neurons appeared in the telencephalon, in some diencephalic nuclei, and in the hypothalamus. Several trigeminal motor neurons showed strong NADPH-diaphorase activity, whereas the optic tectum and cerebellum were completely free of enzymatic activity. In the hindbrain, clusters of positive neurons were seen in the octavolateral region and in the region defined by the exit of the vagus nerve. In the cervical spinal cord, some ventral putative motor neurons were labeled. At stage 14 (5.5 days after fertilization), several periventricular neurons of the optic tectum and some neurons of the cerebellar lamina were labeled. Dorsal neurons, including a few large superficial neurons were also labeled in the cervical spinal cord. NADPH-diaphorase activity was seen in the neuropil area of the telencephalon, the target of olfactory inputs, and in the sensory dorso-lateral area of the spinal cord.
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PMID:Development of NADPH-diaphorase activity in the central nervous system of the cichlid fish, Tilapia mariae. 1055 52

THE ALDEHYDES INTRODUCED IN THIS PAPER AND THE MORE APPROPRIATE CONCENTRATIONS FOR THEIR GENERAL USE AS FIXATIVES ARE: 4 to 6.5 per cent glutaraldehyde, 4 per cent glyoxal, 12.5 per cent hydroxyadipaldehyde, 10 per cent crotonaldehyde, 5 per cent pyruvic aldehyde, 10 per cent acetaldehyde, and 5 per cent methacrolein. These were prepared as cacodylate- or phosphate-buffered solutions (0.1 to 0.2 M, pH 6.5 to 7.6) that, with the exception of glutaraldehyde, contained sucrose (0.22 to 0.55 M). After fixation of from 0.5 hour to 24 hours, the blocks were stored in cold (4 degrees C) buffer (0.1 M) plus sucrose (0.22 M). This material was used for enzyme histochemistry, for electron microscopy (both with and without a second fixation with 1 or 2 per cent osmium tetroxide) after Epon embedding, and for the combination of the two techniques. After fixation in aldehyde, membranous differentiations of the cell were not apparent and the nuclear structure differed from that commonly observed with osmium tetroxide. A postfixation in osmium tetroxide, even after long periods of storage, developed an image that-notable in the case of glutaraldehyde-was largely indistinguishable from that of tissues fixed under optimal conditions with osmium tetroxide alone. Aliesterase, acetylcholinesterase, alkaline phosphatase, acid phosphatase, 5-nucleotidase, adenosine triphosphatase, and DPNH and TPNH diaphorase activities were demonstrable histochemically after most of the fixatives. Cytochrome oxidase, succinic dehydrogenase, and glucose-6-phosphatase were retained after hydroxyaldipaldehyde and, to a lesser extent, after glyoxal fixation. The final product of the activity of several of the above-mentioned enzymes was localized in relation to the fine structure. For this purpose the double fixation procedure was used, selecting in each case the appropriate aldehyde.
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PMID:Cytochemistry and electron microscopy. The preservation of cellular ultrastructure and enzymatic activity by aldehyde fixation. 1397 66

Acetaldehyde is a valuable product of microbial biosynthesis, which can be used by the chemical industry as the entry point for production of various commodity chemicals. In ethanologenic microorganisms, like yeast or the bacterium Zymomonas mobilis, this compound is the immediate metabolic precursor of ethanol. In aerobic cultures of Z. mobilis, it accumulates as a volatile, inhibitory byproduct, due to the withdrawal of reducing equivalents from the alcohol dehydrogenase reaction by respiration. The active respiratory chain of Z. mobilis with its low energy-coupling efficiency is well-suited for regeneration of NAD+ under conditions when acetaldehyde, but not ethanol, is the desired catabolic product. In the present work, we sought to improve the capacity Z. mobilis to synthesize acetaldehyde, based on predictions of a stoichiometric model of its central metabolism developed herein. According to the model analysis, the main objectives in the course of engineering acetaldehyde producer strains were determined to be: (i) reducing ethanol synthesis via reducing the activity of alcohol dehydrogenase (ADH), and (ii) enhancing the respiratory capacity, either by overexpression of the respiratory NADH dehydrogenase (NDH), or by mutation of other components of respiratory metabolism. Several mutants with elevated respiration rate, decreased alcohol dehydrogenase activity, or a combination of both, were obtained. They were extensively characterized by determining their growth rates, product yields, oxygen consumption rates, ADH, and NDH activities, transcription levels of key catabolic genes, as well as concentrations of central metabolites under aerobic culture conditions. Two mutant strains were selected, with acetaldehyde yield close to 70% of the theoretical maximum value, almost twice the previously published yield for Z. mobilis. These strains can serve as a basis for further development of industrial acetaldehyde producers.
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PMID:Improvement of Acetaldehyde Production in Zymomonas mobilis by Engineering of Its Aerobic Metabolism. 3179 41