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:1.6.5.2 (NQO1)
6,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In vitro alterations induced by a 10 micrograms/ml and 50 micrograms/ml dose each of thiophenate and fenbendazole on the absorptive surfaces of Haemonchus contortus (Nematoda: Trichostrongylidae) were studied. The most significant changes were induced in the gut epithelium. Alkaline phosphatase and adenosine triphosphatase activities were decreased, succinic dehydrogenase activity was increased, while acid phosphatase and glucose-6-phosphatase were completely lost from the intestinal epithelium after treatment with either of the drugs. A stimulatory effect of these two anthelmintics was observe on lactic dehydrogenase and reduced nicotinamide adenine dinucleotide diaphorase distribution. Thiophenate caused an increase in the activities of glutamate dehydrogenase (GDH), glucose-6-phosphate dehydrogenase (G-6-PD) and nonspecific esterases and a decrease in reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-D) activity. Fenbendazole treatment led to the inhibition of GDH, while G-6-PD, NADPH-D, cytochrome oxidase, monoamine oxidase and nonspecific esterase activity remained unaltered in the epithelium.
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PMID:Histoenzymic effects of thiophenate and fenbendazole on the absorptive surfaces of Haemonchus contortus. 133 82

Serotoninergic and cholinergic neurons are known to appear earlier in the ontogeny (day E12) of the murine gut than those containing substance P or vasoactive intestinal peptide (day E14). It has also been demonstrated that proliferating neural precursors coexist with mature neurons in developing enteric ganglia. These observations have led to the hypotheses that peptidergic neurons develop later than those that utilize small molecule neurotransmitters and that the activity of early developing neurons may affect the phenotypic expression of coexisting neuroblasts. As a partial test of these hypotheses we studied the phenotypic expression of neurons recognized by antisera to neuropeptide Y (NPY) and calcitonin gene-related peptide (CGRP), and of those visualized by the histochemical demonstration of reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase activity. NADPH diaphorase activity, which is coexpressed with NPY immunoreactivity in all submucosal and many myenteric neurons, was first found on day E11 in clusters of cells in the dorsal mesogastrium. These cells also expressed neurofilament reactivity and thus were developing along a neuronal lineage. Enteric neurons that expressed NADPH diaphorase activity were visualized in the stomach one day later, on day E12. At this time, NADPH diaphorase-containing cells could no longer be demonstrated in the dorsal mesogastrium. NPY immunoreactivity first appeared in the wall of the bowel on day E12, when it was seen in cells in the presumptive stomach. By day E13, the entire length of the bowel contained NPY-immunoreactive neurons. Cells that displayed NADPH diaphorase activity were found at this time at both ends of the alimentary tract, but did not appear in the ileum until day E18. In contrast, CGRP immunoreactivity could not be detected anywhere in the gut until day E17, but by day E18 all regions of the bowel contained CGRP-immunoreactive neurons. Endogenous 5-HT was first detected at day E16 in mucosal epithelial cells in all segments of the gut except the stomach, where it appeared at day E18. The NPY/NADPH diaphorase set of neurons thus develop before the acquisition of a detectable level of endogenous 5-HT or enteric neural 5-HT receptors (which arise in the foregut at day E14). These observations demonstrate that enteric neurons that express small molecule neurotransmitters do not necessarily develop earlier than peptidergic neurons as a class; however, various types of enteric neurons do appear in a sequential order.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Time course of expression of neuropeptide Y, calcitonin gene-related peptide, and NADPH diaphorase activity in neurons of the developing murine bowel and the appearance of 5-hydroxytryptamine in mucosal enterochromaffin cells. 278 79

A histological and histochemical study of ingested food material, energy stores and enzymes in the monogenean Pseudodactylogyrus anguillae, parasitizing the gills of the European eel (Anguilla anguilla) is presented. It was found that mucus, epithelial cells and blood from the gills were ingested. Glycogen deposits were small and primarily located in the parenchyma and to a minor extent in the vitellariae. Numerous globules of neutral lipids were found in the vitellariae. A marked esterase activity was found in the gut and a less marked activity in the vitellariae. Acid phosphatase activity was found throughout the body whereas alkaline phosphatase and leucine-amino-peptidase were not detected. Marked activity of succinate dehydrogenase and NADH-diaphorase was found in all cells, indicating a predominantly aerobic metabolism in this monogenean.
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PMID:The nutrition of the gill parasitic monogenean Pseudodactylogyrus anguillae. 342 77

The number of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d)-positive cells in the myenteric plexus increased 1 week after surgical extrinsic denervation of a loop of guinea pig ileum. NADPH-d staining in submucosal ganglia and vasoactive intestinal polypeptide immunoreactivity in submucosal and myenteric ganglia were not affected by denervation. Similar data were obtained after systemic capsaicin, but not 6-hydroxy-dopamine treatment, suggesting that loss of primary afferents increases NADPH-d staining. Increases in NADPH-d may be part of an adaptive process allowing normal gut function after loss of extrinsic nerves.
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PMID:Extrinsic denervation increases NADPH diaphorase staining in myenteric nerves of guinea pig ileum. 751 42

Nitric oxide has been put forward as an important inhibitory neurotransmitter in the gut. Nitric oxide synthase-containing neurons were visualized by immunocytochemistry using antibodies against neuronal nitric oxide synthase or by beta-nicotinamide adenine dinucleotide phosphate diaphorase staining in whole mounts and cryostat sections from the gastrointestinal tract and pancreas of several mammals (mouse, rat, hamster, guinea-pig, cat and man). Nitric oxide synthase-containing neuronal cell bodies were numerous in the myenteric but fewer in the submucous ganglia all along the gut of all species. Varicose nerve terminals formed extensive networks in the circular smooth muscle and the myenteric ganglia. Nitric oxide synthase-containing nerve terminals were frequently found around the Brunner glands in the duodenum; scattered nerve terminals were also found in the gastric and colonic mucosa and around blood vessels in the submucosa all along the gut. In the rat small and large intestine nitric oxide synthase-containing submucous neurons terminated within the mucosa/submucosa and nitric oxide synthase-containing myenteric neurons issued short descending projections, approximately 3 mm, to the smooth muscle and other myenteric ganglia. In the pancreas of all species nitric oxide synthase-containing nerve cell bodies were regularly seen in intrapancreatic ganglia. Positive nerve fibers were mainly found within nerve trunks in interlobular spaces and as delicate fibers within the islets. Double staining for nitric oxide synthase and neuropeptides in intestine and pancreas of rat, guinea-pig and man revealed that only occasionally the nitric oxide synthase-containing nerve cell bodies stored in addition vasoactive intestinal peptide and neuropeptide Y, or enkephalin. However, nitric oxide synthase-containing nerve terminals, particularly those in the circular muscle of the gut, frequently contained vasoactive intestinal peptide/neuropeptide Y (rat and man) or vasoactive intestinal peptide/enkephalin (guinea-pig). In intrapancreatic ganglia few nitric oxide synthase-containing nerve cell bodies were also vasoactive intestinal peptide-immunoreactive. Coexistence of nitric oxide synthase and vasoactive intestinal peptide in nerve terminals could here be detected around blood vessels and interlobular ducts. The distribution of nitric oxide synthase indicates a major role of nitric oxide in the regulation of gut motility; a role in the regulation of blood flow and secretion in both gut and pancreas is also likely.
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PMID:Distribution, origin and projections of nitric oxide synthase-containing neurons in gut and pancreas. 753 82

The localization of reduced nicotinamide adenine dinucleotide phosphate diaphorase in the submucous plexus of duodenum, jejunum, ileum, proximal colon, distal colon and rectum in the guinea-pig was examined histochemically by light and electron microscopy. The majority of reactive submucous neurons displayed features common to either Dogiel type I or type II neurons; some were closely adherent to the outer walls of lymphatic vessels. The use of 2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl) tetrazolium chloride (BSPT) at the ultrastructural level showed that nicotinamide adenine dinucleotide phosphate diaphorase is a membrane-associated protein widely distributed in the cells, including the rough endoplasmic reticulum, Golgi apparatus and synaptic vesicles in the axon terminals associated with submucous neurons. On the basis of their diaphorase reactivity or the lack of it, the submucous neuronal somata and their associated terminals were observed to form several different kinds of synaptic configurations. The present quantitative analysis showed that the frequency of reactive submucous neurons in the large intestine was significantly higher than in the small intestine. Based on the ultrastructural localization of the diaphorase reaction product in positive cells, it is speculated that nitric oxide might be synthesized within the neurons. The demonstration of different synaptic configurations in the submucous ganglia suggests that the functional interaction between submucous neurons is extremely complex. Finally, the higher frequency of diaphorase reactive submucous neurons in the large intestine than in the small intestine indicates that submucous neurons in these two gut regions may not play equivalent roles.
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PMID:Localization of NADPH-diaphorase activity in the submucous plexus of the guinea-pig intestine: light and electron microscopic studies. 764 33

The localization of nitric oxide synthase, the enzyme responsible for producing the short-acting messenger nitric oxide, has been determined in the digestive tract of the rat using histochemistry for reduced nicotinamide adenine dinucleotide phosphate-diaphorase activity, a specific marker for neuronal nitric oxide synthase. Positively stained neurons were found throughout the entire digestive tract from the esophagus to the rectum. Positive neuronal somata were very common in the myenteric ganglia. Dense positive fibers were distributed in internodal strands, the secondary plexus, the tertiary plexus, and were particularly abundant in the deep muscular plexus, while very few were observed in the submucosal ganglia. The density of these positive structures was higher in the small and large intestine than in the esophagus and stomach. The pattern of distribution suggested that some of these positive cells innervate gut muscles. Double-staining revealed that in these enteric neurons, nitric oxide synthase does not co-localize with acetylcholinesterase. Instead, vasoactive intestinal polypeptide almost always coexists with nitric oxide synthase in the myenteric plexus. Thus, nitric oxide and vasoactive intestinal polypeptide may be co-transmitters in a population of non-adrenergic, non-cholinergic neurons in the enteric nervous system.
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PMID:Histochemical localization of nitric oxide synthase in rat enteric nervous system. 768 13

The ultrastructural organization and some histochemical characteristics of the enteric nervous system (ENS) were investigated in 10- and 18-week-old human fetuses. In the 10-week-old human fetus immature myoblasts, and mostly neuroblasts were found in the ganglia. Simple, undifferentiated neuropil was observed among neuronal cells. The neuropil generally did not contain synapses; however axosomatic synapse was registered rarely on the surface of certain neurons. Neuromuscular junctions were common, both axons and neurons were in close contact with the sarcolemma. In the 18-week-old human fetus the fine-structural characteristics of the intestinal smooth muscle cells were the same as in the adult. Nerve profiles were frequently found among the muscle cells. NADH-diaphorase histochemistry revealed the presence of numerous ganglia but solitary neurons still occurred. Differentiated neurons and neuroblasts could be distinguished in the myenteric ganglia. Synapses were often detected in the neuropil. Thick nerve plexuses were frequently found in the proximity of smooth muscle cells, forming "distant" and "close" myoneural contacts. Well-defined fluorescent network and several fluorescent nerve cell bodies were demonstrated by glyoxylic acid. The above organization may provide a satisfactory basis for an integrated peristaltic movement in the gut of the 18-week-old human fetus.
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PMID:Ultrastructure of the developing muscle and enteric nervous system in the small intestine of human fetus. 819 75

Biochemical studies have shown that the NADPH-diaphorase (NADPH-d) activity of nitric oxide synthase (NOS) represents only a part of the total cellular diaphorase pool. Histochemically, NADPH-d activity can be demonstrated in cells expressing no constitutive NOS. Therefore, attempts aimed to improve the specificity of the NADPH-d reaction are currently being undertaken. In this study, the effect of replacing the natural and common diaphorase substrate beta-NADPH with the artificial stereoisomer alpha-NADPH on the extent of NADPH-d staining was examined. When beta-NADPH served as the substrate, discrete populations of central and peripheral neurons as well as numerous non-neural cells in many organs of common laboratory rodents (mouse, rat, gerbil, hamster, guinea pig) and marmosets were found to generate formazan. Substitution of alpha-NADPH for beta-NADPH resulted in reduced staining intensity of nerve cells and muscle fibers. Furthermore, alpha-NADPH-d staining of macula densa cells, enterocytes and granulocytes varied according to the species examined. No reaction was observed in most other cells which stained positively for beta-NADPH-d activity. Examination of adjacent sections, incubated for the demonstration of NOS-immunoreactivity, revealed that alpha-NADPH-d activity and NOS immunostaining are strictly colocalized in neurons, striated muscle fibers and, species-dependently, in macula densa cells. It can thus be concluded that, with the exception of gut granulocytes, alpha-NADPH is primarily metabolized by the reductase activity of NOS.
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PMID:Alpha-NADPH appears to be primarily oxidized by the NADPH-diaphorase activity of nitric oxide synthase (NOS). 852 90

Classically, development of the human enteric nervous system has been characterized by the early appearance (between 9 and 12 weeks' gestation) of adrenergic and cholinergic nerves. The development of peptidergic innervation occurs much later. Recent studies have indicated that nitric oxide is involved in the nonadrenergic noncholinergic innervation of the gut, mediating its relaxation. The authors have investigated the ontogeny of nitrergic (nitric oxide synthase-containing) neurons of the developing gut. Bowel segments from the esophagus, pylorus, and ileocecal and rectosigmoid regions of 14 fetuses (gestational age range, 12 to 23 weeks) were studied with nicotinamide adenosine dinucleotide phosphate (NADPH) diaphorase histochemistry. By 12 weeks' gestation, nitrergic neurons had appeared in the myenteric ganglia, at all levels of the gut, and had begun plexus formation. Nitrergic innervation in the submucous plexus becomes evident after 14 weeks. As gestational age increases, nitrergic innervation becomes richer and more organized. Increasing numbers of nitrergic nerve fibers are seen in the circular muscle; some of these fibers project from the myenteric plexus. By 23 weeks' gestation, nitrergic innervation has matured to the pattern observed in the postnatal gut. Thus, the onset and pace of development of nitrergic innervation are similar to adrenergic and cholinergic innervation and occur before peptidergic innervation. This study provides morphological evidence of the ontogenetic significance of nitrergic innervation in the human gut and supports previous suggestions that nitric oxide has a pathophysiological role in developmental gut motility disorders.
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PMID:Nitrergic innervation of the human gut during early fetal development. 886 76


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