Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasma extravasation responses to silver nitrate (AgNO3), histamine, 5-hydroxytryptamine (5-HT), bradykinin and prostaglandin E1 (PGE1) in the abdominal skin, hindpaw ankle joint and subplantar region of rats have been investigated using the Evans blue dye leakage technique. All substances tested produced plasma extravasation and combination of low doses (5 x 10(-10) mol) of either histamine or bradykinin with PGE1 (5 x 10(-10) mol) exhibited potentiation of responses of all regions. Responses to AgNO3 (1 x 10(-6) mol) were significantly reduced by the H1 receptor antagonist, mepyramine, only in the abdominal skin, but the H2 receptor antagonist metiamide reduced the responses at subplantar and ankle joint regions. Indomethacin significantly reduced the AgNO3 responses at the ankle joint only, but aprotinin reduced it at the other two regions. In rats pretreated with a combination of all antagonists the residual plasma extravasation response to AgNO3 was very small, indicating that the response could be almost totally accounted for by the combined actions of mast cell amines, kinins and prostanoids. The finding that prostanoids played a major role in the plasma extravasation response of the rat ankle joint to AgNO3 indicated that this model would be useful for the screening of non-steroidal anti-inflammatory drugs.
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PMID:Mediators of the plasma extravasation response to silver nitrate in the rat skin, subplantar region and ankle joint. 256 64

Nitric oxide (NO.) plays a central role in the physiology of the gastrointestinal tract and its response to critical illness. Potential sources of NO. in the gut include: intrinsic intestinal tissue (mast cells, epithelium, smooth muscle, neural plexus), resident and/or infiltrating leukocytes (neutrophils, monocytes), reduction of luminal gastric nitrate, and denitrification by commensal anaerobes. The brain and endothelial isoforms of nitric oxide synthase are expressed under resting conditions, whereas inflammatory stimuli are required for the induction of the inducible type. Under resting conditions, mucosal perfusion is regulated by NO. derived from the vascular endothelium of the mesenteric bed. During inflammation, excessive NO. production from the inducible synthase may contribute to mucosal hyperemia. Coordination of peristalsis and sphincteric action is mediated by the release of NO., which acts as the principal neurotransmitter of the nonadrenergic, noncholinergic enteric nervous system. Alterations in bowel motility, such as ileus, result from excessive concentrations of NO. generated during endotoxicosis and inflammatory bowel disease. The role of NO. in the regulation of salt and water secretion is poorly understood. Endotoxin-induced inhibition of gastric acid secretion appears to be mediated by the action of NO. on parietal cells. NO. may protect the gastrointestinal mucosa from a variety of stimuli (caustic ingestion, ischemia, ischemia/reperfusion injury, early endotoxic shock) by maintaining mucosal perfusion, inhibiting neutrophil adhesion to mesenteric endothelium, blocking platelet adhesion, and preventing mast cell activation. Excessive NO., however, may directly injure the mucosa. Barrier function of the intestinal mucosa is protected by NO. in the early stages of injury, when neutrophil adhesion, ischemia, and mast cell activation are relevant. Inhibition of NO. synthesis ameliorates barrier dysfunction during more advanced stages of inflammation, when activation of inducible NOS yields toxic concentrations of NO.. At high concentrations, NO. disrupts the actin cytoskeleton, inhibits ATP formation, dilates cellular tight junctions, and produces a hyperpermeable state. Selective inhibition of the inducible isoform of NOS and maintenance of the constitutive types may be therapeutic.
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PMID:Nitric oxide in the gut. 758 76

To evaluate the relationship between atmospheric nitrogen dioxide exposure and the development of allergic diseases, the effects of nitrite as a chemical product of inhaled nitrogen dioxide on mast cell functions were investigated. We have studied nitrite-induced histamine release from two functionally distinct mast cell populations, namely peritoneal mast cells (PMC) and intestinal mucosal mast cells (IMMC) of Nippostrongylus brasiliensis-infected rats. High concentrations of nitrite alone (10, 20, and 50 mM) induced histamine release from IMMC, but not from PMC. Moreover, histamine release from PMC and IMMC stimulated with sensitizing antigen was significantly enhanced by pretreatment with 50 mM nitrite or nitrate. No differences in histamine release from nitrite-treated and control PMC were seen below 1 mM. To investigate the effect of nitrite on tumor cell cytotoxic activity, PMC were incubated with various concentrations of nitrite. Pretreatment with 5 and 50 mM nitrite markedly depressed tumor necrosis factor (TNF)-alpha-dependent natural cytotoxicity of PMC for the tumor target WEHI-164. Thus, high concentrations of nitrite enhanced mast cell histamine release, but depressed TNF-alpha-dependent cytotoxicity. However, low concentrations of nitrite (< 1 mM) that would normally be produced by short-term atmospheric exposure to nitrogen dioxide may have no significant effects on mast cell functions.
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PMID:Further studies on the effect of nitrogen dioxide on mast cells: the effect of the metabolite, nitrite. 768 33

Nitric oxide (NO.) plays a central role in the Physioliology of the gastrointestinal tract and its response to critical illness. Potential sources of NO. in the gut include: intrinsic intestinal tissue (mast cells, epithelium, smooth muscle, neural plexus), resident and/or infiltrating leukocytes (neutrophils, monocytes), reduction of luminal gastric nitrate, and denitrification by commensal anaerobes. The brain and endothelial isoforms of nitric oxide synthase are expressed under resting conditions, whereas inflammatory stimuli are required for the induction of the inducible type. Under resting conditions, mucosal perfusion is regulated by NO. derived from the vascular endothelium of the mesenteric bed. During inflammation, excessive NO. production from the inducible synthase may contribute to mucosal hyperemia. Coordination of peristalsis and sphincteric action is mediated by the release of NO., which acts as the principal neurotransmitter of the nonadrenergic, noncholinergic enteric nervous system. Alterations in bowel motility, such as ileus, result from excessive concentrations of NO. generated during endotoxicosis and inflammatory bowel disease. The role of NO. in the regulation of salt and water secretion is poorly understood. Endotoxin-induced inhibition of gastric acid secretion appears to be mediated by the action of NO. on parietal cells. NO. may protect the gastrointestinal mucosa from a variety of stimuli (caustic ingestion, ischemia, ischemia/reperfusion injury, early endotoxic shock) by maintaining mucosal perfusion, inhibiting neutrophil adhesion to mesenteric endothelium, blocking platelet adhesion, and preventing mast cell activation. Excessive NO., however, may directly injure the mucosa. Barrier function of the intestinal mucosa is protected by NO. in the early stages of injury, when neutrophil adhesion, ischemia, and mast cell activation are relevant. Inhibition of NO. synthesis ameliorates barrier dysfunction during more advanced stages of inflammation, when activation of inducible NOS yields toxic concentrations of NO.. At high concentrations, NO. disrupts the actin cytoskeleton, inhibits ATP formation, dilates cellular tight junctions, and produces a hyperpermeable state. Selective inhibition of the inducible isoform of NOS and maintenance of the constitutive types may be therapeutic.
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PMID:Nitric oxide in the gut. 770 93

Leukocyte-endothelial cell adhesion and an altered metabolism of endothelial cell-derived nitric oxide (NO) have been implicated in the microvascular dysfunction associated with ischemia/reperfusion (I/R). The objective of this study was to determine whether NO donors can attenuate the reperfusion-induced increase in venular albumin leakage via an effect on leukocyte-endothelial cell adhesion. Leukocyte adherence and emigration as well as albumin extravasation were monitored in single postcapillary venules in rat mesentery subjected to 20 minutes of ischemia followed by 30 minutes of reperfusion. This I/R protocol elicits significant leukocyte adherence and emigration as well as a profound albumin leakage response. Superfusion of the mesenteric microcirculation with the NO donors sodium nitroprusside, spermine-NO, and SIN1 significantly reduced the I/R-induced leukocyte adherence/emigration and albumin leakage in postcapillary venules, whereas neither spermine nor the NO synthase inhibitor NG-nitro-L-arginine methyl ester affected the I/R-induced responses. Platelet-leukocyte aggregation and mast cell degranulation were also observed in the postischemic mesentery, and the responses were also attenuated by the NO donors. Plasma nitrate/nitrite levels in the superior mesenteric vein were significantly reduced by I/R. The results of this study indicate that I/R-induced microvascular dysfunction (albumin leakage) is attenuated by NO and that the protective effect of NO donors may be related to their ability to reduce leukocyte-endothelial cell and leukocyte-platelet interactions and/or mast cell degranulation.
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PMID:Modulation of ischemia/reperfusion-induced microvascular dysfunction by nitric oxide. 811 46

Exposure of sensitized individuals to antigen can induce allergic responses in the respiratory tract, manifested by early and late phases of vasodilatation, plasma leakage, leukocyte influx, and bronchoconstriction. Similar responses can occur in the skin, eye, and gastrointestinal tract. The early-phase response involves mast cell mediators and the late-phase response is leukocyte dependent, but the mechanism of leakage is not understood. We sought to identify the leaky blood vessels, to determine whether these vessels contained endothelial gaps, and to analyze the relationship of the gaps to adherent leukocytes, using biotinylated lectins or silver nitrate to stain the cells in situ and Monastral blue as a tracer to quantify plasma leakage. Most of the leakage occurred in postcapillary venules (< 40-microns diameter), whereas most of the leukocyte migration (predominantly neutrophils) occurred in collecting venules. Capillaries and arterioles did not leak. Endothelial gaps were found in the leaky venules, both by silver nitrate staining and by scanning electron microscopy, and 94% of the gaps were distinct from sites of leukocyte adhesion or migration. We conclude that endothelial gaps contribute to both early and late phases of plasma leakage induced by antigen, but most leakage occurs upstream to sites of leukocyte adhesion.
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PMID:Endothelial gaps and adherent leukocytes in allergen-induced early- and late-phase plasma leakage in rat airways. 962 51

Synthetic nitric oxide donors are known to protect the gastric mucosa from damage and dietary nitrate is known to release NO in the stomach. Mast cells have been found to be involved in gastric mucosal damage in humans or in rodents, and recent studies have pointed out the possibility of nitric oxide from endogenous or exogenous origin to modulate mast cell reactivity. This study aimed to determine whether the protective effect afforded by dietary nitrate against gastric mucosal damage was linked to mast cell stabilization. Mast cell involvement in iodoacetamide-induced gastritis was investigated in rats receiving oral administration of iodoacetamide together with the mast cell stabilizer doxantrazole (ip) or its solvent. The effects of dietary nitrate on mast cells during gastritis were investigated in rats receiving iodoacetamide orally, associated or not with KNO3. Control groups were given water instead of iodoacetamide either with or without KNO3, doxantrazole or its solvent. After sacrifice, blood samples were taken to determine RMCP II serum level and the stomach was resected in order to determine myeloperoxidase (MPO) activity and mucosal mast cell (MMC) number. Iodoacetamide significantly increased gastric MPO activity but did not modify RMCP II serum level or MMC number. Doxantrazole and KNO3 significantly reduced iodoacetamide-induced increase in gastric MPO activity, increased MMC number, and decreased RMCP II serum level in basal conditions. Only doxantrazole was able to modify all parameters under inflammatory conditions. These results suggest that nitric oxide released by dietary nitrate in the stomach stabilizes mast cells in basal conditions but exerts its protective effect against experimental gastritis through other pathways.
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PMID:Effect of dietary nitric oxide on gastric mucosal mast cells in absence or presence of an experimental gastritis in rats. 1286 90

The possible role of mast cell in neutrophil migration failure during sepsis was examined in a polymicrobial sepsis model in mice. Mast cells were depleted by compound 48/80 or lysed by distilled water, both preventing the neutrophil migration failure. This phenomenon was accompanied by reduction of bacteria in the peritoneal cavity and blood, serum tumor necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta) and nitrate (NO3) and by an increase in mice survival rate. Neither neutrophil migration failure nor significant mortality was observed when lethal inoculum was injected into the air-pouch model, a cavity poorly populated by mast cells. Confirming that neutrophil migration failure is a phenomenon induced by systemic circulating mediators, it was observed that i.p. administration of lethal inoculum induced a neutrophil migration failure to the air pouch inoculated with non-lethal bacterial challenge. These results suggest that mast cells have a key role in the genesis of neutrophil migration failure, and, consequently, contribute to the systemic inflammatory response and mortality in severe sepsis.
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PMID:Effect of mast cells depletion on the failure of neutrophil migration during sepsis. 1626 1

Mice experimentally infected with H. nana and injected with immunosuppressant {cyclophosphamide (Cp) and lead nitrate (Ln)} showed significant increase in infection intensity, significant decrease in intestinal mast cell count, dissemination of larvae to the liver, toxic hepatitis and absence of specific serum IgG. Cyclophosphamide caused morphological abnormallities in adult worms, prolongation of patent period and more severe villous changes. Immuno-stimulants represented by Levamisol (Lv) and gamma interferon (IFN-alpha) caused significant decrease in infection intensity, significant shortening of patent period and early improvement of histopathological changes. Immunostimulants, particularly IFN-alpha, were highly effective in counteracting hyperinfection seen with immuno-suppression. The study confirmed the deleterious effects of immunosuppression on hymenolepiasis and suggested a beneficial role for immunotherapy for immunosuppressed patients.
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PMID:Effect of some immunomodulators on the host-parasite system in experimental Hymenolepiasis nana. 1660 1

Antiallergic activity of Aristolochia bracteolata was evaluated by using compound 48/80 induced anaphylaxis, dermatitis rhinitis and pruritus, as a preclinical model for acute phase of hypersensitivity reactions. The late phase hypersensitivity was evidenced by considering toluidine diisocyanate induced volume of bronchoalveolar fluid secretion and its inhibition. The possible antiallergic mechanism was evaluated by using compound 48/80 induced mast cell activation and estimated serum nitric oxide (NO), rat peritoneal fluid NO, bronchoalveolar fluid NO and blood histamine levels. The present study implied that the chloroform extract of Aristolochia bracteolata had potent and significant inhibitory effect on compound 48/80 induced pruritus and dermatitis activity in Swiss albino mice. It showed significant effect in toluidine diisocyanate induced rhinitis in swiss albino mice. Mast cell membrane stabilization activity was also observed in compound 48/80 induced mast cell activation. A significant reduction was observed in serum nitrate levels, rat peritoneal fluid nitrate levels and BAL nitrate levels. The extract was also found to possess significant inhibitory effect on blood histamine levels. It could be concluded that chloroform extract of A. bracteata possess potent antiallergic activity, possibly through mast cell membrane stabilization, inhibiting NO and histamine pathway.
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PMID:Antiallergic activity of Aristolochia bracteolata Lank in animal model. 2035 66


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