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)

In isolated normal rat jejunum, platelet-activating factor (PAF) induced a dose-dependent increase in short-circuit current (Isc) that was reduced in chloride-free buffer and inhibited by the Cl- channel blocker, diphenylamine-2-carboxylate. An immediate rise in Isc (early phase) occurred that fell to a new elevated base line by 15 min (late phase). These responses to PAF occurred only when experiments were conducted at or before approximately 9 A.M. Early phase responses were blocked by the specific PAF antagonists, BN52021 and WEB2086, and were inhibited by the neurotoxin, tetrodotoxin. Early and late phases were also reduced by cyclooxygenase inhibitors and by doxantrazole, a mast cell stabilizing drug. However, histamine and serotonin antagonists were ineffective. We conclude that PAF causes changes in ion transport that include Cl- secretion and acts on the epithelium possibly via an intermediate cell and enteric nerves. In addition, known PAF receptors are involved in one component of the response that appears to follow a circadian rhythm.
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PMID:Effects of platelet-activating factor on ion transport in isolated rat jejunum. 259 84

The role of the immune system in controlling intestinal electrolyte transport was studied in rat and rabbit colon in Ussing chambers. A phagocyte stimulus, the chemotactic peptide FMLP, and a mast cell stimulus, sheep anti-rat IgE, caused a brief (less than 10 min) increase in short-circuit current (Isc). Products of immune system activation, platelet-activating factor (PAF) and reactive oxygen species (ROS), caused a sustained, biphasic increase in the Isc. Ion replacement and flux studies indicated that these agonists stimulated electrogenic Cl secretion and inhibited neutral NaCl absorption; responses that were variably inhibited by the cyclooxygenase blockers indomethacin and piroxicam. Lesser degrees of inhibition by nordihydroguaiaretic acid could be accounted for by decreased prostaglandin synthesis rather than by lipoxygenase blockade. Tetrodotoxin, hexamethonium, and atropine also inhibited immune agonist-stimulated Isc, but had no effect on immune agonist-stimulated production of PGE2 or PGI2. These results indicate that immune system agonists alter intestinal epithelial electrolyte transport through release of cyclooxygenase products from cells in the lamina propria with at least 50% of the response being due to cyclooxygenase product activation of the enteric nervous system. The immune system, like the enteric nervous system and the endocrine system, may be a major regulating system for intestinal water and electrolyte transport in health and disease.
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PMID:Immune system control of rat and rabbit colonic electrolyte transport. Role of prostaglandins and enteric nervous system. 272 60

Injection of zymosan in rat pleural cavity provokes an exudate which is already detectable at 15 min and which is maximum at 24 h. The leucocyte count (mostly neutrophils) increases at 2-4 h and is maximum at 48 h. In this paper the reaction has been studied up to 6 h. Evidence of histamine release, of mast cell degranulation and of reduction of the exudate by anti-H1 compounds, as well as by sodium cromoglycate, proves the active role played by histamine in the early stage of pleurisy. Serotonin (whose role was studied exclusively using antagonists) seems to have only a minor part in the early phase of the reaction. Some metabolites of arachidonic acid were determined in the pleural exudate at 1 h and 6 h. The concentration of leukotriene B4 was high at 1 h and decreased at 6 h. The thromboxane B2 level was already high at 1 h and was neatly augmented at 6 h while the amount of prostaglandin F1 alpha was high at both times. The non-steroidal anti-inflammatory substances studied all reduced the pleural exudate at 1 h but their activity then varied from each other at 6 h. Cyclooxygenase and lipoxygenase inhibitors (phenidone, BW755C) induced a reduction of the exudate at both times. Zymosan-induced pleurisy seemed thus to be an excellent model for the investigation of antiallergic and anti-inflammatory compounds active on histamine and cyclooxygenase and lipoxygenase pathways.
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PMID:Pharmacological studies on zymosan inflammation in rats and mice. 2: Zymosan-induced pleurisy in rats. 277 57

Antigen challenge of ovalbumin (OA)-sensitized guinea pigs results in significant (p less than 0.05) increases in vascular permeability to Evans blue (EB) dye in the airways, esophagus, and bladder. Mean values +/- SEM in ng EB/mg wet weight tissue for unsensitized versus sensitized animals were: trachea, 23.6 +/- 6.6 versus 92.5 +/- 11.1; main bronchi, 31.1 +/- 12.2 versus 153.1 +/- 14.9; "central" intrapulmonary airways (ipa), 34.6 +/- 11.2 versus 101.3 +/- 6.2; and "peripheral" ipa, 26.2 +/- 6.8 versus 93.5 +/- 13.6. We investigated the involvement of several mediators of inflammation in this process. FPL 55712, a sulfidopeptide leukotriene receptor antagonist, caused significant inhibition of leakage in trachea (to 55.1 +/- 9.8) and main bronchi (91.7 +/- 15.8). Blockade of the cyclooxygenase and lipoxygenase pathways with BW 755C, but not of the cyclooxygenase pathway alone with indomethacin, also significantly reduced EB dye extravasation in trachea (55.1 +/- 18.0), main bronchi (71.7 +/- 23.0), and "central" ipa (62.7 +/- 16.4). The histamine antagonists, chlorpheniramine and cimetidine, only inhibited microvascular leakage in main bronchi (94.4 +/- 20.0). PAF-receptor blockade with the ginkgolide mixture BN 52063 had no effect. Nedocromil sodium, a mast cell stabilizer and an inhibitor of inflammatory cell activation, caused significant inhibition throughout the airways: trachea, 50.4 +/- 10.6; main bronchi, 72.0 +/- 15.3; "central" ipa 61.0 +/- 8.6; "peripheral" ipa 41.9 +/- 12.2. Thus, histamine and lipoxygenase products (in particular, leukotrienes), but not PAF, may mediate the antigen-induced increase in vascular permeability to different degrees in differing regions of the respiratory tract in guinea pigs.
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PMID:Inflammatory mediators involved in antigen-induced airway microvascular leakage in guinea pigs. 284 29

We examined the interaction between mast cell-derived mediators and the electrical and ion transport properties of canine tracheal epithelium. We compared the effect of mediators released by immunologic challenge of sensitized lung parenchyma with that of mediators released from canine mastocytoma cells challenged with calcium ionophore A23187. Short-circuit current (Isc) increased by 19.2 +/- 3.0 microA/cm2 in response to mediators released from sensitized lung fragments challenged with ragweed antigen. This effect was not due to histamine. When the epithelial tissues were pretreated with indomethacin, the same mediator supernatant increased Isc by only 3.8 +/- 4.3 microA/cm2. The mediators released from 10(7) mastocytoma cells challenged with calcium ionophore increased Isc by 25.1 +/- 13.6 microA/cm2. In the presence of indomethacin, the Isc increased by 2.0 +/- 0.4 microA/cm2. Mastocytoma-derived mediators produced an increase in net chloride secretion without a significant effect on net sodium absorption. This study provides direct evidence that mast cell-derived mediators can stimulate epithelial ion transport in canine trachea and suggests that the effect is indirect and dependent on intact cyclooxygenase pathways in the tracheal epithelium.
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PMID:Effects of mast cell-derived mediators on epithelial cells in canine trachea. 309 76

In order to assess the role of arachidonic acid metabolites in the early reaction to antigen, we challenged six allergic individuals with and without premedication with aspirin and recorded their clinical response, as indicated by number of sneezes, and measured the levels of inflammatory mediators. The early reaction to antigen was associated with increases in the levels of histamine, N-alpha-tosyl-L-arginine methyl esterase (TAME-esterase) activity, prostaglandin (PG) D2, leukotriene C4, PGE, and thromboxane. Aspirin significantly inhibited the increases in the cyclooxygenase metabolites PGE, PGD2, PGF2 alpha, 6-keto-PGF1 alpha, and thromboxane but did not affect the amount of sneezing or the levels of histamine, TAME-esterase activity, or leukotrienes. The pattern of the metabolites and their response to pretreatment with aspirin parallel the response of purified human lung mast cells, supporting the notion that the early phase of allergic rhinitis is a mast cell-dominated event.
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PMID:Arachidonic acid metabolites during nasal challenge. 309 12

Treatment for 24 h in vitro with dexamethasone inhibited the antigen-induced contractile response in guinea pig tracheal rings and parenchymal strips without inhibiting the contractile response of the tissues to either methacholine or histamine, respectively. Antigen-induced histamine release was inhibited by approximately 50% in both tissues by prior treatment with dexamethasone. Dexamethasone treatment also inhibited the release of immunoreactive sulfidopeptide leukotriene from parenchymal strips. In tracheal rings, dexamethasone treatment reduced spontaneous release of all cyclooxygenase metabolites (PGE2, PGF2 alpha, TXB2, PGD2, and 6-k-PGF1 alpha were tested), with the exception of PGD2, and also inhibited the antigen-induced release of all cyclooxygenase metabolites studied. Dexamethasone-treatment did not inhibit the spontaneous release of cyclooxygenase metabolites in the guinea pig lung strips, and only modestly inhibited the antigen-induced release of PGE2, PGF2 alpha, and PGD2. The results suggest that the inhibition of contractile response of guinea pig lung strips and airway tissue to antigen by dexamethasone is the result of a reduced release of inflammatory mediators. The inhibition by dexamethasone of antigen-induced release of mast cell mediators from guinea pig lung parenchyma contrasts with results previously obtained with human parenchymal lung tissue.
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PMID:Dexamethasone inhibits the antigen-induced contractile activity and release of inflammatory mediators in isolated guinea pig lung tissue. 310 4

Exposure to ethanol in man has been linked to an alteration of the immune surveillance system and reduced ability of the macrophage to undergo phagocytosis. Since ethanol has been suggested to alter membrane function and inhibit the production of calcium ionophore stimulated synthesis of prostaglandins and leukotrienes by the human neutrophil and transformed murine mast cell, the dose response effect of ethanol on the biosynthesis of icosanoids by the peritoneal macrophage during zymosan phagocytosis was studied. Peritoneal macrophages from two inbred strains of mice derived from a common stock (HS) and selected for sensitivity to ethanol (short sleep [SS]/long sleep [LS]) were studied. Zymosan phagocytosis was found to lead to synthesis of LTC4 (70 ng/10(6) cells), 6-keto-PGF1 alpha (5 ng/10(6) cells) and PGE2 (3 ng/10(6) cells). For the HS macrophage, ethanol caused a dose dependent inhibition of these lipid mediators as well as inhibition of phagocytosis and release of beta-hexosaminidase. However, a difference was observed in arachidonate metabolism stimulated by phagocytosis between the LS and SS mice below 100 mM ethanol. The SS mouse had a 50% inhibition of cyclooxygenase products at 86 mM ethanol with no inhibition of lipoxygenase metabolites. The LS mice had a trend suggesting increased lipoxygenase metabolites below 100 mM ethanol. At these levels of ethanol which can be found in man, these results suggest there may be differential production of lipid mediators under genetic control.
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PMID:The effect of ethanol on arachidonic acid metabolism in the murine peritoneal macrophage. 311 Aug 61

Inflammatory reactions induced by TPA (12-O-tetradecanoylphorbol 13-acetate)-type tumor promoters, including TPA, teleocidin and aplysiatoxin, and chemical mediators responsible for such inflammatory reactions were analyzed. The tumor promoter dissolved in a 0.8% sodium carboxymethyl cellulose solution was injected into a subcutaneous air pouch preformed on the dorsum of rats. Within 30 min after the injection, vascular permeability as measured by the leakage of labeled albumin into the pouch fluid was increased, with a concomitant increase in histamine level. This increase in vascular permeability was inhibited by a histamine antagonist, pyrilamine, and a serotonin antagonist, methysergide. Vascular permeability at 4 h was not inhibited by pyrilamine or methysergide but was inhibited by a cyclooxygenase inhibitor, indomethacin, with a parallel decrease in the prostaglandin E2 level in the pouch fluid. These results suggest that the TPA-type tumor promoters induce inflammation by the mechanism of mast cell degranulation within a short period, this being followed by the stimulation of arachidonic acid metabolism. The mechanism of the in vivo effect of the TPA-type tumor promoters is discussed and compared with in vitro effects that we have previously reported.
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PMID:Analysis of tumor-promoter-induced inflammation in rats: participation of histamine and prostaglandin E2. 311 92

Arachidonic acid (AA) injected into hindpaws of Lewis rats produces a severe edematous response. Treatment with corticosteroids (dexamethasone, prednisolone), dual inhibitors of arachidonate metabolism (phenidone, SK & F 86002), anti-histamine/serotonin agents (chlorpheniramine, cyproheptadine) and a gold compound (auranofin) inhibited AA-induced edema. In contrast, administration of high doses of cyclooxygenase inhibitors (indomethacin, piroxicam, naproxen, ibuprofen, meclofenamic acid and tiflamizole) did not affect AA-induced hind paw edema. The involvement of lipoxygenase products and mast cell mediators in the edematous response to arachidonic acid render this model potentially useful for studying antiinflammatory agents with a mechanism of action different from that of cyclooxygenase inhibitors.
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PMID:The pharmacology of arachidonic acid-induced rat paw edema. 312 May 9


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