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

A long-term co-culture of mononuclear cells of human umbilical cord blood with mouse embryo-derived 3T3 fibroblasts resulted in the development of human mast cells. These mast cells are morphologically and functionally mature cells, containing 1.4-2.8 micrograms histamine per 10(6) cells and bear approximately 10(5) Fc epsilon RI per cell. The mast cells sensitized with human IgE released histamine upon challenge with anti-IgE. Electron-microscopic analysis of the cells showed that these cells were mature human mast cells, and clearly different from basophilic granulocytes. Most of the mast cells contained some granules with regular crystalline arrays and both tryptase and chymase, resembling human skin mast cells. When mononuclear cells of cord blood were seeded in a millicell insert which was placed on 3T3 fibroblasts monolayer, the number of mast cells developed in the millicell inserts was comparable to those developed in the co-culture of the same cord blood cells with 3T3 fibroblasts. Recent observations that mast cells developed in the presence of concentrated culture supernatants of 3T3 fibroblasts without fibroblasts feeder layers, confirmed that soluble factors released from 3T3 fibroblasts are essential and sufficient for the differentiation of human mast cell progenitors in vitro. Analysis of functional characteristics of cultured mast cells revealed that they respond to anti-IgE, Ca2+ ionophore A23187 and substance P for histamine release, but failed to respond to compound 48/80 and FMLP. Upon anti-IgE challenge, sensitized mast cells generated approximately 80 ng PGD2 per 10(6) cells, and approximately 50 ng of LTC4 per 10(6) cells but no detectable generation of LTB4.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:In vitro development and functions of human mast cells. 193 64

The characteristics of the acute and late human response to antigen in the upper and lower airways and in the skin is summarized in TABLE 2. This table makes it clear that while mast cells are responsible for the mediator release of the acute phase, eosinophils and basophils are the cells involved in the mediator release which occurs during the experimental late phase reaction. The pattern of mediators observed during the acute response is quite characteristic of the mast cell. Thus, in the nose, skin, and lungs, the acute response is characterized by significant increases in histamine, PGD2, tryptase, and sometimes LTC4. In the late phase reaction, the pattern of mediator release is characteristic of basophils and eosinophils, and includes histamine, LTC4 (where measurable), and eosinophil-derived proteins, without PGD2 or tryptase. Basophils have been identified at appropriate time-points in each model using morphologic and phenotypic criteria, and their numbers relate to the histamine levels. Finally, treatment with glucocorticosteroids, the most potent drugs available for treating chronic allergic inflammation, obliterates the late phase reaction and decreases both mediator release and the infiltration of eosinophils and basophils. Chronic allergic inflammation is now taken by both the pulmonary and immunologic community as a hallmark of asthma, and it can be stated without equivocation that the basophils are responsible for the mediator release observed in that response.
 ...
PMID:The role of basophils in asthma. 195 78

1. Systemic capsaicin treatment of the pig depletes the content of sensory neuropeptides (CGRP and tachykinins) in the airways mucosa and skin, without affecting sympathetic and parasympathetic nerves containing NPY and VIP, or the presence and appearance of inflammatory cells including mast cells. Acute capsaicin exposure caused release of sensory neuropeptides and catecholamines, and marked vasodilation in the airways and skin, without signs of plasma protein extravasation or bronchoconstriction. Capsaicin pretreatment effectively desensitizes against local challenges with capsaicin in the airways and skin, as revealed by the absence of vasodilatory responses 2 days later. 2. Cigarette smoke exposure induces marked vasodilatation, lasting for about 5 min in both the upper and lower airways, which seems not to be primarily caused by particulate matter or nicotine in the smoke. Except for a minor capsaicin-sensitive component in the nasal circulation, these responses probably do not involve neural activation, mast cell degranulation or prostaglandin formation. Rather, it is concluded that vapour phase components act on the vessels via unknown mechanisms. 3. Sensitization of pigs with s.c. injections of ascaris antigen was successful, resulting in typical wheal and flare reactions in the skin and bronchoconstriction after local challenge with antigen. The reactivity to ascaris is probably mediated by antibodies of the IgE isotype. 4. Histamine-containing mast cells and sensory neuropeptide-containing nerve fibers show close morphological association around blood vessels in the pig skin. Both alcian blue-positive mast cells and capsaicin-sensitive sensory nerves are present close to the pig airways epithelium. Sensory neuropeptide-containing nerves are also abundant around airways mucosal blood vessels, whereas the bronchial smooth muscle is sparsely innervated. 5. Allergen and histamine injections in the skin caused similar responses consisting of flare and protein extravasation. Allergen challenge in the airways induces marked vasodilatation lasting for 60-90 min in the pig bronchial and nasal circulations. Histamine seems to be important in the early phase (0-20 min) of these responses in the airways, while cyclooxygenase products (possibly PGD2) may be responsible for the longlasting component. A cyclo-oxygenase product is presumably also released from the lung into the circulation after bronchial allergen challenge and thereby induces a delayed, long-lasting nasal vasodilatation. Histamine may be the main bronchoconstrictor agent released in the immediate allergic reaction of the pig. 6. The flare, but not the protein extravasation reaction, to allergen and histamine injections in the skin, was inhibited by capsaicin pretreatment.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Airways vasodilatation in the immediate allergic reaction. Involvement of inflammatory mediators and sensory nerves. 203 38

Tissue mast cells play a central role in immediate hypersensitivity reactions. The clinical manifestations of these reactions appear to be dependent, in large part, on the anatomic location of the stimulated mast cells and the type of mediators released. In vivo and in vitro studies indicate that the tissues in which mast cells reside may greatly influence their biochemical composition, expression of surface receptors, and response to potential stimuli. Although all human mast cells in different organs store similar concentrations of histamine, heparin, and tryptase, cutaneous mast cells appear to be the predominant source of mast cell-derived chymase. Furthermore, at the time of stimulation, human skin mast cells predominantly form PGD2, whereas lung and intestinal mast cells generate LTB4, LTC4, and PGD2. Functional studies indicate that human cutaneous mast cells differ from human lung, heart, and intestinal mast cells. Skin mast cells are responsive to a variety of immunologic and nonimmunologic stimuli in vitro, whereas human pulmonary, cardiac, and intestinal mast cells are relatively refractory to many of these stimulatory signals. Taken together, these observations indicate that mast cells may assume different, and possibly specialized, functions within a specific tissue. Such site-to-site variation potentially could have important clinical significance, to the extent that information gained from mast cells in one organ may not be applicable to a mast cell population in a different tissue. Furthermore, these differences among human mast cells may not be confined to their biochemical composition and responses to various stimuli, but also may extend to the effectiveness of different anti-allergic preparations. Therefore, these observations underscore the importance of continued detailed investigation of human mast cells from different anatomic sites.
 ...
PMID:IgE and immediate hypersensitivity. 224 56

Exposure of rats to 1-15 Gy of gamma radiation induced hyperthermia, whereas exposure to 20-150 Gy produced hypothermia. Since radiation exposure induced the release of prostaglandins (PGs) and histamine, the role of PGs and histamine in radiation-induced temperature changes was examined. Radiation-induced hyper- and hypothermia were antagonized by pretreatment with indomethacin, a cyclooxygenase inhibitor. Intracerebroventricular administration of PGE2 and PGD2 induced hyper- and hypothermia, respectively. Administration of SC-19220, a specific PGE2 antagonist, attenuated PGE2- and radiation-induced hyperthermia, but it did not antagonize PGD2- or radiation-induced hypothermia. Consistent with an apparent role of histamine in hypothermia, administration of disodium cromoglycate (a mast cell stabilizer), mepyramine (H1-receptor antagonist), or cimetidine (H2-receptor antagonist) attenuated PGD2- and radiation-induced hypothermia. These results suggest that radiation-induced hyperthermia is mediated via PGE2 and that radiation-induced hypothermia is mediated by another PG, possibly PGD2, via histamine.
 ...
PMID:Involvement of prostaglandins and histamine in radiation-induced temperature responses in rats. 230 Jun 72

A cloned murine mast cell line designated MC9 expresses a 5-lipoxygenase activity when stimulated with the ionophore A23187. Upon addition of 0.5 microM ionophore, MC9 cells produce 270 +/- 43 pmoles 5-HETE, 74 +/- 40 pmoles 5,12 diHETEs and 65 +/- 31 pmoles LTC4/10(6) cells from 37 microM exogenously added [1-14C]arachidonic acid in two minutes. 5-HETE and 5,12-diHETES, including LTB4 were identified by GC/MS whereas LTC4 was confirmed by HPLC mobility, bio-assay, RIA and enzymatic transformation. The principal cyclooxygenase products were PGD2 and TxB2 (8.5 +/- 2.4 and 5.4 +/- 1.2 pmoles/10(6) cells respectively). Prostanoids were identified by comigration with authentic standards on two-dimensional thin layer chromatograms. Production of arachidonic acid lipoxygenase metabolites stimulated with ionophore proved relatively insensitive to removal of extracellular Ca+2 and chelation by EGTA. In addition, MC9 5-lipoxygenase required only low micromolar amounts of exogenous arachidonic acid for maximal activity. Whereas production of arachidonic acid metabolites lasted only two to five minutes, histamine release stimulated with ionophore was not initiated until 5 minutes (12 +/- 3% cellular histamine) and continued for 30 minutes (37 +/- 7% cellular histamine). Although these cells metabolize arachidonic acid differently from the classic peritoneal-derived mast cell, they resemble subpopulations found in certain tissues (such as mucosa) and should be useful in understanding the biochemistry of mast cell mediator release.
 ...
PMID:Ionophore-stimulated lipoxygenase activity and histamine release in a cloned murine mast cell, MC9. 240 98

There is now compelling evidence to incriminate bronchial mast cells in the pathogenesis of bronchoconstriction of allergic asthma. Human mast cells isolated from lung tissue or bronchoalveolar lavage release histamine and generate eicosanoids upon IgE-dependent activation. In this paper we present data that raise doubts about the significance of phospholipid methylation in IgE-dependent activation-secretion coupling and provide evidence that drugs such as 3-deazaadenosine inhibit mediator secretion by inhibiting phosphodiesterase, in addition to inhibiting putative methylation pathways. Activation of human mast cells and basophils also stimulates adenylate cyclase to increase levels of cyclic AMP, which, on the basis of pharmacological manipulation with purine nucleosides, we believe is involved in the progression of the secretory response. Human lung cells also generate both cyclo- and lipoxygenase products of arachidonate upon Ca++-dependent stimulation with complex interactions occurring between these pathways in the presence of the leukotriene inhibitor, Piriprost. The role of mast cells in the immediate airway response to inhaled allergens in asthma was demonstrated by showing an interaction between nonspecific bronchial reactivity and mast cell reactivity in predicting the airway response upon antigen inhalation. Further confirmation of this concept was obtained by showing an inverse relationship between the release of histamine and neutrophil chemotactic factor (NCF) into the circulation induced by antigen challenge, and nonspecific airway reactivity. The identification of significant increases in circulating mediators following antigen provocation of patients with seasonal asthma enabled the effects of drugs used in the treatment of asthma to be compared on airway calibre and mast cell mediator release. Sodium cromoglycate partially inhibited the airway and plasma histamine responses with antigen, but totally inhibited the increases in NCF. Salbutamol completely inhibited all responses, while ipratropium bromide, which produced the same bronchoconstriction as achieved with salbutamol, had no effect. The potent H1-antagonist astemizole partially inhibited bronchoconstriction without affecting histamine release. Antigen provocation produced a significant increase in circulating levels of the 13,14-dihydro-15-keto metabolite of PGF2 alpha which could originate from mast cell-derived PGD2. In both retrospective and prospective studies, a close relationship was shown between nonspecific bronchial reactivity and resting airway calibre in asthma.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Relationship between mediator release from human lung mast cells in vitro and in vivo. 240 26

The role of human basophils and mast cells in the pathogenesis of allergic diseases has been analyzed. Purified human basophils and mast cells release several known mediators of allergic reactions, including histamine, sulfidopeptide leukotrienes, kinin-forming enzymes, and, in the case of the mast cell, PGD2. These same mediators are released in vivo after experimental challenge in the upper airways with either allergen or cold, dry air, a stimulus used to simulate exercise-induced bronchospasm. The appearance of mast cell mediators in vivo after such challenges further implicates mast cells in the pathogenesis of allergic diseases of the airways that occur as a result of exposure to allergen or physical stimuli. During the LPR after experimental challenge of the upper airways, the pattern of mediators released (i.e., histamine, leukotrienes, and others, but no PGD2) suggests that basophils may contribute to the LPR. Antiallergic drugs that prevent mediator release in vitro, such as antihistamines, also prevent the appearance of mediators in vivo, strengthening both the validity of the in vitro test as a model of the disease and the hypothesis that mediator release is an essential element of the disease process. A model discussing the pathogenetic mechanism is presented.
 ...
PMID:Role of human basophils and mast cells in the pathogenesis of allergic diseases. 241 Apr 78

Although the mechanism underlying hypoxic pulmonary vasoconstriction remains undefined, various reports have suggested that mast cells and cell-derived mediators may be important in the production of this phenomenon. We investigated the effect of reducing oxygen tension on the release from human lung fragments of the mast cell-derived mediators histamine, prostaglandin (PG) D2 and peptide leukotrienes, as well as the release of the largely non-mast cell-derived mediators PGE2, PGF2 alpha, prostacyclin metabolite (6-keto-PGF1 alpha) and the thromboxane A2 metabolite (thromboxane B2). The effect of reducing oxygen tension on both basal mediator release and release triggered by goat antihuman immunoglobulin E was studied. Reducing pO2 of buffer in which lung fragments were placed from 161 to 54 mm Hg resulted in no spontaneous release of histamine, PGD2 or peptide leukotrienes. However, hypoxia had a marked effect on mediator release triggered by goat antihuman immunoglobulin E. Although net histamine release was relatively unaffected (control 13.9 +/- 2.7%, hypoxic 12.7 +/- 2.1%), hypoxic treatment resulted in an 89% inhibition of PGD2 release (control 47.7 +/- 17.4 ng/g of lung, hypoxic 5.26 +/- 1.91 ng/g of lung) and an 81% inhibition of peptide leukotriene release (control 22.5 +/- 7.6 ng/g of lung, hypoxic 4.37 +/- 2.4 ng/g of lung). Similar inhibition was seen for non-mast cell-derived mediators, including PGF2 alpha, prostacyclin metabolite and thromboxane B2, and probably for PGE2. We conclude that hypoxic treatment of human lung fragments in vitro results in no spontaneous release of preformed or newly formed mediators but that it markedly alters mediator release after goat antihuman immunoglobulin E triggering.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Mediator release from human lung under conditions of reduced oxygen tension. 242 80

Prostaglandin (PG) D2 and histamine concentrations have been measured in blood draining cold-challenged forearm skin in patients with cold urticaria. Local venous concentrations of both histamine and PGD2 rose in four patients who developed a whealing response. Plasma histamine concentration increased from a mean resting value of 0.24 +/- 0.09 (SD) ng/ml to peak values of 16.9 to 96.6 ng/ml. Resting concentrations of PGD2 were below the limit of detection (5 pg/ml) in three patients and 62 and 27 pg/ml in the fourth. Peak plasma PGD2 concentration after challenge ranged from 166 to 279 pg/ml. Time course of histamine and PGD2 release was similar with peak concentrations at 6 and 10 minutes, respectively. The maximum clinical response occurred between 10 and 20 minutes after challenge. Our findings demonstrate that PGD2 is produced in association with mast cell degranulation in man, but the amount, relative to histamine, is low. Despite its high potency in production of inflammatory effects, PGD2 probably has only minor direct effects in cold urticaria, although it may act to potentiate other mediators.
 ...
PMID:Prostaglandin D2 and histamine release in cold urticaria. 242 56


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>