Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Opioids differ in their capacity to cause release of histamine. The effects of increasing concentrations of three opioids (morphine, buprenorphine, and fentanyl) were studied on the release of preformed (histamine and tryptase) and de novo synthesized (prostaglandin D2 [PGD2] and peptide-leukotriene C4 [LTC4]) chemical mediators from human peripheral blood basophils and mast cells isolated from skin tissues or lung parenchyma. Basophils released < 5% of their histamine content and did not synthesize significant amounts of LTC4 when incubated with any of the opioids. Mast cells showed markedly different responses to the three opioids. Morphine (10(-5)-3 x 10(-4) M), in a concentration-dependent manner, induced histamine and tryptase release from skin but not from lung mast cells, up to a maximum of 18.2 +/- 1.9% and 13.0 +/- 4.1 micrograms/10(7) cells, respectively. Morphine did not induce de novo synthesis of PGD2 from skin mast cells. Buprenorphine (10(-6)-10(-4) M), in a concentration-dependent manner, caused histamine and tryptase release from lung but not from skin mast cells, to a maximum of 47.6 +/- 7.2% and 35.1 +/- 13.6 micrograms/10(7) cells, respectively. Buprenorphine also induced de novo synthesis of PGD2 and LTC4 from lung mast cells. Fentanyl (10(-5)-10(-3) M) did not induce histamine and tryptase release or the de novo synthesis of PGD2 or LTC4 from any mast cells. Histamine release caused by buprenorphine from lung mast cells was slow (t1/2 = 11.2 +/- 3.6 min) compared with that induced by morphine from skin mast cells (t1/2 < 1 min, P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Human basophil/mast cell releasability. IX. Heterogeneity of the effects of opioids on mediator release. 128 14

Pathophysiologic mechanisms of perennial rhinitis are poorly understood. The characterization of inflammation was studied in nasal lavage of patients with perennial rhinitis by the enumeration of cells involved in the allergic inflammation and the measurement of six mediators released in nasal secretions to determine whether some mediators were relevant for the etiologic diagnosis and the occurrence of symptoms. Ten healthy subjects and 57 patients with perennial rhinitis were placed into four groups according to the symptoms they presented at the time of the study and the origin of the allergy. Allergy was characterized by the history, skin prick tests to standardized allergens, and RAST. Eosinophil protein X (EPX), tryptase, histamine, myeloperoxidase, prostaglandin D2, and leukotriene C4/D4 (LTC4/D4) were measured in nasal lavage by enzyme assay or radioimmunoassay. Eosinophils and neutrophils were enumerated after cytocentrifugation of the lavage fluid and May Grunwald Giemsa staining. Tryptase, myeloperoxidase and EPX but not histamine levels were increased in all four patient groups. Eosinophils, LTC4/D4, and prostaglandin D2 were significantly (p < 0.001, p < 0.03, and p < 0.01) increased in allergic and symptomatic patients. EPX was significantly increased in symptomatic allergic and nonallergic patients. This study suggests the involvement of mast cells, neutrophils, and eosinophils, but the latter cells appear to have a more prominent role. The importance of EPX and LTC4/D4 in the characterization of chronic symptomatic rhinitis was also observed.
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PMID:Indirect evidence of nasal inflammation assessed by titration of inflammatory mediators and enumeration of cells in nasal secretions of patients with chronic rhinitis. 133 2

Segmental antigen bronchoprovocation was used to define the nature of the inflammatory process in allergic airway disease. Bronchoalveolar lavage fluid obtained from allergic rhinitis patients 12 min after segmental antigen instillation (immediate response) revealed a significant increase in histamine and tryptase, but no cellular response. Repeat segmental lavage 48 h later (late response) showed marked and significant increases in both low and normal density eosinophils as well as striking elevations of eosinophil granular protein levels (major basic protein, eosinophil-derived neurotoxin, eosinophil cationic protein, and eosinophil peroxidase). Leukotriene C4, but not tryptase, concentrations were also consistently elevated in late lavage samples. Further, the late lavage samples showed a significant increase in interleukin-5 concentrations that correlated with the presence of eosinophils and eosinophil granular proteins. Neither eosinophils nor soluble mediators of eosinophils increased when normal subjects were similarly challenged with antigen. These data suggest that eosinophils are attracted to the airway during the late-phase allergic reaction and that IL-5 may produce changes in airway eosinophil density and promote the release of granular proteins to cause airway injury.
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PMID:Immediate and late airway response of allergic rhinitis patients to segmental antigen challenge. Characterization of eosinophil and mast cell mediators. 174 38

Mast cells and basophils, although sharing many constitutive properties, are quite distinct in their development, functions and biological properties. Mast cell granules are composed of a macromolecular matrix of proteoglycan and neutral protease of which heparin and tryptase, respectively, are predominant. The distribution of the other major neutral protease, chymase, allows human mast cell subpopulations to be subdivided immunocytochemically. All human mast cells respond to IgE-dependent stimulation with the secretion of the preformed mediator, histamine, and the newly generated lipid-derived eicosanoids PGD2 and LTC4. Although amounts of these products vary between mast cells dispersed from different tissues, it is uncertain whether this reflects true heterogeneity. Mast cells of the human skin, but not those of other tissues, are sensitive to stimulation by substance P, compound 48/80 and other basic non-immunological stimuli. The mechanism of mediator secretion induced by these agents is distinct from that induced by IgE-dependent stimulation. However, the morphological characteristics of degranulation are similar, suggesting that the distinct biochemical pathways merge into a common pathway before effecting degranulation.
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PMID:Biological properties of human skin mast cells. 191 78

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)
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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.
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PMID:The role of basophils in asthma. 195 78

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.
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PMID:IgE and immediate hypersensitivity. 224 56

Mast cells and macrophages were isolated from human lung tissues by using density gradient centrifugation, cell sorter, and adherence techniques. Passively sensitized mast cells in the absence of exogenous arachidonic acid (AA) released leukotriene (LT)C4, LTD4, PGD2, and thromboxane-B2 when challenged with Ag, and in the presence of AA, released 5-hydroxyeicosatetraenoic acid (HETE) and 15-HETE in addition to the above metabolites. Passively sensitized macrophages did not release significant amounts of AA metabolites when challenged with Ag. However, these cells released LTB4, LTC4, LTD4, LTE4, 5-HETE, PGE2 and 6-keto-PGF1 alpha when co-incubated with activated mast cells. During co-incubation, mast cells also generated greater amount of AA metabolites than when they were activated alone. The stimulatory action of mast cells on macrophages was shown to be due to the extracellular factor(s) present in the supernatant of the activated mast cells. Both heat and trypsin inhibited the biologic activity of mast cell-derived stimulatory factor. In addition, extraction of mast cells' materials with chloroform or ether showed no activity associated with the organic phase, suggesting it possibly possesses a protein nature, such as peptides, protease, or peptidase. These results suggest that mast cell-macrophage interaction might be important in the generation of multiple mediators in the airways during immediate hypersensitivity reactions.
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PMID:Mast cell mediators stimulate synthesis of arachidonic acid metabolites in macrophages. 249 26

Confluent hamster tracheal surface epithelial (HTSE) cells in primary culture are enriched with secretory cells that synthesize and release mucins. Using this cell culture system, we investigated possible mechanisms of goblet cell mucin release by altering the media bathing the apical surface of HTSE cells: medium hyperosmolarity decreased mucin release, whereas hypo-osmolarity increased release without causing a cytoplasmic leak due to plasma membrane damage. A Ca2+ ionophore, A23187, did not influence mucin release. Both acidic (pH less than 4) and basic (pH greater than 9) media caused significant increases in mucin release secondary to cell membrane damage. Physiologic concentrations of chemical mediators such as prostaglandins (PGE2 and PGF2 alpha) and leukotrienes (LTC4 and LTD4) did not influence mucin release. Both elastase and cathepsin G derived from human neutrophils caused marked increases in release, whereas trypsin from the porcine pancreas produced a small increase only at a high concentration. We conclude that mucin release by cultured airway goblet cells can be enhanced by: (1) irritant gases, (2) luminal fluid osmolarity, (3) pharmacologic concentrations of LTC4 and LTD4, and (4) cationic proteases, each presumably acting by different mechanisms. Each of these mechanisms may play a role in epithelial mucin secretion associated with airway inflammation.
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PMID:Mechanisms of airway goblet cell mucin release: studies with cultured tracheal surface epithelial cells. 269 48

Although a great deal has been learned about the mediators produced by mast cells, the ultimate biologic function(s) of mast cell remains a mystery. Histamine, LTC4, PAF, and possibly tryptase (C3a generation) all enhance vasopermeability. Mediators with anticoagulant activities such as heparin and tryptase (fibrinogenolysis) and antithrombotic activity, PGD2, would appear to facilitate dispersion in tissues of the plasma ultrafiltrate brought there by the subgroup of mediators that enhance vasopermeability. In contrast, PAF causes platelet aggregation and chymase may cause arteriolar vasoconstriction (decreasing the volume of plasma reaching venules) by generation of angiotensin II. Assessment of any differential production of mediators by different types of mast cells will be of obvious importance in sorting out the physiologic responses to mast cell activation as well as the pathophysiology of allergic reactions.
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PMID:Mediators of human mast cells and human mast cell subsets. 310 66


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