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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It had been reported by authors that salivary gland hormone, parotin, was composed with subunit (parotin-subunit) which showed molecular weight of 45,000, and that parotin-subunit had rabbit serum calcium decreasing activity and the cross reactivity with rabbit anti parotin serum. In the present report, in order to study physiological chemistry of parotin-subunit, the influence of parotin-subunit on serum Ca and 45Ca levels relating to calcium metabolism, the distribution of 131I-parotin-subunit, the effect of parotin-subunit, on adenyl cyclase-cyclicAMP system, the anabolic action, C-terminal amino acid sequence and sugar component of parotin-subunit were investigated. The results are summarized as follows: 1) The decrease of rabbit serum Ca after injection of parotin-subunit was related to change of Ca in stable bone, but not to inhibition of bone resorption. 2) A high concentrated localization of radioactivity of 131I-parotin-subunit was found in liver, kidney and spleen, and as much as 60% of administrated radioactivity was localized in liver at 5 min after the injection. The retention of radioactivity was found in testis, seminal vesicle, prostate, parotid gland and submaxillary gland. 3) Cyclic AMP level increased significantly in metaphysial bone, submaxillary gland and plasma after administration of parotin-subunit but in other organs with localized much radioactivities, the level did not changed. Parotin-subunit activated adenyl cyclase of particular fraction of metaphysial bone. 4) The C-terminal amino acid of parotin-subunit was Leu, and its C-terminal amino acid sequence was -Val-Ser-Ala-Thr- Leu-OH by digestion of carboxypeptidase A. 5) Parotin-subunit included 3.3% of sugar which consisted of amino sugar and uronic acid.
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PMID:[The study of physiological chemistry on a subunit of salivary gland hormone (2) (author's transl)]. 18 2

"Immunopharmacology" evolved as a field of research in its own right when it was appreciated that pharmacological methods can contribute to the understanding of immune mechanisms on the one hand or can be used to influence or even control immune reactions at all stages and levels. The best studied subjects of immunopharmacology are release and effects of the chemical mediator substances which are responsible for the reactions of effector cells thus causing the clinical symptoms in allergic or inflammatory diseases. In the type I allergic (anaphylactic) reactions the primary target cells are tissue mast cells or basophil granulocytes which discharge their granular contents upon interaction of immunoglobulin E fixed to their surface with the specific antigen or--in the anaphylactoid reaction--upon stimulation with an appropriate chemical substance (so-called histamine-liberator). In both cases the stimulus leads to an influx or intracellular shift from one compartment to another of calcium ions, which in turn trigger membrane fusion and degranulation. This process can vary from a physiological secretion (in the case of IgE-antigen-interaction) to a pathological cytolysis (in the case of high concentrations of activated complement components or other chemical histamine releasers). As long as it is secretory it is subject to vegetative and hormonal modulation and regulation, mainly by catecholamines and other substances which increase cellular cAMP levels or inhibit calcium fluxes. Although cholinergic stimuli under certain circumstances induce mast cell degranulation and histamine release no definite role has yet been established for cholinergic mechanisms in type I allergies. Type II (Cytotoxic) and type III (immune complex mediated) allergies share the complement requirement. As far as mast cells and basophils are involved in such reactions their sensitivity towards pharmacological modulators is comparable to reactions induced by chemical histamine releasers. Otherwise these types of allergic reactions are dominated by phenomena of general inflammation. In those mainly cytotoxic effects of lipases and hydrolases are involved. cAMP active agents have, therefore, only limited modulating effects and steroid hormones are more effective in inhibiting the acute lesions in type II and III allergies. Only during the last decade the involvement of chemical mediators in type IV (cellular immunity) allergic reactions has been appreciated. 26 different factors called lymphokines have been discovered and classified as mediators of cellular immune reactions. However, rather little is yet known about their chemical nature and about the influence of drugs on their production or action.
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PMID:Pharmacological aspects of immune reactions. 36 29

The activation of mast cells (MC) due to immunological stimulation causes an immediate and dramatic inflammatory response. We review current evidence indicating that the membrane permeabilities for calcium, chloride, sodium, and potassium have a significant role in the activation of these cells, and in some cases, specific ionic channels have been identified. Moreover, a number of intracellular mechanisms controlling these channels are pointed out, including different classes of G proteins, intracellular calcium, cAMP, and products of phosphoinositol breakdown. However, the interplay between factors controlling membrane conductances for different ions is not currently understood. The diversity of ionic effects on MC activation is depicted, illustrating that the ionic mechanisms of MC activation are specific for different MC types. Since nerve/mast cell interaction is a key element in the burgeoning field of neuroimmunology, we discuss the role of ionic channels as targets of neurotransmitter action in MC activation.
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PMID:Mast cell ionic channels: significance for stimulus-secretion coupling. 137 80

The isolation and kinetics of survival of human mast cells from newborn and adult skin is described. Recombinant human interleukins and conditioned medium from several human cell lines were tested for their ability to maintain mast cells in vitro. Growth medium supplemented with IL-2, IL-4 and conditioned medium from a mixed lymphocyte culture enhanced mast cell survival resulting in a 30-fold increase in survival (relative to that obtained with non-supplemented medium) at 7 days, and a 15-fold increase at 15 days. Cell survival for time periods longer than 21 days was not observed. Inclusion of cAMP, agents that elevate cAMP, insulin, and epidermal growth factor in supplemented growth medium prevented the enhanced survival by 40-70%. Incorporation of bromodeoxyuridine (BrdU) into mast cells in 3-day cultures demonstrated that 15% of the mast cell population was capable of proliferation. At 21 days, no incorporation of BrdU could be detected. After 3 days in culture mast cells released 16% of their histamine stores in response to A23187 and 10% in response to anti-human IgE. Electron microscopy of cultured cells at 3 days revealed cells with both intact and empty mast cell granules. These results demonstrate that human skin mast cells proliferate in response to cytokines and release histamine when stimulated with classical secretagogues. Since human skin mast cells retain these basic properties in vitro, they may be useful in further functional studies involving their proliferation and secretion.
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PMID:Factors affecting the growth and maintenance of human skin mast cells in cell culture. 138 46

1. Guinea pig parenchymal lung strips and tracheal smooth muscle contract potently after NaF-addition. Maximal contractions of lung strips and tracheal rings induced by NaF were 208 +/- 17% (n = 6) and 151 +/- 8% (n = 4) of the maximal histamine response respectively. 2. The -log EC50-value for NaF on lung strips and tracheal rings was 2.38 +/- 0.01 (n = 6) and 2.28 +/- 0.01 (n = 4) respectively. 3. Contractions induced by NaF were augmented after Al3+ pretreatment, suggesting the involvement of a G-protein. NaF responses were not affected by blockade of H1-, muscarinic-, leukotriene C4- or leukotriene D4-receptors, indicating that mast cell degranulation or nerve activation is most probably not implicated. 4. Contractions after NaF-addition were relatively insensitive to removal of extracellular calcium and were reversed via cAMP- and cGMP-mediated pathways. 5. Relaxation studies with (-)isoprenaline and 8-bromo-cGMP on lung strips, precontracted to similar levels with either a H1-agonist, KCl or NaF, showed that the level of relaxation depends on the contractile agent that is used. 6. After precontraction with KCl (-)isoprenaline relaxes lung strips only to 58 +/- 9% (n = 5) of the initial contraction, whereas lung strips precontracted with NaF or a H1-agonist relax 114 +/- 8% (n = 4) and 120 +/- 7% (n = 5) respectively with (-)isoprenaline. 7. Similar results were obtained with relaxation induced with 8-bromo-cGMP. 8. These findings suggest that NaF-induced contractions are elicited via a mechanism, that is probably similar to that of the H1-receptor. The involvement of a G-protein in the observed NaF-responses is therefore likely.
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PMID:Fluoride is a contractile agent of guinea pig airway smooth muscle. 165 87

A mouse spleen-derived mast cell line (PT-18) was employed to examine the mechanisms of adenosine 3':5'-monophosphate (cAMP)-mediated inhibition of antigen-induced lipid mediator biosynthesis. Specifically, we tested the hypothesis that increasing cAMP in mast cells inhibits lipid mediator biosynthesis by a mechanism independent of effects on histamine release (degranulation) or changes in cytosolic calcium concentration. Forskolin inhibited antigen-induced prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and leukotriene B4 (LTB4) production by 30-50%. In contrast, forskolin had no inhibitory effect on antigen-induced increases in cytosolic calcium concentration, as monitored by the calcium indicator fura-2, or histamine release from the cells. The combination of the phosphodiesterase inhibitor isobutylmethylxanthine with forskolin inhibited the antigen-induced production of PGD2 and LTC4 by 90-100% and histamine release by about 60%. These responses were accompanied by a virtual abolition of the antigen-induced increase in cytosolic calcium. To test further the hypothesis that increasing cAMP can lead to inhibition of lipid mediator biosynthesis in the absence of effects on cytosolic calcium, we employed the calcium ionophores A23187 and ionomycin. Forskolin alone or in combination with isobutylmethylxanthine had no effect on ionophore-induced increases in cytosolic calcium but effectively inhibited leukotriene biosynthesis. In addition, increasing cyclic AMP led to an inhibition of ionophore-induced production of platelet-activating factor and liberation of arachidonic acid. These data suggest that a relatively modest increase in cAMP-dependent protein kinase activity in mast cells leads to inhibition of the lipase-catalyzed cleavage of arachidonic acid from membrane phospholipids in the absence of measurable effects on either histamine release or changes in cytosolic calcium concentration. This effect results in a selective inhibition of the biosynthesis of lipid mediators including LTC4, LTB4, PGD2, and platelet-activating factor.
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PMID:Inhibition by adenosine 3':5'-monophosphate of eicosanoid and platelet-activating factor biosynthesis in the mouse PT-18 mast cell. 169 Nov 75

Rat serosal mast cells were evaluated for their capacity to generate a nitric oxide-like factor by two bioassays: inhibition of platelet aggregation and stimulation of mast cell guanylate cyclase. Incubation of mast cells with human washed platelets, both treated with indomethacin, inhibited thrombin-induced platelet aggregation which was potentiated by superoxide dismutase and reversed by oxyhaemoglobin. When mast cells alone were stirred at 1000 rpm, a time dependent increase in the levels of their cGMP but not cAMP was observed. Preincubation of mast cells with NG-monomethyl-L-arginine significantly enhanced E. coli lipopolysaccharide-evoked histamine release. Our results show that mast cell histamine release can be modulated by an intrinsically generated nitric oxide-like factor.
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PMID:Rat mast cells synthesize a nitric oxide like-factor which modulates the release of histamine. 171 38

An increase in inositol 1, 4, 5-trisphosphate (IP3) formation in rat mast cells precedes an elevation in intracellular Ca2+ levels, which triggers the process(es) leading to histamine release. By means of a transmission electron microscope, it was revealed that when permeabilized mast cells were exposed to potassium antimonate, antimonate precipitates in the endoplasmic reticulum (ER) in the form of calcium antimonate, indicating that the ER is the intracellular Ca store in rat mast cells. IP3 at concentrations higher than 0.5 microM preferentially releases Ca2+ from the isolated ER of mast cells. GTP was also effective in releasing Ca2+ from the ER. IP3-induced Ca2+ release was inhibited by pretreatments with cAMP and antiallergic drugs. An increase in the intracellular Ca2+ concentration may lead to an activation of calmodulin, C kinase and cytoskeletal elements in sequence. Furthermore, microtubules may play an important role in the process(es) leading to Ca2+ release from the intracellular Ca store and subsequent histamine release, without affecting IP3 formation. In contrast, microfilaments seem to participate not only in the extrusion but also in the reincorporation of the mast cell granules, having no influence on intracellular Ca2+ release. Substance P (SP) is one of the most effective neuropeptides for releasing histamine from mast cells. Structure-activity relationship studies indicate that basicity at the N-terminal and hydrophobicity at the C-terminal are requisite for its histamine releasing activity. SP effectively released Ca2+ from the intracellular Ca store. The site of action of SP on the mast cell surface seems to be the same as that of compound 48/80. Eosinophil major basic protein (MBP) and histone are also effective for releasing histamine. The cDNA sequences of two subclasses of guinea pig MBP have been determined. These proteins may be released at the site of inflammation from the cells activated by the chemical mediators released from mast cells, and consequently, mast cell activation was reinforced. Such cell-to-cell interaction may be the reason for the augmentation of inflammation.
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PMID:[Recent advances in the research on histamine release]. 172 Jul 58

Rat serosal mast cells were tested for their ability to generate a nitric oxide-like factor by two bioassay systems: inhibition of platelet aggregation and stimulation of mast cell guanylate cyclase. Incubation of rat serosal mast cells with human washed platelets resulted in an inhibition of thrombin-induced platelet aggregation proportional to the number of cells. The inhibition was potentiated by superoxide dismutase (SOD) and reversed by oxyhaemoglobin (oxyHb). The inhibitory activity of mast cells was also prevented by NG-monomethyl-L-arginine (MeArg), an effect reversed by co-incubation with L-Arg but not D-Arg. When mast cells alone were stirred at 1,000 rpm, a time-dependent increase in the levels of their cGMP but not cAMP was observed. This increase was reduced by pretreatment with MeArg. The inhibitory effect of MeArg was reversed by L-Arg but not D-Arg. These results demonstrate that rat mast cells release a factor with the same pharmacological profile as NO, and that this NO-like factor is derived from L-arginine.
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PMID:Synthesis of a nitric oxide-like factor from L-arginine by rat serosal mast cells: stimulation of guanylate cyclase and inhibition of platelet aggregation. 197 20

We have reported that mast cells adhere to laminin after activation with PMA. In this study, we demonstrate that the cross-linking of cell surface high-affinity IgE-R on mast cells derived from mouse bone marrow cultured for 3 wk in the presence of WEHI-3-conditioned media acts as a highly sensitive physiologic stimulus for this attachment and that receptor activation is also induced by calcium ionophore A23187. Adherence occurred at threefold log concentrations less of A23187 and Ag than required for histamine release in a selective subpopulation comprising 20 to 30% of the total cells. At higher concentrations of agonist that permitted histamine release, the time course for degranulation was shown to be more rapid than that of adherence. Adherence was inhibited by antibodies to laminin and laminin receptor and was calcium ion and temperature dependent. Treatment of cells with dibutyryl cAMP, which activates protein kinase A, inhibited both adherence and histamine release induced by Ag or calcium ionophore. Treatment of cells with staurosporin, which inhibits protein kinase C, also inhibited adherence and histamine release induced by calcium ionophore, but was not significantly active against either adherence or histamine release induced by Ag. It thus appears that agents which modulate intracellular signaling mechanisms are equally effective toward histamine release and adherence, suggesting these two events are intimately linked in stimulus secretion coupling. Specific cytokines stimulating mast cell adhesion to laminin could not be found; however, culture of mast cells with TGF-beta 1 was determined to enhance IgE-mediated adherence to laminin. Hence, the high-affinity IgE-R on the mast cell functions not only in exocytosis but also facilitates the process of mast cell adherence to laminin.
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PMID:Regulation of adhesion of mouse bone marrow-derived mast cells to laminin. 214 20


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