Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.31 (beta-glucuronidase)
7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This review demonstrates that basophils reflect skin and lung mast cell reactivity and show characteristic changes in mediator release associated with clinical disease. Although the numbers of IgE molecules and IgE receptors on basophils have been enumerated, these have, in most instances, little influence on the release of histamine after challenge. There is, rather, a parameter of "releasability" that may be a major variable in allergic disease states. Basophils contain and release histamine, the eosinophil chemotactic factor of anaphylaxis (ECFA), a slow reacting substance of anaphylaxis (SRS-A), and a kallikrein. The release process is controlled by hormone-basophil receptor interactions that determine the cyclic AMP level; plasma and tissue adenosine levels appear prominent in this control. Histamine feeds back to negatively modulate basophil and mast cell release through a specific histamine 2-receptor; it also inhibits lymphocyte and neutrophil function. Like neutrophils, basophils contain beta-glucuronidase while neutrophils contain SRS-A and a low-molecular-weight ECF. The stimuli for primary basophil and neutrophil release are, however, quite different, although phagocytic stimuli, which fail to cause basophil mediator release, potentiate the IgE response. It is concluded that basophols play a significant in vivo role in inflammation by acting as an interface between foreign antigens, the serum cascade systems, and other inflammatory cells.
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PMID:The role of basophils in inflammatory reactions. 7 20

Many clinical abnormalities in atopic eczema have been attributed to an imbalance in autonomic nervous system control, specifically a partial blockade of beta-adrenergic responsiveness. The lysosomal enzyme beta-glucuronidase is released from granulocytes during in vitro incubation with complement-activated zymosan particles. Isoproterenol will inhibit the release of this lysosomal enzyme from the granulocyte and the isoproterenol effect is associated with increased granulocyte cyclic AMP formation. In atopic eczema and asthma, this granulocyte response to isoproterenol is impaired. Histamine also inhibits in vitro zymosan induced release of beta-glucuronidase and this is an H2 histamine effect. In asthma, this H2 histamine response is diminished. In the following study, we found a similar impairment in histamine inhibition of beta-glucuronidase release and formation of granulocyte cAMP in atopic eczema. This defect was found only in granulocytes from patients with active eczema. Thus in active atopic eczema, defects in the pharmacological response of the granulocyte are not limited to beta-adrenergic agonists but include H2 histamine activity.
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PMID:Impaired H2 histamine granulocyte response in active atopic eczema. 22 50

The effects of histamine on lung macrophages have been studied by both biologic and radioligand experiments. After overnight adherence, lung macrophages spontaneously released beta-glucuronidase (beta-G) at a rate of approximately 7 nmol of hydrolyzed substrate/h/million cells. Histamine at low concentrations (10(-9) to 10(-8) M) resulted in a consistent potentiation of this release. The concentration-effect curve of histamine was bell-shaped, reaching an optimum at 10(-9) M, with concentrations greater than 10(-8) M having no significant effect. At a maximally effective concentration (10(-9) M), histamine evoked a 135 +/- 9.6% (mean +/- SE; n = 8, P less than 0.001) potentiation in the total amount of beta-G released during the first 60 min of incubation. This increase in beta-G release represented both a slight increase in beta-G synthesis as well as an increase in the percentage of beta-G released. When the secreted beta-G is expressed as a percentage of total content, histamine (10(-9) M) evoked a 125 +/- 3.2% (mean +/- SE; n = 27, P less than 0.0005) enhancement. The potentiation of beta-G release by histamine was evident after 45 min of incubation and persisted for up to 6 h. The potentiation of beta-G by histamine was sensitive to inhibition by pyrilamine (10(-7) M).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Histamine acting on a histamine type 1 (H1) receptor increases beta-glucuronidase release from human lung macrophages. 225 84

A summarizing survey of different studies in atopic eczema involving three types of cells (platelets, neutrophils, basophils) and their mediators is given. Platelets were found to release normal amounts of serotonin upon stimulation with epinephrine, thrombin and slightly reduced amounts after aggregated IgG stimulation. Serotonin uptake by washed platelets was found to be slower in atopics than in normals. Neutrophils showed a decreased release of beta-glucuronidase to stimuli like zymosan or aggregated IgG in atopics compared to controls. This might be regarded as a contributory factor to the well-known decreased resistance to infections observed in atopic eczema. Basophils in most studies released increased amounts of histamine in the atopic population compared to controls, especially after stimulation with anti-IgE. Concomitantly to the histamine release there was a slight increase in prostaglandin E2 production both in atopics and normals, which was increased by preincubation with reduced glutathion-a coenzyme of PGE2 isomerase. Histamine release tended to occur faster in atopics. Two possible factors influencing releasability characteristics were studied, namely the cyclic nucleotide system and arachidonic acid (AA) dependent mechanisms. Leucocytes of atopics showed a decreased response of cAMP to beta-adrenergic and an increased response of cGMP to cholinergic stimulation. Significant augmentation of anti-IgE-induced histamine release was observed after cholinergic stimulation. AA metabolites obviously play a regulating role in mediator release. PGE2 inhibited histamine release to various stimuli both in atopics and in normals. Indomethacin enhanced histamine release, especially after anti-IgE stimulation in atopics, while it inhibited complement-dependent release reactions both in atopics and in normals. The exogenous inhibitors of lipoxygenase eicosatetraynoic acid (ETYA) and nordihydroguaretic acid (NDGA) inhibited histamine release equally in atopics and normals. The endogenous lipoxygenase inhibitor 15-HETE showed no inhibitory but rather a slight enhancing effect upon histamine release. It is concluded that patients with atopic eczema often exhibit altered releasability patterns to a variety of stimuli. On the basis of our findings we describe "altered releasability" as one factor of a vicious cycle between increased IgE-production, mediator secretion and T cell regulatory disturbances in the pathogenesis of atopic eczema.
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PMID:Altered releasability of vasoactive mediator secreting cells in atopic eczema. 240 33

Platelets, basophils and neutrophils from a patient with the Wiskott-Aldrich syndrome (WAS) were exposed to stimuli that activate specific membrane receptor or directly initiate biochemical events (e.g. the Ca2+ ionophore A23187 and ionomycin or arachidonic acid). Platelets from this patient did not aggregate in response to ADP, collagen, thrombin or adrenaline, which activate specific membrane receptors. Platelet aggregation, however, was normal in response to compound A23187, ionomycin or exogenous arachidonic acid. Histamine release from basophils of the WAS patient was normal in response to anti-IgE, a formylated peptide (f-met peptide), and to A23187. Similarly, the release of the lysosomal enzymes, beta-glucuronidase and lysozyme, from neutrophils of the WAS patient in response to serum treated zymosan (Zx), f-met peptide, and A23187 was not significantly different from that of his parents and 13 normal donors. These results suggest that the primary defect in WAS is selectively present in platelets and is located in a biochemical step between receptor activation and Ca2+ influx and/or initiation of arachidonate metabolism.
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PMID:The Wiskott-Aldrich syndrome: studies of platelets, basophils and polymorphonuclear leucocytes. 242 57

The effects of prostaglandin E1 (PGE1) and histamine on activation of superoxide (O2-) formation, exocytosis of beta-glucuronidase and aggregation in human neutrophils and HL-60 leukemic cells were studied. PGE1, histamine and impromidine, a potent H2-agonist, inhibited O2- formation in neutrophils induced by the chemotactic peptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMet-Leu-Phe) with IC50 values of 0.5 microM, 8 microM and 2 microM, respectively. The full H1-agonist and weak partial H2-agonist, betahistine, was much less potent and effective than histamine. Dibutyryl cyclic AMP and forskolin mimicked the effects of histamine and PGE1 on O2- formation. The H2-antagonist, famotidine, competitively reversed histamine-induced inhibition of O2- formation with a pA2 value of 7.5. Histamine inhibited O2- formation when added prior to or after fMet-Leu-Phe. fMet-Leu-Phe-induced aggregation and release of beta-glucuronidase in neutrophils were less sensitive to inhibition by PGE1, histamine, dibutyryl cyclic AMP and forskolin than O2- formation. The inhibitor of cyclic AMP-specific phosphodiesterase, rac-4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (Ro 20-1724), additively enhanced the inhibitory effects of histamine and PGE1 on the above cell functions. In HL-60 cells differentiated by dimethyl sulfoxide or dibutyryl cyclic AMP, histamine, impromidine and PGE1 but not betahistine inhibited fMet-Leu-Phe-induced O2- formation as well. Our data suggest that histamine inhibits activation of neutrophils and HL-60 cells via H2-receptors through activation of adenylyl cyclase and increased formation of cyclic AMP.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Histamine inhibits activation of human neutrophils and HL-60 leukemic cells via H2-receptors. 255 36

Histamine inhibits the in vitro release of granulocytic lysosomal beta-glucuronidase when incubated with complement activated zymosan particles and this is an H2-receptor response. The highly specific histamine H2-receptor agonist, dimaprit, also inhibits this secretory enzyme release but is less potent (-log molar ED50 6.71 with histamine vs. -log ED50 5.97 with dimaprit, p less than 0.05). No change in beta-glucuronidase release was found with the H1-agonst, 2-(2 pyridyl)-ethylamine. The antagonist activity of metiamide was similar with the two agonists (KB = 2.9 x 10(-8) M with histamine and KB = 3.6 x 10(-8) M with dimaprit). Diphenhydramine did not change the granulocyte response to either histamine or dimaprit.
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PMID:Dimaprit inhibition of zymosan-stimulated beta-glucuronidase release from human granulocytes. 644 28

Rat mast cell granules contain a spectrum of enzymes as established by histochemical techniques and subcellular fractionation. However, 35% of the beta-glucuronidase, 30% of the beta-D-galactosidase, 14% of the beta-hexosaminidase and all of the acid phosphatase is not available for immunologic release from purified rat serosal mast cells, suggesting the presence of nonsecretory lysosomes containing these acid hydrolases. On the other hand, immunologic release of the majority of chymase, beta-hexosaminidase, beta-glucuronidase, beta-D-galactosidase, and arylsulfatase A occurs in parallel with histamine and thereby localizes these substances to the rat mast cell secretory granule. A molecular model of the secretory granule in the resting mast cell can now be constructed in which heparin proteoglycan is the granule matrix to which chymase and probably other proteins are ionically bound. Inhibition of chymase by serotonin stored in its active site and of chymase and acid hydrolases by their interaction with heparin probably occurs. Histamine is stored by ionic linkage to carboxyl groups of protein and heparin. Micromolar amounts of heparin glycosaminoglycans, histamine, serotonin, chymase, beta-D-hexosaminidase, beta-glucuronidase, and arylsulfatase A in secretory granules of 10(6) mast cells are 0.7--1.3 x 10(-3), 70--220 x 10(-3), 0.9--28 x 10(-3), 0.2--0.5 x 10(-3), 0.9--2.7 x 10(-6), 0.1--0.3 x 10(-6) and less than 8 x 10(-6), respectively. In addition, the total protein available for calcium ionophore-induced release from 10(6) rat mast cells is about 60 microgram, indicating that less than 50% of the granule protein can be accounted for. Recognition that mast cell secretory granules contain acid hydrolases indicates that they are modified lysosomes; their special intracellular and extracellular functions are dictated by the associated novel constituents and the stimulus for activation.
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PMID:Enzymes of the mast cell granule. 677 34

Granulocytes from 21 nonasthmatic cystic fibrosis (CF) patients were isolated and the effects of isoproterenol, histamine, and prostaglandin E1 upon zymosan-induced beta-glucuronidase release was measured. Granulocytes from CF patients contained significantly less total beta-glucuronidase activity compared with those from control subjects, but response to zymosan stimulation was normal. Compared with those from control subjects, the granulocytes from CF patients with severe airway disease (% predicted FEV1 less than 60) had significantly reduced responsiveness to isoproterenol, which correlated with both the % predicted FEV1 values and the NIH clinical score. In this same population of CF patients, granulocyte responsiveness to PGE1 was also decreased compared with that of the control subjects, but the degree of impairment was not as severe as that observed with isoproterenol nor did it correlate with disease severity. Histamine responsiveness, however, was normal. Our findings suggest that abnormal beta-adrenergic responses may reflect the severity of airway disease and clinical score.
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PMID:Analysis of granulocyte beta-adrenergic response in cystic fibrosis: correlation of decreased responsiveness with disease severity. 727 Oct 56

A combined in vivo and in vitro study was undertaken with rats to test the hypothesis that zinc would protect against cold water immersion--restraint gastric ulcers, and that this phenomenon was mediated in part by stabilization of lysosomal membranes. This postulate was confirmed by observed activity changes in released beta-glucuronidase in mucosal tissue, as well as by dose-response in vitro data on isolated hepatic lysosomes exposed to zinc. Histamine, a known ulcer-enhancing agent, induced the opposite effect and increased the lysosomal release of this marker acid hydrolase.
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PMID:Studies of zinc and histamine on lysosomal fragility: possible role in stress ulceration. 740 19


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