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)

Quercetin inhibited in a concentration-dependent manner the release of beta-glucuronidase from human polymorphonuclear leukocytes stimulated with zymosan-activated serum. 3H-arachidonic acid-prelabelled polymorphonuclear leukocytes released 3H-arachidonic acid upon stimulation with zymosan-activated serum and this was associated with a decrease of radioactivity in the phospholipid fraction as determined by thin layer chromatography. Quercetin inhibited the release of 3H-arachidonic acid. These observations suggest that the zymosan-activated serum stimulus activates phospholipase A2 and that phospholipase A2 is inhibited by quercetin. Thus, quercetin alters polymorphonuclear leukocyte phospholipid metabolism and responses to stimulation.
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PMID:Effect of quercetin on human polymorphonuclear leukocyte lysosomal enzyme release and phospholipid metabolism. 681 14

The effects of the stable analogue of TxA2, U46619, on polymorphonuclear leukocyte (PMN) function were investigated. U46619, at micromolar concentrations, inhibited fMLP-stimulated aggregation, beta-glucuronidase release, and superoxide production. fMLP-induced LTB4 synthesis was also inhibited. U46619 did not modify intracellular Ca2+ increase induced by fMLP in Fura-2-loaded PMN, suggesting that early events of cell activation were not involved. In fact, U46619 also inhibited aggregation, beta-glucuronidase release, superoxide anion and LTB4 production induced by the calcium ionophore A23187. By comparison with the specific 5-lipoxygenase inhibitor, L-663,536, which prevented LTB4 synthesis without affecting degranulation, we excluded the impairment of PMN function by U46619 as a consequence of the reduction of this endogenous agonist. TLC separation of lipid extracts from [3H]-AA-loaded PMN, stimulated by A23187, showed significant reduction of the radioactivity associated with authentic free AA, suggesting that U46619 could interfere with mechanisms regulating AA release from membrane phospholipids. This suggestion is also supported by the observation that manoalide, a standard inhibitor of phospholipase A2, similarly to U46619, inhibits beta-glucuronidase release from stimulated PMN. Prostaglandin endoperoxides, produced by cells participating in inflammatory reactions, might therefore play a role in modulating PMN activities.
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PMID:The endoperoxides/TxA2 analogue, U46619, inhibits human polymorphonuclear leukocyte function. 782 74

The effects of (Z)-11-[(3-dimethylamino)propylidene]-6,11-dihydrodibenz [b.e.]oxepin-2-acetic acid monohydrochloride (KW-4679), an orally active antiallergic drug, on the production of platelet-activating factor (PAF), leukotriene (LT) and thromboxane (TX) induced by Ca2+ ionophore A23187 were examined. KW-4679 at 10 microM reduced the amount of cell-associated PAF by 52.8% in human polymorphonuclear leukocytes (PMNs). KW-4679 (1-100 microM) also inhibited the release of both LTB4 and TXB2, a stable metabolite of TXA2, by human PMNs in a concentration-dependent manner, but did not influence the release of beta-glucuronidase. The 50% inhibitory concentration (IC50) values for LTB4 and TXB2 release were 5.9 and 6.0 microM, respectively. In guinea pig eosinophils, KW-4679 inhibited the release of peptide LTs at a concentration higher than 10 microM (IC50 = 66.9 microM). KW-4679 failed to inhibit PAF acetyltransferase, 5-lipoxygenase and TX synthase, but inhibited the arachidonic acid release by human PMNs in a concentration-dependent manner in a similar concentration as that inhibiting production or release of lipid mediators (IC50 = 19.5 microM). These results indicate that KW-4679 suppresses LTs and TX release and PAF formation by reducing arachidonic acid release from phospholipids, probably through interference with phospholipase A2. The inhibitory action of KW-4679 on PAF, LT and TX production is a beneficial effect of an antiallergic drug.
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PMID:KW-4679, an antiallergic drug, inhibits the production of inflammatory lipids in human polymorphonuclear leukocytes and guinea pig eosinophils. 864 79


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