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)

Rat liver membrane vesicles were exposed to acetaldehyde, with or without reduction of the resultant adducts formed. Superoxide anion production and degranulation of rat neutrophils, upon stimulation with the liver membrane vesicles, were measured by cytochrome c reduction before and after the addition of superoxide dismutase, and beta-glucuronidase release respectively. Preincubation with acetaldehyde significantly enhanced superoxide anion production by both the reduced and non-reduced membrane samples (1.7-fold and 4.4-fold, respectively). Preincubation with acetaldehyde significantly enhanced degranulation (1.5-fold) of neutrophils in response to the non-reduced membranes only. The reductive process itself caused a marked increase (2.4-fold) in the ability of the membrane vesicles to stimulate degranulation. Cytochalasin B, an inhibitor of phagocytosis, did not reduce degranulation, implying that it occurred as a consequence of cell surface stimulation. Neutrophil superoxide anion production and lysosomal enzyme release in response to acetaldehyde-altered liver cell membranes could be an important mechanism of hepatocyte injury in alcoholic liver disease.
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PMID:Superoxide anion production and degranulation of rat neutrophils in response to acetaldehyde-altered liver cell membranes. 301 4

The contribution of activated oxygen species to neutrophil-mediated degradation of basement membrane collagen was investigated. In preliminary experiments, pre-exposure of either albumin or glomerular basement membrane to neutrophil myeloperoxidase with H2O2 and chloride increased their susceptibility to proteolysis 2-3-fold. In the basement membrane model, neutrophils are stimulated by trapped immune complexes to adhere, produce oxidants and degranulate. Degradation, measured as the amount of hydroxyproline solubilised, was due to neutral proteinases, particularly elastase, and depended on cell number and the amount of proteinase released. Experiments with oxidant scavengers and inhibitors and with neutrophils from donors with chronic granulomatous disease or myeloperoxidase deficiency showed that oxidants did not affect degradation of the basement membrane when this was measured on a per cell basis. However, oxidative inactivation of the released granule enzymes occurred. Activities of elastase, beta-glucuronidase and lysozyme were 1.5-2-times higher in the presence of catalase, but were unaffected by superoxide dismutase or hydroxyl radical scavengers. Inactivation did not occur with chronic granulomatous disease or myeloperoxidase deficient neutrophils. When related to the activity of released elastase, or to other degranulation markers, collagen degradation was decreased in the presence of catalase, or with chronic granulomatous disease or myeloperoxidase deficient cells. This implies that the basement membrane was made more digestible by myeloperoxidase-derived oxidants, as occurred in the cell-free experiments. Taken together, the results indicate that neutrophil oxidants have two opposing effects. They increase the susceptibility of the collagen to proteolysis and inactivate the proteinases responsible.
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PMID:The effect of oxidants on neutrophil-mediated degradation of glomerular basement membrane collagen. 302 26

The effect of oxygen free radicals, generated by xanthine and xanthine oxidase, was studied on the release of lysosomal hydrolase from rat liver lysosomes in vitro. A lysosomal enriched subcellular fraction was prepared, using differential centrifugation technique, from the homogenate of rat liver. The biochemical purity of the lysosomal fraction was established by using the markers of different cellular organelles. Oxygen free radicals were generated in vitro by the addition of xanthine and xanthine oxidase. The release of lysosomal hydrolase (beta-glucuronidase) from the lysosomal fraction was measured. There was a 3 to 4 fold increase in the release of beta-glucuronidase activity in the presence of xanthine and xanthine oxidase when compared to that in the absence of xanthine and xanthine oxidase. In the presence of superoxide dismutase (SOD), a scavenger of oxygen free radicals, the xanthine and xanthine oxidase system was unable to induce the release of beta-glucuronidase activity from the lysosomes. Sonication (2 bursts for 15 sec each) and Lubrol (2 mg/10 mg lysosomal protein) treatment, which are known to cause membrane disruption, also induced the release of beta-glucuronidase from lysosomal fraction. This release of beta-glucuronidase by sonication and lubrol treatment was not prevented by SOD. These data indicate that lysosomal disruption is a consequence of oxygen free radicals, generated by xanthine and xanthine oxidase.
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PMID:Oxygen free radicals induced release of lysosomal enzymes in vitro. 323 Dec 25

Lipoperoxide changes and the effect of reduced glutathione (GSH) on that were investigated in cardiopulmonary bypass and endotoxin shock states. In human cardiopulmonary bypass, 26 patients with congenital heart disease were studied and the following results were obtained. Serum lipoperoxide concentration in control group increased in 30 and 60 min after bypass. On the other hand, in the reduced glutathione pretreatment group (100 mg/kg), this change was not observed. In both groups, beta-glucuronidase activity had a tendency to increase after bypass, and it had a close correlation between serum lipoperoxide concentration and beta-glucuronidase activity. In endotoxin shock rats, the results were as follows. 3 hours after injection of endotoxin (10 mg/kg), hepatic lipoperoxide concentration increased and superoxide dismutase (SOD) activity decreased, and hepatic Chemiluminescence counts had a tendency to increase. There was no significant change in serum lipoperoxide concentration after 3 hr, but a significant elevation was observed only after 6 hr. In the reduced glutathione pretreatment group (1,000 mg/kg), serum and hepatic lipoperoxide concentration, hepatic SOD activity, and hepatic Chemiluminescence counts were unchanged. These results suggest that lipoperoxide may increase in shock states and GSH administration may be useful to inhibit lipoperoxide formation.
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PMID:[The effect of reduced glutathione on the changes of lipid-peroxide concentration in shock states--clinical and experimental studies]. 399 53

Adjuvant arthritis was induced in rats by the injection of Mycobacterium tuberculosis, and its severity was scored according to the macroscopic findings of the legs, tail, and ears. The average score so obtained was lower in SOD-injected rats than in the control group. The depression of albumin/globulin ratio was inhibited significantly in rats treated with 10.0 mg/kg of SOD. The levels of acid phosphatase and beta-glucuronidase were elevated after the administration of an adjuvant, and these lysosomal enzymes showed a remarkable increase in the control rats, while the elevation was inhibited in rats injected with 10.0 mg/kg of SOD. The levels of TBA-reactive substances in the sera and synovia were elevated at 2 weeks after the injection of adjuvant and decreased thereafter. In rats injected with 5.0 mg/kg or 10.0 mg/kg of SOD, the increase in both serum and synovial levels of TBA reactants was inhibited significantly. These observations suggest that the aggravation of adjuvant arthritis may be associated with lipid peroxidation due to superoxide, and that SOD may be beneficial for the treatment of arthritis.
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PMID:The increase of lipid peroxidation in rat adjuvant arthritis and its inhibition by superoxide dismutase. 401 32

Human colostral macrophages stimulated by opsonized zymosan or phorbol myristate acetate (PMA) released superoxide anions (O2-) and hydrogen peroxide (H2O2) with activities comparable to those of monocytes and about one-fourth of those of polymorphonuclear leukocytes (PMNL) of blood. The O2- -forming oxidase in the macrophages stimulated by PMA was dependent on NADPH as an electron donor with an apparent Km value for NADPH of 27.6 +/- 4.0 microM, which is comparable to those obtained for the stimulated monocytes and PMNL of blood. The Vmax was 1.86 +/- 0.33 nmol O2/min/10(6) cells, which is essentially the same as that of monocytes and about half of that of PMNL. p-Chloromercuribenzoate or cetyltrimethylammonium bromide completely inhibited oxidases of all three types of phagocytes. A b-type cytochrome was identified in the macrophages but the concentrations in the macrophages and monocytes were less than half of that in PMNL. These results suggest that the differences in the O2- -forming activities of the three types of phagocytes are quantitative rather than qualitative. The macrophages and monocytes showed very low activities of myeloperoxidase [EC 1.11.1.7] in contrast to PMNL. The activity of beta-glucuronidase [EC 3.2.1.31] in the macrophages was much higher than those of the monocytes and PMNL, but little difference was observed in the activities of lysozyme [EC 3.2.1.17], catalase [EC 1.11.1.6] and superoxide dismutase [EC 1.15.1.1] among the three types of phagocytes examined. Electron micrographs of the macrophages showed little increase of vacuoles upon exposure to PMA, in contrast to the cases of monocytes and PMNL.
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PMID:Oxygen metabolism of human colostral macrophages: comparison with monocytes and polymorphonuclear leukocytes. 608

Neutrophils from the synovial fluid (SFN) of 10 patients with active rheumatoid arthritis (RA) were investigated to determine the generation of oxygen intermediates (OI) (O2-, H2O2, OH .), chemiluminescence, and lysosomal enzymes (lysozyme and beta-glucuronidase). Lymphocytes from healthy individuals were cocultured at 37 degrees C for 17 hr with SFN from the patients and the number of OKT4+, OKT8+, and OKT3+ cells and the response to mitogens were determined. A markedly increased OI and slightly elevated lysosomal enzyme levels were observed in SFN from patients. Coculture of lymphocytes with SFN resulted in a decreased number of OKT4+ and OKT8+ cells and a greatly reduced response to Con A and mildly diminished response to PHA, while OKT3+ cells were not affected. The simultaneous addition of superoxide dismutase and catalase restored the impairment of monoclonal antibody reaction and lymphocyte responsiveness almost to control levels. It is suggested that the disturbed immunoreactivity of synovial fluid lymphocytes from RA patients may be due to increased OI generated by stimulated neutrophils.
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PMID:Effect of stimulated neutrophils from the synovial fluid of patients with rheumatoid arthritis on lymphocytes--a possible role of increased oxygen radicals generated by the neutrophils. 660 65

The chromosome localization and gene synteny of soluble malate dehydrogenase (MDH1), soluble isocitrate dehydrogenase (IDH1), mitochondrial superoxide dismutase (SOD2), phosphoglucomutase-3 (PGM3), mitochondrial malate dehydrogenase (MDH2), beta-glucuronidase (GUSB), nucleoside phosphorylase (NP), pyruvate kinase M2 (PKM2), hexosaminidase A (HEXA), inosine triphosphatase (ITPA), and N-acetyl-alpha-D-galactosaminidase (NAGA) were determined in the rhesus monkey using somatic cell hybrids. Comparison with the human and Pongidae syntenic groups shows that chromosome banding homologies do not always correlate with gene mapping data.
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PMID:Complex chromosome homologies between the rhesus monkey (Macaca mulatta) and man. 682 71

During phagocytosis, neutrophils generate reactive oxygen metabolites and release lysosomal enzymes into the extracellular medium. We have investigated the possibility that these enzyme are inactivated by the oxygen compounds. Phagocytosing neutrophils from 12 patients with chronic granulomatous disease, which do not generate these oxygen metabolites, released two to three times more activity of lysozyme and beta-glucuronidase than did normal neutrophils. This difference proved to be due to a decrease of approximately 20% of the total activity of these enzymes in normal neutrophils, but not in neutrophils of patients with chronic granulomatous disease. This inactivation of enzymes took place during phagocytosis of opsonized zymosan particles as well as during stimulation of normal cells with phorbol myristate acetate. The inactivation was not due to formation of inhibitors. The lysosomal enzymes were not activated when the neutrophils were stimulated under anaerobic conditions. Addition of catalase, superoxide dismutase, or albumin gave no protection against the oxidative damage; reduced glutathione gave partial protection. The oxidative inactivation was more pronounced in the presence of azide. Measurement of the activity and the amount of protein of acid alpha-glucosidase in the cells showed that the specific activity of this enzyme decreased by approximately 50% during 30 min of phagocytosis. This indicates that the inactivation of the lysosomal enzymes takes place in the phagolysosomes, before the enzymes have leaked into the extracellular medium.
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PMID:Phagocytosing human neutrophils inactivate their own granular enzymes. 722 38

The lysosomal enzymes, acid-phosphatase and beta-glucuronidase, were released from rat liver lysosome when exposed to 400 nm irradiation in the presence of haematoporphyrin, and the release was prevented by adding vitamin E, diazabicyclo-octane, bovine serum albumin, superoxide dismutase or D-mannitol to the reaction mixture. Monochromatic irradiation with wavelengths from 380 to 410 nm caused no significant differences in the release of lysosomal enzymes, but 420 nm irradiation caused three-fifths of that of 400 nm irradiation. The malondialdehyde level in rat liver homogenate increased after 400 nm irradiation in the presence of haematoporphyrin. Reduction of nitroblue-tetrazolium was not observed when haematoporphyrin was excited by 400 nm; it was considered that superoxide anion radical (O2--) was not primarily generated. The following mechanism was assumed: that porphyrin which had been excited by 400 nm, converted ground-state molecular oxygen (3O2) to excited singlet oxygen (1O2), which formed lipid peroxides in lysosomal membrane resulting in destruction of the membrane; skin changes would occur from these released lysosomal enzymes.
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PMID:Lysosome destruction and lipoperoxide formation due to active oxygen generated from haematoporphyrin and UV irradiation. 737 79


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