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)

Ca2+, Mg2+-ionophores X537A and A23,187 (10(-7)-10(-6) M) induced the release of adenine nucleotides adenosine diphosphate (ADP, adenosine triphosphate (ATP), serotonin, beta-glucuronidase, Ca2+, and Mg2+ from washed human platelets. Enzymes present in the cytoplasm or mitochondria, and Zn2+ were not released. The rate of ATP and Ca2+ release measured by firefly lantern extract and murexide dye, respectively, was equivalent to that produced by the physiological stimulant thrombin. Ionophore-induced release of ADP, and serotonin was substantially (approximately 60%) but not completely inhibited by EGTA, EDTA, and high extracellular Mg2+, without significant reduction of Ca2+ release. The ionophore-induced release reaction is therefore partly dependent upon uptake of extracellular Ca2+ (demonstrated using 45Ca), but also occurs to a significant extent due to release into the cytoplasm of intracellular Ca2+. The ionophore-induced release reaction and aggregation of platelets could be blocked by prostaglandin E1 (PGE1) or dibutyryl cyclic AMP. The effects of PGE1, and N6, O2-dibutyryl adenosine 3':5'-cyclic monophosphoric acid (dibutyryl cAMP) were synergistically potentiated by the phosphodiesterase inhibitor theophylline. It is proposed that Ca2+ is the physiological trigger for platelet secretion and aggregation and that its intracellular effects are strongly modulated by adenosine 3':5'-cyclic monophosphoric acid (cyclic AMP).
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PMID:Human platelet secretion and aggregation induced by calcium ionophores. Inhibition by PGE1 and dibutyryl cyclic AMP. 17 96

The effects of dexamethasone sodium phosphate (DSP), 5 mg/kg, administration on the biochemical alterations in hepatic tissue subsequent to the production os splanchnic artery occlusion (SAO) shock was investigated. Following the induction of SAO shock, DSP-treated dogs exhibited a significantly improved cardiovascular status compared to placebo-treated shocked dogs, 2 hr after release of the occlusion, biopsies of the liver were taken and analyzed for beta-glucuronidase (BG), adenosine-3',5'-cyclic monophosphate (cAMP) and guanosine-3',5'-cyclic monophosphate (cGMP) content. SAO shock produced a significant increase in hepatic free BG activity which was reversed by DSP pretreatment. Additionally, SAO shock decreased hepatic cAMP levels, increased cGMP levels and significantly lowered the hepatic ratio of cAMP/cGMP. These changes in cyclic nucleotide levels were reversed by DSP administration and were found to be inversely related to changes in hepatic free BG activity. Thus, the ratio of cellular cAMP/cGMP may function as a regulatory mechanism for lysosomal enzyme release secondary to ischemia and hypoxia. Further, DSP may act to maintain lysosomal integrity in ischemic tissues by preservation of cAMP/cGMP ratios.
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PMID:Alterations in splanchnic cyclic nucleotide levels in splanchnic artery occlusion shock and their modification by dexamethasone. 17 27

Antishock effect of N6, O2-dibutyryl cyclic AMP (DBcAMP) Was investigated in rats subjected to Noble-Collip drum trauma and compared with effects of hydrocortisone and Trasylol. Results obtained are as follows. 1)Hydrocortisone and Trasylol administered 1 hr before initiating drumming improved the survival rate from traumatic shock with concomitant reducton of levels of acid phosphatase and beta-glucuronidase in circulating blood. DBcAMP administered i.p. immediately after trauma also improved the survival rate to the same extent as did Traylol or hydrocortisone, while no inhibitory effects were observed on acid phosphatase and beta-glucuronidase. 2)The rectal temperature fell significantly after suffering trauma, and the rats with greater fall in rectal temperature had poorer chance for survival. The fall in rectal temperature was considerably prevented by DBcAMP in a dose of 0.5 mg/100 g body weight (b.w.). 3)DBcAMP induced a rise in plasma insulin level (IRI) and insulin/glucose ratio (I/G) in shock rats, and the elevation in blood lactate/pyruvate ratio (L/P) and excess lactate otherwise observed after trauma were satisfactorily prevented by DBcAMP administration. It is concluded that the antichock effects of DBcAMP primarily resulted from improvements of the intracellular metabolism induced by its easy passage through the cell membrane and its cAMP like action, while any preventive action was not observed against elevation of lysosomal enzymes in the circulating blood.
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PMID:Experimental study of dibutyryl cyclic AMP: its antishock effects observed in traumatic shock rats. 18 67

Following intraperitoneal injection of actinomycin D rats show a decrease in number of cells present in the peritoneal cavity, reaching the lowest point after 24 hr. At the same time a highly significant increase of free beta-glucoronidase and of the intracellular concentrations of both cyclic AMP and cyclic GMP has been observed. No exudate was present at this time. Measurable quantities of exudate were present 48-72 hr after actinomycin injection concomitantly with an intense cellular immigration, the dominant cell being mononuclears. In this second phase of the reaction the free beta-glucuronidase decreases towards normal values and both the cyclic nucleotides are significantly below the control values. It is suggested that the increase of intracellular cAMP--concomitant with the maximum release of lysosomal enzymes--is a feedback mechanism preventing further release of inflammatory mediators.
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PMID:Actinomycin D peritonitis in the rat. 18 91

The injection of 50 microgram i.p. of actinomycin D produces, in rats, a biphasic inflammatory reaction. The first short lasting phase (approximately 24 h) is characterized by the decrease of the peritoneal cells number, by the increase of the levels of both cAMP and cGMP in the peritoneal cells and by the increased synthesis and release of lysosomal enzymes from these cells. The second long lasting phase (greater than 120 h) is characterized by the exudate formation, intense cellular immigration, continuous release of lysosomal enzymes, return to or below the normal values of the intracellular levels of cyclic nucleotides. The treatment of rats with a steroidal drug reduces the beta-glucuronidase release and, concomitantly, the intracellular cyclic nucleotides levels. Indomethacin is ineffective.
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PMID:Actinomycin D peritonitis in rats: a tool for the study of early events in inflammation. 19 11

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 effect of N6,O2'-dibutyryl adenosine 3',5'-cyclic-monophosphate (dbcAMP) on the mobilization of calcium (Ca2+), inorganic phosphate (Pi) and lysosomal enzymes was studied in a bone culture system for 24 h using half calvaria from 6--7 day-old mice. DbcAMP inhibited spontaneous as well as parathyroid hormone-stimulated mineral mobilization. DbcAMP in a concentration of 5 x 10(-4)M also reduced the activities of beta-glucuronidase, beta-galactosidase and acid phosphatase found in the media while the activities of lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were not affected. It is concluded that cAMP is not a stimulator but an inhibitor of bone resorption within the culture period studied (24 h) and that the cyclic nucleotide might interfere with release processes involved in bone resorption.
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PMID:Inhibitory effect of dibutyryl cyclic AMP on the release of calcium, inorganic phosphate and lysosomal enzymes from calvarial bones cultured for 24 hours. 22 6

We have shown previously that expression of the Dictyostelium ras gene DdrasD (previously denoted Ddras) is induced during multicellular development and in single-cell shaking culture in response to cAMP (1). Analysis of transformants carrying DdrasD/lacZ reporter constructs showed DdrasD expression to be prestalk-specific (2). The gene is transcribed from three start sites with transcription from the distal site producing an approximately 1.2 kb transcript, which is expressed at low levels in growing cells and is subsequently induced late in aggregation. This promoter is also induced to high levels by cAMP. Transcription from the two more proximal sites is coregulated and is induced during development, resulting in approximately 1.0 kb transcripts. In this study, we examine cis-acting regions required for proper regulation of DdrasD expression using a DdrasD/beta-glucuronidase reporter gene construct. We have identified distinct sequence elements required for developmental and vegetative expression of DdrasD. A domain containing a CA repeat, similar to ones found in other late, cAMP-induced Dictyostelium genes, is required for cAMP-induced and developmental expression.
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PMID:Regulation of the Dictyostelium cAMP-induced, prestalk-specific DdrasD gene: identification of cis-acting elements. 131 67

Human neutrophils and dibutyryl-cAMP (Bt2cAMP)-differentiated HL-60 cells possess receptors for the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMet-Leu-Phe), which mediate activation of phospholipase C, with subsequent increase in cytosolic Ca2+ concentration ([Ca2+]i) and activation of specific cell functions. In many cell types, histamine, via H1 receptors, activates phospholipase C, but it is unknown whether neutrophilic cells possess functional H1 receptors. We compared the effects of histamine with those of fMet-Leu-Phe on activation of these cells. In Bt2cAMP-differentiated HL-60 cells, substances increased [Ca2+]i in the effectiveness order fMet-Leu-Phe greater than histamine greater than betahistine. Pertussis toxin diminished fMet-Leu-Phe-induced rises in [Ca2+]i to a greater extent than those induced by histamine. H1 but not H2 antagonists inhibited histamine- and betahistine-induced rises in [Ca2+]i. fMet-Leu-Phe and histamine activated phospholipase C and increased [Ca2+]i through release of Ca2+ from intracellular stores and sustained influx of Ca2+ from the extracellular space. The substances also induced Mn2+ influx. Ca2+ and Mn2+ influxes were inhibited by 1-(beta-[3-(4-methoxyphenyl)propoxyl]-4-methoxyphenethyl)-1H-imida zole hydrochloride (SK&F 96365). The stimulatory effects of histamine on [Ca2+]i were more sensitive to inhibition by 4 beta-phorbol 12-myristate 13-acetate than were those of fMet-Leu-Phe. Unlike fMet-Leu-Phe, histamine did not activate superoxide anion formation, release of beta-glucuronidase, and tyrosine phosphorylation. In neutrophils, histamine and betahistine did not induce rises in [Ca2+]i. Our data show that (i) in Bt2cAMP-differentiated HL-60 cells, histamine increases [Ca2+]i via H1 receptors coupled to pertussis toxin-sensitive and possibly, pertussis toxin-insensitive heterotrimeric regulatory guanine nucleotide-binding proteins, (ii) histamine activates nonselective cation channels, and (iii) unlike fMet-Leu-Phe, histamine is an incomplete secretagogue.
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PMID:Histamine increases cytosolic Ca2+ in dibutyryl-cAMP-differentiated HL-60 cells via H1 receptors and is an incomplete secretagogue. 138 Oct 43

Impairments in the respiratory burst and stimulus-response coupling were studied with respect to the increased rate of cell replication that occurred in HL60 cells during repetitive passages in cell culture. During a 45-week period of culture, HL60 cells developed a progressive increase in rate of replication. Concomitantly, undifferentiated cells developed an impairment in ATP-induced calcium mobilization. The percentage of cells that could be differentiated with dimethyl sulfoxide progressively diminished. Differentiated cells developed an impairment in both the respiratory burst and secretion of beta-glucuronidase. In addition, regulation of the respiratory burst by cAMP agonists including isoproterenol, adenosine, and prostaglandin E2 was reduced in rapidly proliferating cells. Thus, multiple changes in stimulus-response coupling occur during cell culture in association with an increase in rate of cell replication. It may be important to recognize progressive impairments in cell function in studies using repetitive samples of HL60 cells from a continuously maintained cell population. The observed impairments in stimulus-response coupling may be relevant to unregulated cell growth in neoplastic disease.
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PMID:Impaired stimulus-response coupling in association with increased growth rate of HL60 cells. 150 70


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