Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vivo effect of an herbal based, non-steroidal anti-inflammatory product, salai guggal, prepared from the gum resin exudate of Boswellia serrata and its active principle "boswellic acids" on glycosaminoglycan metabolism has been studied in male albino rats. The biosynthesis of sulfated glycosaminoglycans, as evaluated by the uptake of [35S]sulfate, and the content of glycosaminoglycans were measured in specimens of skin, liver, kidney and spleen. Statistical analysis of the data obtained with respect to the boswellic acids and salai guggal were compared with those of ketoprofen. A significant reduction in glycosaminoglycan biosynthesis was observed in rats treated with all of the drugs. Glycosaminoglycan content was found to be decreased in the ketoprofen-treated group, whereas that of the boswellic acids or salai guggal treated groups remained unaltered. The catabolism of glycosaminoglycans was followed by estimating the activities of lysosomal glycohydrolases, namely beta-glucuronidase, beta-N-acetylglucosaminidase, cathepsin B1, cathepsin B2 and cathepsin D, in tissues and by estimating the urinary excretion and hexosamine and uronic acid. The degradation of glycosaminoglycans was found to be reduced markedly in all drug-treated animals as compared to controls. The potential significance of boswellic acids and salai guggal was discussed in the light of changes in the metabolism of glycosaminoglycans.
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PMID:Studies on the metabolism of glycosaminoglycans under the influence of new herbal anti-inflammatory agents. 281 45

We have utilized the adenylate cyclase stimulator, cholera toxin, as a tool to test the role of cyclic AMP as a mediator of the effects on bone resorption by the calcium-regulating hormones, parathyroid hormone (PTH) and calcitonin. The effects on bone resorption were studied in an organ culture system using calvarial bones from newborn mice. Cyclic AMP response was assayed in calvarial bone explants and isolated osteoblasts from neonatal mouse calvaria. Cholera toxin caused a dose-dependent cAMP response in calvarial bones, seen at and above approx. 1-3 ng/ml and calculated half-maximal stimulation (EC50) at 18 ng/ml. The stimulatory effect of cholera toxin could be potentiated by the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX, 0.2 mmol/l). Cyclic AMP accumulation in the bones was maximal after 4-6 h, and thereafter declined. However, activation of the adenylate cyclase was irreversible and the total amount (bone + medium) of cAMP produced, in the presence of IBMX (0.2 mmol/l), increased with time, for at least 48 h. In osteoblast-like cells cholera toxin (1 microgram/ml) stimulated the cellular levels of cAMP with a peak after 60-120 min, which could be potentiated with IBMX. The total cAMP accumulation indicated an irreversible response. In short-term bone organ cultures (at most, 24 h) cholera toxin, at and above 3 ng/ml, inhibited the stimulatory effect of PTH (10 nmol/l) on 45Ca release from prelabelled calvarial bones. The inhibitory effect of cholera toxin (0.1 microgram/ml) on 45Ca release was significant after 6 h and the calculated IC50 value at 24 h was 11.2 ng/ml. Cholera toxin (0.1 microgram/ml) also inhibited PTH-stimulated (10 nmol/l) release of Ca2+, inorganic phosphate (Pi), beta-glucuronidase, beta-N-acetylglucosaminidase and degradation of organic matrix (release of 3H from [3H]proline-labelled bones) in 24 h cultures. 45Ca release from bones stimulated by prostaglandin E2 (1 mumol/l) and 1 alpha-hydroxyvitamin D3 (0.1 mumol/l) was also inhibited by cholera toxin (0.3 microgram/ml) in 24-h cultures. The inhibitory effect of cholera toxin on bone resorption was transient, and in long-term cultures (120 h) cholera toxin caused a dose-dependent, delayed stimulation of mineral mobilization (Ca2+, 45Ca, Pi), degradation of matrix and release of the lysosomal enzymes beta-glucuronidase and beta-N-acetylglucosaminidase.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effects of cholera toxin on cyclic AMP accumulation and bone resorption in cultured mouse calvaria. 282 May 4

Activities of a cathepsin B-like cysteine proteinase have previously been observed to correlate with the malignancy of several animal and human tumors. Plasma membrane fractions of some of these tumors have been found to be enriched in cathepsin B-like activity. We have determined the subcellular distribution of this enzyme and three additional lysosomal hydrolases (cathepsin H, beta-hexosaminidase, and beta-glucuronidase) in normal murine liver and six metastatic variants of the B16 melanoma. The tissues were fractionated initially by differential centrifugation followed by Percoll density gradient centrifugation of the light mitochondrial fraction. Two fractions were obtained: an L-2 fraction enriched in all four lysosomal hydrolases; and an L-1 fraction enriched in a marker enzyme for the plasma membrane. Cathepsin B-like and beta-hexosaminidase activities, but not the other hydrolase activities, were also found to be enriched in the L-1 fractions of the metastatic B16 tumors. We explored the nature of the association of the cathepsin B-like activity with the plasma membrane using fractions from the spontaneously metastatic B16 amelanotic melanoma. Activity could not be dissociated from the plasma membrane fraction by washing with a physiological salt solution suggesting that it was not adsorbed to this fraction nonspecifically, nor could it be displaced by mannose 6-phosphate or other sugars which compete for binding to the known lysosomal receptors. High salt concentrations, low concentrations of the mild detergent saponin, mild acidification, or phosphatidylinositol-specific phospholipase C did not elute the cathepsin B-like activity. However, activity was eluted by exposure to 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, a detergent used in the purification of integral membrane proteins. The B16 amelanotic melanoma plasma membrane-associated cathepsin B-like activity had a slightly higher pH optimum and was resistant to inactivation by neutral pH and to inhibition by three low molecular weight inhibitors of cysteine proteinases. The Ki values for inhibition by leupeptin and stefin A were 20-fold higher. The presence of a cathepsin B-like cysteine proteinase at the surface of metastatic tumor cells, particularly in a form which can retain activity at physiological pH and retain activity in the presence of extracellular proteinase inhibitors, may contribute to the focal dissolution of the extracellular matrix observed at sites of contact with invading tumor cells.
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PMID:Properties of a plasma membrane-associated cathepsin B-like cysteine proteinase in metastatic B16 melanoma variants. 282 39

The relationships between cAMP and hyaluronate hydrolases (HH) activity were studied in the renal tissue. Both the urine osmolality and the HH activity were increased in the papilla tissue of rats treated with cAMP. Incubation of mild homogenized cells prepared from kidney papilla with cAMP, resulted in a significant increase in the total HH activity and that of beta-glucuronidase and N-acetyl-beta-D-hexosaminidase, whereas the activity of hyaluronidase remained unchanged. The data obtained suggest that ADH effect on the HH activity is mediated by adenylate cyclase mechanism.
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PMID:[Effect of cyclic 3',5'-adenosine monophosphate on hyaluronate hydrolase activity in the renal papilla]. 282 25

In the present studies the in vivo and in vitro effects of erythromycin A and azithromycin, a new type of macrolide (Fig. 2.), were investigated upon extracellular release of lysosomal enzymes, beta-glucuronidase (beta-Gluc) and beta-N-acetylglucosaminidase (beta-Glm) by using two experimental model systems: in vivo-adjuvant-induced arthritis in rats and in vitro- human polymorphonuclear leucocytes (PMNL) exposed to bovine serum albumin/anti-bovine serum albumin (BSA/anti-BSA), immune complex. Administrations of erythromycin A or azithromycin at doses of 5, 10 and 15 mg/kg into rats one day prior and 2, 4, 6, 8 and 10 days after a single subplantar injection of Freund's complete adjuvant significantly (p less than 0.01) inhibited extracellular release of lysosomal enzymes tested in the synovial fluid of injected left hind paw. These effects were dose-dependent. Further, erythromycin A and azithromycin at concentrations of 10(-7) M, 10(-6) M and 10(-5) M significantly (p less than 0.01) reduced excocytosis of both lysosomal enzymes, beta-Gluc and beta-Glm from human PMNL initiated by BSA/anti-BSA in a dose-related fashion. However, azithromycin was by far more effective (p less than 0.01) in decreasing extracellular release of beta-Gluc and beta-Glm either in the in vivo or in vitro experiments in comparison with erythromycin A. Appropriate control experiments excluded the possibilities that erythromycin A or azithromycin interfered with activities of lysosomal enzymes or with test reagents. Also, in no instances was there enhanced release of a cytoplasmic enzyme LDH.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparative studies on the effects of erythromycin A and azithromycin upon extracellular release of lysosomal enzymes in inflammatory processes. 284 7

The purpose of this study was to compare the latencies of lysosomal enzymes (beta-glucuronidase, beta-N-acetylglucosaminidase, arylsulphatase and acid ribonuclease) in heart and in red and white skeletal muscle of male and female mice (Mus musculus). The unsedimentable, free activities together with releasable (Triton X-100, hypotonic shock and freeze-thawing treatments) and unreleasable, bound activities were assayed. The distribution of acid hydrolases to different fractions was strikingly heterogeneous. The most distinct differences occurred between the distributions of beta-glucuronidase and beta-N-acetylglucosaminidase. The differences between muscle types occurred in the activity levels of lysosomal enzymes, rather than in the fractional distributions. Sex-related differences were small and occurred mainly in the activity levels of heart muscle (higher in female mice). The results suggest that the heterogeneous distribution of lysosomal enzymes originates in the compartmental differences of lysosomal enzymes in muscle cells, rather than the differences in cell populations of different muscle types.
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PMID:Latency differences of lysosomal enzymes in cardiac and skeletal muscles of male and female mice. 286 81

Two well-known drugs that induce the liver microsomal enzyme system in man were administered to 3 different groups of healthy male volunteers. Antipyrine 1200 mg and rifampicin in two different doses of 600 mg or 1200 mg daily were given orally to each group over a period of seven days. The extent of liver microsomal enzyme induction was assessed by estimating antipyrine elimination, serum gamma-glutamyl-transferase (GGT) activity and the urinary excretion rate of 6-beta-hydroxycortisol. In addition, possible effects on renal enzymes were monitored by measuring gamma-glutamyltransferase (GGT) and beta-glucuronidase (GRS) urinary excretion rates before and after drug administration. The possibility of a direct toxic effect on the renal tubular epithelium following drug administration was assessed by the measurement of urinary beta-N-acetylglucosaminidase (AGS) activity, total protein and glucose. Antipyrine plasma clearance and 6-beta-OHF excretion rates increased significantly in the groups treated with antipyrine or rifampicin, while serum GGT activities were enhanced only following antipyrine. Antipyrine administration increased urinary GGT excretion both immediately and one week after cessation of drug administration, but no changes were found following the administration of rifampicin. GRS, AGS, total protein and glucose excretion in urine remained unchanged during and after the administration of each individual drug. Based on these findings, the increased urinary GGT excretion observed following antipyrine treatment may be due to an inducing effect on the renal tubular cells, as no evidence for a toxic renal damage was found.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effect of antipyrine and rifampicin on the excretion of renal enzymes in human urine. 289 83

The subcellular distribution of beta-glucuronidase acquired by deficient human fibroblasts during co-culture with peritoneal macrophages was compared with that taken up by receptor-mediated endocytosis. Labelled enzyme taken up via receptors was located initially in a low-density endosomal fraction and was transferred to lysosomes within a few minutes. The beta-glucuronidase acquired during 24 h of co-culture was present almost entirely within lysosomes and had a distribution profile identical with that of endogenous beta-hexosaminidase. Monensin prevented transfer of radiolabelled enzyme from endosomes to lysosomes and had a similar effect on the distribution of enzyme acquired by direct transfer, causing beta-glucuronidase to accumulate within endosomes. When the temperature was lowered from 37 degrees C to 19 degrees C, the rate of transfer of enzyme from endosomes to lysosomes was decreased during both direct transfer and indirect receptor-mediated endocytosis. These results show that a lysosomal enzyme acquired by direct transfer during cell-to-cell contact follows a similar intracellular route and has a similar distribution to that of enzymes taken up via cell-surface receptors.
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PMID:Intracellular localization of beta-glucuronidase in fibroblasts after direct transfer from macrophages. 290 40

Acid hydrolases were isolated from the lysosome fraction of beta-galactosidase-deficient human fibroblasts and from the mannose 6-phosphate containing medium in which they were grown. Nearly half of the total beta-hexosaminidase and beta-glucuronidase from both sources bound to Ricin specifically. Lysosomal beta-hexosaminidase, metabolically labelled with [35S]-methionine, was also fractionated on Ricin-agarose. SDS-PAGE of immunoprecipitates from Ricin-binding and non-binding fractions revealed approximately equivalent amounts of cross-reacting material at the appropriate MW. We interpret these results to mean that acid hydrolases which are segregated to lysosomes are exposed to trans-Golgi processing enzymes to about the same extent as enzymes which are secreted, and that segregation by the Man 6-P receptor occurs after transit through the trans-Golgi compartment.
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PMID:Ricin-binding properties of acid hydrolases from isolated lysosomes implies prior processing by terminal transferases of the trans-Golgi apparatus. 293 47

Levels of the lysosomal enzymes beta-glucuronidase and beta-hexosaminidase were determined in tissues from rats at 1-7 weeks after permanent bile duct occlusion (28 animals) and sham operation (16 animals). With increasing duration of bile duct occlusion, increasing levels were found in the liver and spleen, whereas levels were unaffected in the pancreas, kidneys, brain, muscle, and skin. Histochemical investigation showed that the lysosomal enzymes accumulated in the hepatocytes and in the increasing numbers of reticuloendothelial cells of the liver and spleen during cholestasis. No significant accumulation of lysosomal enzymes was seen in the pancreas. In preparations of isolated hepatocytes and non-parenchymal cells increased specific activity of lysosomal enzymes in cholestasis appeared in both cellular fractions. It is assumed that the serum increase of lysosomal enzymes in late cholestasis is partly due to a release from activated macrophages in the liver and spleen.
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PMID:Tissue content and localization of lysosomal enzymes in cholestatic rats. 294 Jun 72


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