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)

The pathobiology of the process of myocardial injury during ischemia comprises a series of events that results in the release of lysosomal enzymes from their subcellular locations within the myocardium. We have developed a canine model of acute myocardial ischemia in which the anterior descending coronary artery is ligated, myocardial blood flow is measured using radioactive microspheres, and tissues from subendocardium and subepicardium are assayed for activity of lysosomal hydrolases:N-acetyl-beta-glucosaminidase (NAG), beta-glucuronidase (beta-gluc), and acid phosphatase (AP). Particulate fractions of subendocardium revealed significant depletion of of total acid hydrolases (NAG, beta-gluc, and AP) after one and two hours of ischemia. In addition, after two hours of ischemia, the total activity of these three hydrolases in the subendocardial supernatant was decreased, correlating significantly with diminished myocardial blood flow (NAG: r =0.96; beta-gluc: r = 0.95; AP: r = 0.75). The diminished enzymatic levels in thesupernatant suggested "washout" of the hydrolases that was more efficient in those ischemic areas that had higher myocardial flow (greater than 20% of control). These changes in distribution of lysosomal hydrolases indicate early involvement of these enzymes in the pathobiology of myocardial injury and demonstrate the dynamic relationship of "washout" of acid hydrolases with the degree of diminished blood flow.
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PMID:Release of lysosomal enzymes during ischemic injury of canine myocardium. 103 97

Cell differentiation during spermatogenesis in the rat has been analyzed in terms of the formation of specific "marker" enzymes. Hyaluronidase and other acrosomal enzymes are formed in spermatids according to a highly predictable time schedule which may be termed a "molecular biological clock". The acrosomal enzymes beta-galactosidase and N-acetyl-beta-glucosaminidase exist as isoenzyme forms distinct from enzymes with similar substrate specificities in the lysosomes of precursor cells. Differentiation of spermatids thus involves the loss of gene expression for lysosomal enzymes and the activation of genes for acrosomal isoenzymes. Spermatogenesis is characterized by the sequential loss of expression of many genes, as evidenced by the loss of beta-glucuronidase in the differentiation of spermatogonia to spermatocytes, and the loss of uridine diphosphatase activity in the differentiation of spermatocytes to spermatids. The apparent absence of ornithine decarboxylase activity from spermatids suggests a dependence of these cells upon Sertoli cells for the provision of putrescine and/or spermidine. Such biochemical cooperativity among germinal cells may be necessary as the genes of spermatids are repressed and late spermatids become metabolically inactive. Spermatogenesis is also characterized by changes in the cellular content and rates of synthesis and phosphorylation of specific acidic chromatin proteins. It is hypothesized that these proteins may participate in the activation or repression of genes during spermatogenesis.
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PMID:Gene activation during spermatogenesis. 112 12

Early changes in lysosomal enzymes must occur if their role is significant in irreversible myocardial injury. Therefore, we ligated the anterior descending coronary artery in 14 dogs and after 60 min excised epicardial and endocardial samples from the ischemic and adjacent normal heart. The collateral flow measured with radioactive microspheres in the endocardial samples averaged 19% of control. The muscle was disrupted and fractionated by ultracentrifugation into nuclear pellet (NP), heavy lysosomal pellet (HL), light lysosomal pellet (LL), microsomal pellet (M) and supernate (S). Electron microscopy demonstrated changes characteristic of sichemia in whole tissues and sedimented fractions. Acid phosphatase reaction product was present in residual bodies in the HL fraction and membrane-bound vesicles in the LL fraction and in the intact tissue. Significant decreases in the specific activity of N-acetyl-beta-glucosaminidase and beta-glucuronidase occurred in the endocardial LL fraction, while significant increases in both were found in the ts fraction (P less than 0.05). Losses of acid phosphatase occurred in both LL and S fractions. Moreover, decreases of total N-acetyl-beta-glucosaminidase in the HL fraction and of total beta-glucuronidase and acid phosphatase in the LL fraction were positively correlated (P less than 0.01) with the degree of ischemia measured with radioactive microspheres. Only insignificant enzymatic changes were found when the collateral flow was greater than 40%, and the differences were less significant in epicardial samples where the flow averaged 29%. The early loss of enzymes from the lysosomal fractions in severe ischemia suggests a role for lysosomal hydrolases in the necrosis that follows coronary occlusion.
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PMID:Effect of collateral flow on epicardial and endocardial lysosomal hydrolases in acute myocardial ischemia. 115 94

Sequential evaluations were made of the morphology and biochemistry of trigeminal nerves from control and ethylnitrosourea (ENU)-exposed rats from 1 day to 6 months of age. Distinct increases in cellularity were evident as early as 20 days after exposure to ENU. Corresponding increases in N-acetyl-beta-glucosaminidase and beta-glucuronidase were detected at the same time. Transplantation studies were performed with grossly normal trigeminal nerves from 32-, 63-, and 91-day-old control and ENU-exposed rats. One of eight nerves from the 32-day-old ENU-exposed donors developed into neurinomas at the site of transplantation. No tumors developed from nerves of controls. These results indicate that the early increases in cellularity and acid hydrolase activities represent neoplastic rather than preneoplastic changes.
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PMID:Sequential development of ethylnitrosourea-induced neurinomas: morphology, biochemistry, and transplantability. 115 7

Human gallbladder epithelium was homogenized with a view to maintaining the integrity of subcellular components. In such homogenates, N-acetyl-beta-glucosaminidase, beta-glucuronidase, beta-galactosidase, beta-glucosidase, beta-fucosidase, beta-xylosidase, and acid phosphatase were demonstrated together with phospholipase activity. All the enzymes exhibited structure-linked latency. After discarding cellular debris from the homogenate, remaining subcellular organelles were analytically separated by density gradient centrifugation. After 100,000 g for 1 hour, particles containing acid glycosidases were recovered at a sucrose density of 1.18-1.19, whereas the mitochondrial marker enzyme succinate-reductase accumulated at a density of 1.16. The bulk of sedimentable phospholipase activity was recovered with particles sedimenting at 1.18-1.19. The results are interpreted as indicating that phosphalipase is present in lysosomes of the human gallbladder epithelium. Release of acid hydrolases, in lysosomes of the human gallbladder epithelium. Release of acid hydrolases, in lysosomes of the human gallbladder epithelium. Release of acid hydrolases, particularly phospholipase A, from the gallbladder epithelium is discussed as mediation of an inflammatory reaction in the gallbladder, i.e. cholecystitis.
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PMID:On the mediation inflammatory reaction in the human gallbladder epithelium. 127 7

1. A mixed membrane fraction prepared from pig platelets was subfractionated, using the "B 14" zonal rotor, into two distinct subpopulations of membrane vesicles, each associated with a different phosphodiesterase activity. 2. The lighter subfraction (MI) was enriched 7-8 fold with bis-(p-nitrophenyl) phosphate phosphodiesterase activity and the denser subfraction (MII) showed a similar degree of enrichment of 5'dTMP-p-nitrophenyl ester phosphodiesterase activity. 3. Assays for other enzyme activities revealed slight enrichement (approx. 2 fold) of acid phosphatase, 3'-dTMP-p-nitrophenyl ester phosphodiesterase and beta-glucuronidase activities in MI, and beta-galactosidase in MII. Cyclic AMP phosphodiesterase, lactate dehydrogenase and N-acetyl-beta-glucosaminidase showed negligible activity in both MI and MII, and succinate dehydrogenase activity could not be detected in either subfraction. 4. Chemical analyses of the membrane subfractions demonstrated that MI contained approx. twice as much cholesterol, phospholipid, sialic acid and hexosamine per unit weight of protein than MII. These results are consistent with our previously reported observations from surface-labelling experiments, which indicated that MI was derived principally from the platelet surface-exposed membranes and that MII was probably intracellular in origin. 5. Analysis of the membrane polypeptides by sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the presence of 12-15 components, in each subfraction, in the mol. wt. range 12000-200000, including a prominent band of approx. mol. wt. 46000, which has beeen identified to be actin. Qualitative as well as possible quantitative differences were apparent in that MII contained three components in addition to those present in MI. 6. Analysis of the periodate-Schiff staining components by sodium dodecyl sulphate-polyacrylamide gel electrophoresis demonstrated the presence of 4 major glycoproteins in both subfractions with apparent mol. wt. ranging from approx. 95000 to 150000; in addition two minor components were also present. Further, a very fast-migrating band, which did not stain with Coomassie blue, was observed in both MI and MII and probably represents lipid material.
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PMID:Enzymatic and chemical analyses of pig platelet membrane subfractions isolated by zonal centrifugation. 127 16

Several lysosomal enzymes present in human plasma (N-acetyl-beta-glucosaminidase, beta-glucuronidase, beta-galactosidase, alpha-galactosidase, alpha-L-fucosidase, alpha-mannosidase, beta-glucosidase) were maintained in a fully active state for at least 8 months by the addition of ethylene glycol (300 milligrams final concentration) to freshly prepared plasma and storage at -20 degrees C. Pools of human plasma from healthy humans, stabilized and stored as above, and containing a low, medium or high content of the above enzymes, were used to establish the analytical imprecision (within-run, day-to-day and total imprecision) of the fluorimetric assay. Ten replicates in ten different analytical series, covering a period of two months, were performed. The total imprecision (expressed as coefficient of variation) was in general lower than 10%; in a few cases, particularly plasma samples with a low enzyme content, the total imprecision was 18%. The isozymes A, B, I1, and I2 of N-acetyl-beta-glucosaminidase displayed the same stability upon storage as the unfractionated enzyme. It is concluded that pools of human plasma containing known amounts of lysosomal enzymes, stabilized by the addition of 300 micrograms ethylene glycol and stored at -20 degrees C, are suitable liquid materials for calibration and quality control for the assay of the same enzymes.
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PMID:Preparation of a stable liquid material for calibration and quality control for lysosomal enzymes in plasma. Assay of enzymes of lysosomal origin in plasma, I. 133 72

To evaluate the effects of acute pancreatitis on hepatic function and hepatic cellular and subcellular organellar fragility, we studied 1) the hepatic secretion of lysosomal enzymes (beta-glucuronidase, beta-galactosidase, and N-acetyl-beta-glucosaminidase) into bile in the isolated perfused rat liver model; 2) the aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), and lysosomal enzyme levels in the effluent in an isolated liver model; 3) hepatic lysosomal fragility in an in vitro incubation study; and 4) protective effects of a new low molecular weight synthetic protease inhibitor, ONO 3307, against hepatic injury in doses of 2 and 5 mg/kg.h in acute pancreatitis induced by a supramaximal dose of cerulein in rats. Decreased hepatic secretion of lysosomal enzymes into bile and accelerated hepatic lysosomal fragility were observed in acute pancreatitis induced by cerulein. ONO 3307 showed a significant protective effect against this hepatic injury in acute pancreatitis, the dose of 5 mg/kg.h showing a more potent effect than the dose of 2 mg/kg.h. These results suggest that the impaired hepatic function, including depressed hepatic secretion of lysosomal enzymes, seems to be closely related to accelerated hepatic fragility and that some unknown protease, which is present in pancreatitis and is susceptible to inhibition by ONO 3307, plays a crucial pathologic role in the development of this liver injury during acute pancreatitis.
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PMID:Effects of acute pancreatitis on hepatic secretion of lysosomal enzymes into bile and hepatic lysosomal fragility: protective effects of a new synthetic protease inhibitor, ONO 3307. 150 86

Primary microcultures of human amnion epithelial cells were established, starting from sterile term placentae. Over a period of 1 week in culture, the epithelial cells release into the extracellular medium substantial amounts of some lysosomal hydrolases, such as sphingomyelinase, N-acetyl-beta-glucosaminidase, alpha-fucosidase, beta-glucuronidase, alpha-mannosidase, and arylsulfatase. Judging from experiments conducted with the protein synthesis inhibitor, cycloheximide, the enzymes released are not newly synthesized forms, but very likely derive from lysosomes. The constitutive secretion of lysosomal enzymes, coupled with lack of immunogenicity, makes amnion epithelial cells a convenient source of enzymes for implantation in attempts of enzyme replacement therapies.
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PMID:Secretion of lysosomal hydrolases by cultured human amnion epithelial cells. 205 67

The contribution of neutrophil-derived elastase and cathepsin G to joint pathology has been examined in immune arthritis in the mouse. Neutrophils from beige mice are genetically deficient in lysosomal elastase and cathepsin G, but have normal levels of the acid hydrolases, beta-glucuronidase, and N-acetyl-beta-glucosaminidase. The development of antigen-induced arthritis in normal mice has been compared with that in beige mice. The pattern of synovitis (both leukocyte accumulation and plasma leakage) were indistinguishable in normal and beige mice. Cartilage proteoglycan depletion was quantified by measuring the decrease in safranin O staining intensity, and this, too, was unaltered in mice lacking elastase and cathepsin G. These results suggest that neutrophil elastase and cathepsin G do not contribute to these aspects of joint pathology in antigen-induced arthritis in the mouse.
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PMID:Pathogenesis of antigen-induced arthritis in mice deficient in neutrophil elastase and cathepsin G. 224 Jan 59


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