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)

Histochemical techniques have been used to study the chemical composition of the oesophageal gland secretions of Orthocoelium scoliocoelium and Paramphistomum cervi. Results suggest that the secretions contain numerous enzymes, e.g., non-specific alkaline and acid phosphatases, ATPase, TPPase, esterase (Cathepsin C like), beta-galactosidase, beta-glucuronidase and N-acetyl-beta-glucosaminidase. The role of these enzymes in the digestion of food in these amphistomes is discussed. On the basis of histological and histochemical studies the caecal epithelium of the two amphistomes has been found to be syncytial bearing regularly arranged numerous, long but equal-sized and closely packed cylindrical microvilli. The role of various hydrolytic enzymes in well fed and starved flukes in relation to their gastrodermis and microvilli has also been discussed.
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PMID:Role of oesophageal glands in the digestive physiology of two rumen amphistomes Orthocoelium scoliocoelium and Paramphistomum cervi. 684 57

The content of 5 lysosomal hydrolases was examined in the rat liver and blood serum after compression of hind limb soft tissues in the presence of a long-term intake of excess doses of pyridoxine, riboflavin and glutamic acid. It was shown that the 14-day application of the drug complexes dramatically increased the overall content of cathepsin C, arylsulfatases A and B, beta-glucuronidase and p-acetyl-beta-D-galactosaminidase and reduced the overall content of cathepsin D in the rat liver. The non-sedimented content of the enzymes did not practically differ from the control magnitudes. In the blood serum, the content of cathepsin C and B1 approximated that seen in the control, while that of arylsulfatases A and B and p-acetyl-beta-D-galactosaminidase decreased, whereas the beta-glucuronidase content was 75% higher as compared to the basic characteristics. In the presence of administering the drug complexes, severe mechanical injury entailed the lowering of the content of the majority of rat liver lysosomal hydrolases. Besides, one could observe an essential fall of the non-sedimented content of cathepsin C and arylsulfatases A and B. The blood serum demonstrated an appreciable decrease in the content of cathepsins C and B1, p-acetyl-beta-D-galactosaminidase and arylsulfatases A and B. Thus, the fall of the non-sedimented content and diminished release of lysosomal hydrolases into the systemic circulation attest to the preservation of the structural and functional integrity of the liver cell lysosomal system during severe mechanical injury in the presence of combined excess intake of pyridoxine, riboflavin and glutamic acid.
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PMID:[Effect of pyridoxine, riboflavin and glutamic acid on lysosomal hydrolase activity in the liver and serum of rats during traumatic stress]. 715 Jul 36

To determine the effects of lipid accumulation on proteoglycan synthesis, we studied proteoglycan biosynthesis in rabbit aortic smooth muscle cells in culture. Cholesterol-enrichment was accomplished by incubating confluent smooth muscle cells with cationized low-density lipoprotein. Control and cholesterol-enriched cells were incubated with [35S]sulphate, [3H]glucosamine, or [3H]serine. Metabolically labelled proteoglycans in the cell layer and medium were quantified. During a 20 h incubation period, proteoglycan synthesis in cholesterol-enriched cells increased by 40-50% above that in control cells. A similar increase in precursor incorporation into proteoglycans was also noted following a short 15 min pulse. The cholesterol-enriched cells also showed a 45-50% increase over control rates in the intralysosomal accumulation of a large chondroitin sulphate proteoglycan and a small dermatan sulphate proteoglycan. The enhanced synthesis of proteoglycans in cholesterol-enriched cultures was inhibited by cycloheximide and actinomycin D, which are inhibitors of protein synthesis and transcription respectively. Proteoglycan turnover was investigated by pulse-chase analysis. Following a 2-h pulse, intracellular proteoglycans in cholesterol-enriched cells disappeared, having a half-life of 26.5 h compared with 2.8 h for those in the control cells. The amount of trypsin-releasable proteoglycan was significantly reduced in cholesterol-enriched cells. In addition, the degradation of proteoglycans was severely retarded in cholesterol-enriched cultures. The activities of three acid hydrolases, N-acetyl-beta-hexosaminidase, beta-glucuronidase and cathepsin C, were significantly reduced in cholesterol-enriched cells compared with activities in control cells. The results indicate that proteoglycan metabolism is altered in cholesterol-enriched smooth muscle cells.
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PMID:Enhanced synthesis and accumulation of proteoglycans in cholesterol-enriched arterial smooth muscle cells. 837 76

The distribution of the cation-independent mannose 6-phosphate and 78 kDa receptors was studied in postnuclear subcellular fractions from two rat liver cell lines. ELISA assays revealed that the mannose 6-phosphate receptor is enriched in the light buoyant Percoll fractions that contain Golgi structures and early endosomes. Most of the 78 kDa receptor is localized in a heavy fraction at the bottom of the Percoll gradient and smaller amounts in the endosomal fractions. The high-density compartment is denser than lysosomes, contains LAMP2 but not LIMPII or acid hydrolases, and is not disrupted with glycyl-l-phenylalanine 2-naphthylamide, a substrate for cathepsin C that selectively disrupts lysosomes. Immunofluorescence microscopy studies indicate no colocalization of the 78 kDa receptor with the mannose 6-phosphate receptor or LIMPII. Mannose 6-phosphate-independent endocytosed beta-glucuronidase was found in the lysosomal, the early and late endosomal fractions. These fractions were immunoadsorbed in columns containing antibodies against the 78 kDa receptor. Only the endocytosed beta-glucuronidase present in the early and late endosomal fractions is associated to immunoadsorbed vesicles. In these vesicles, LAMP2 was detected but no LIMPII or the mannose 6-phosphate receptor. Results obtained suggest that the 78 kDa receptor is found along the endocytic pathway, but in vesicles different from the cation-independent mannose 6-phosphate receptor.
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PMID:Cation-independent mannose 6-phosphate and 78 kDa receptors for lysosomal enzyme targeting are located in different cell compartments. 1608 51

Lysosomal changes of mouse skeletal muscle during the repair of exercise injuries were studied with biochemical, histochemical, and electron microscopic methods. Treadmill running for 4 hours and 9 hours increased the activities of cathepsin C and beta-glucuronidase, but not that of beta-glycerophosphatase in mouse quadriceps femoris muscle. The highest activities occurred 3 days after exertion and were higher after the longer duration of exertion. Similar changes that were highly correlated with the activities of lysosomal enzymes occurred in the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase and in the concentration of DNA. The activities of lysosomal enzymes correlated significantly with the severity of histopathologic injuries. Histochemical stainings of beta-N-acetylglucosaminidase and beta-glucuronidase showed a strong increase in the staining intensity 3 and 5 days after exertion, both in inflammatory phagocytes and in surviving muscle fibers in the injured area, and staining intensities increased in parallel with the severity of injuries. Electron microscopy showed an increased number of autophagic vacuoles, lysosome-like bodies, and Golgi complexes in the fibers adjacent to necrotic foci, coinciding with the highest histochemical staining pattern. Lysosomal changes in surviving muscle fibers in close proximity to injured muscle fibers could, by autophagic degradation, provide structural elements for the regeneration of injured muscle fibers.
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PMID:Lysosomal changes in mouse skeletal muscle during the repair of exercise injuries. 1675 92

A number of studies, mostly performed ex vivo, suggest that lysosomes are involved in apoptosis as a result of a release of their cathepsins into the cytosol. These enzymes could then contribute to the permeabilization of the outer mitochondrial membrane; they could also activate effector caspases. The present study aims at testing whether the membrane of liver lysosomes is disrupted during Fas-mediated cell death of hepatocytes in vivo, a process implicated in several liver pathologies. Apoptosis was induced by injecting mice with aFas (anti-Fas antibody). The state of lysosomes was assessed by determining the proportion of lysosomal enzymes (beta-galactosidase, beta-glucuronidase, cathepsin C and cathepsin B) present in homogenate supernatants, devoid of intact lysosomes, and by analysing the behaviour in differential and isopycnic centrifugation of beta-galactosidase. Apoptosis was monitored by measuring caspase 3 activity (DEVDase) and the release of sulfite cytochrome c reductase, an enzyme located in the mitochondrial intermembrane space. Results show that an injection of 10 microg of aFas causes a rapid and large increase in DEVDase activity and in unsedimentable sulfite cytochrome c reductase. This modifies neither the proportion of unsedimentable lysosomal enzyme in the homogenates nor the behaviour of lysosomes in centrifugation. Experiments performed with a lower dose of aFas (5 microg) indicate that unsedimentable lysosomal hydrolase activity increases in the homogenate after injection but with a marked delay with respect to the increase in DEVDase activity and in unsedimentable sulfite cytochrome c reductase. Comparative experiments ex vivo performed with Jurkat cells show an increase in unsedimentable lysosomal hydrolases, but much later than caspase 3 activation, and a release of dipeptidyl peptidase III and DEVDase into culture medium. It is proposed that the weakening of lysosomes observed after aFas treatment in vivo and ex vivo results from a necrotic process that takes place late after initiation of apoptosis.
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PMID:Lysosomes and Fas-mediated liver cell death. 1712 11


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