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)

Changes in activities of a new proteinase cathepsin T as well as some other lysosomal acid proteinases and hydrolases were examined in liver homogenate from rats treated with a single hepatotoxic dose of carbon tetrachloride. The most striking changes were several-fold increases of liver cathepsin T and D activities over their levels in untreated rats 3 days after administration of the agent to rats. Increase of cathepsin T was greater than that of cathepsin D at all doses of the hepatotoxin examined. The activities of N alpha-benzoyl-DL-arginine 2-naphthylamide hydrolase, acid phosphatase, beta-galactosidase and beta-glucuronidase in poisoned rat liver were unchanged or only slightly increased. Cathepsin T and D activities were less enhanced in mitochondrial lysosomal fractions than in the homogenate, and were greatly elevated in the supernatant fractions of liver from the treated rats. As judged from the molecular weights, the elevated activities of cathepsins T and D in the treated rat liver could be attributable to the two cathepsins themselves and not to other proteinases. Administration to rats of other hepatotoxic agents, thioacetamide and dimethylnitrosamine, also induced the elevation of the two cathepsin activities in liver, but on partial hepatectomy the activities of liver cathepsins T and D did not show such marked increases. Nonparenchymal liver cell fractions were responsible for almost all the increased activities of liver cathepsins T and D. It is possible that cathepsins T and D play a role in the heterolytic breakdown of hepatocyte molecules following CCl4 poisoning.
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PMID:Increased activities of liver cathepsins T and D in carbon tetrachloride-treated rats. 649 24

An inhibitor of lysosomal acid cholesteryl ester hydrolase (Acid CEH), (EC 3.1.1.13) was found in the cytosolic fraction of rat liver and various other tissues. The extent of the inhibitory effect was dependent on the concentration of the cytosolic protein. The Acid CEH inhibitor was heat-labile, non-dialyzable, and its inhibitory activity significantly decreased by trypsin or chymotrypsin digestion, but not by lipase digestion. The inhibitor had no effect on the activity of cathepsin D, beta-glucuronidase and acid phosphatase, which are other enzymes found in lysosomes. The present findings suggest that the inhibitor may be involved in the regulation of the hydrolysis of cholesteryl esters in lipoproteins that have been transferred into the liver.
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PMID:Characterization of a cytosolic protein inhibiting lysosomal acid cholesteryl ester hydrolase. 650 18

The activities per microgram DNA of five lysosomal enzymes [cathepsin D, cathepsin B, beta-N-acetylglucosaminidase (beta-NAG), beta-glucuronidase, and acid phosphatase] were measured in homogenates of female and male rat (Sprague-Dawley) hearts. Female rats were studied during stages of the estrous cycle and at 3 weeks after ovariectomy. Three-week-postovariectomized female rats and intact male rats were injected subcutaneously with 17 beta-estradiol-3-benzoate. Lysosomal enzyme activities in the male rat heart were more responsive to exogenous estradiol than were activities in the female rat heart. Cathepsin B, beta-NAG, and beta-glucuronidase were increased dramatically in the male rat heart upon short-term administration of estrogen (4 days). In both female and male rat hearts, activities of two lysosomal proteinases, cathepsins B and D, were reduced significantly (approximately 50%) by extended administration of estrogen for 10 days.
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PMID:Effect of estrogen on lysosomal enzyme activities in rat heart. 651 19

Male rats were maintained for periods of up to 16 weeks on a fat free diet which was supplemented with either 4% tripalmitin (essential fatty acid [EFA] deficient) or with 4% safflower oil (SAFF, control). Pulmonary alveolar macrophages (PAM) were obtained by lung lavage. PAM from EFA deficient rats had reduced phagocytic activity and capacity. Intracellular killing of ingested yeast was also reduced by EFA deficiency. The activity of acid phosphatase, beta-glucuronidase and cathepsin D from PAM was not altered by dietary treatment. Transmission electron microscopy failed to show any consistent morphologic differences between PAM from EFA deficient and SAFF animals, but did confirm the decreased phagocytosis by PAM from EFA deficient rats. However, scanning electron microscopy did show loss of pseudopodia in PAM from EFA deficient rats. EFA deficiency was demonstrated by analyzing the methyl esters of the fatty aids from the total lipid extract of PAM. The arachidonate content was decreased while the eicosatrienoate content was increased in PAM derived from rats fed the EFA deficient diet. In an effort to elucidate further the mechanism of action of EFA deficiency in impairing phagocytosis by PAM, inhibitors of various reactions which lead to oxygenated derivatives of arachidonate were studied using PAM from chow fed rats. Some of these inhibitors were effective in diminishing phagocytosis. Furthermore, PAM from these preparations when fixed in suspension and examined with scanning electron microscopy showed morphological changes similar to those seen in EFA deficiency. This similarity of surface ultrastructural changes suggests that EFA deficiency may impair phagocytic function of PAM by reducing availability of an oxygenated derivative of arachidonic acid.
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PMID:The effects of essential fatty acid deficiency on pulmonary alveolar macrophage function. 653 82

Modifications in the activities of some lysosomal enzymes were studied in the small intestine after irradiation on the abdomen by multiple daily fractionation of 3 Gy per fraction every 12 hours. Total doses of 6 and 12 Gy were studied. With lower dose variations were slight. The modifications of acid phosphatase an cathepsin D appeared very low, whereas beta-glucuronidase increased until 72 hours after the last fraction and then returned to control values. With respect to 8 Gy single dose the injury appeared comparatively similar.
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PMID:Behaviour of lysosomal enzymes in the small intestine after multiple daily fractionation. 662 64

The activities of beta-glucuronidase and cathepsin D and the protein concentration were assayed from brain, kidney, liver, cardiac muscle and skeletal muscle (m. rectus femoris) samples from mice (Mus musculus) 1, 3, and 6 days after intermittent exhaustive (duration 100-145 min) and submaximal prolonged (duration 9 hr) running on treadmill. The activity of beta-glucuronidase in skeletal muscle strongly increased being the highest 3 days after both exertions. Cathepsin D activity also slightly increased. In cardiac muscle beta-glucuronidase activity was unaffected. Cathepsin D activity slightly increased 3 days after intermittent exhaustive exercise. The specific activities of beta-glucuronidase and cathepsin D in the liver increased 1 day after the both exertions. Simultaneously the protein concentration decreased. In the kidney beta-glucuronidase activity and protein concentration were unaffected but cathepsin D activity decreased 1 day after intermittent exhaustive exercise. In the brain protein concentration transiently decreased 3 days after the exertions. beta-Glucuronidase activity transiently decreased 1 day after intermittent exercise thereafter increasing 6 days afterwards above the control level. Cathepsin D activity decreased 1 day after intermittent exercise but was unaffected after prolonged submaximal exercise. Physical stress affected to varying extent the acid hydrolase activities in all organs studied.
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PMID:Acid hydrolase activity in tissues of mice after physical stress. 664 Nov 64

Chloroquine-resistant (CQr) clones (CQ-21 and CQ-22) have been isolated from mutagenized hamster lung V79 cells by exposing the cells to a high dose of chloroquine. CQ-21 and CQ-22 showed about 3-fold higher resistance to chloroquine than the parental V79 cells, and they showed specific cross-resistance to another amine, NH4Cl, which is also concentrated in lysosomes. CQr clone showed no cross-resistance to other unrelated agents. Chloroquine-induced inhibition of [125I]ricin internalization was observed in both cell lines at neutral pH, but the inhibition of uptake was less in the variant. Also, the degradation of endogenous protein was slowed in the mutant; further, treatment of cells with 30 micrograms/ml of chloroquine inhibited the degradation of endogenous proteins in the parental V79, but not in CQ-22 cells. Similar levels of acid phosphatase, beta-glucuronidase and cathepsin D were observed in V79 and CQ-22 cells, but the level of cathepsin B was lower in the mutant. Electron microscopy showed an increased number of electron-dense bodies, possibly autophagosomes/lysosomes, in the mutant cells grown for 4 days with 5 micrograms/ml of chloroquine. Similar aberrant structures were observed in the parental V79 cells treated for only 3 h with 5 micrograms/ml of chloroquine.
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PMID:Isolation of chloroquine-resistant Chinese hamster V79 cell variants that are also resistant to ammonium chloride. 665 68

Immunoelectron microscopic localization of lysosomal and peroxisomal enzymes in the eosinophil leukocytes of rat intestinal mucosa was studied by use of rabbit antibodies to the enzymes coupled to protein A-gold complex. Gold particle labeling for the lysosomal enzymes, beta-glucuronidase and cathepsin D, was present on specific granules, with a heavy concentration on their paracrystalline cores. The peroxisomal enzymes, acyl-CoA oxidase and catalase, were also found on these granules. The double labeling procedures using two different combination of anti-acyl-CoA oxidase and anti-beta-glucuronidase or anti-catalase and anti-cathepsin D revealed that these enzymes were simultaneously present in specific granules of the intestinal eosinophils. Quantitative analysis of the labeling on subcellular compartments confirmed that all enzymes examined are significantly localized within specific granules and that there is no significant labeling on other compartments such as the nucleus and cytoplasm. In the control sections incubated with an immunoglobulin G fraction from nonimmunized rabbits, no specific labeling was seen on the granules or other organelles. These findings indicate that enzymes which previously have been identified in some organs as lysosomal and in others as peroxisomal can be found together in eosinophil granules.
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PMID:Localization of lysosomal and peroxisomal enzymes in the specific granules of rat intestinal eosinophil leukocytes revealed by immunoelectron microscopic techniques. 669 57

Three experiments were designed to study the lysosomal changes associated with the development and maintenance of the endurance training induced resistance against exercise injuries in mouse skeletal muscles. The activities of arylsulphatase, cathepsin C, cathepsin D, and beta-glucuronidase were assayed from the red part of mouse quadriceps femoris muscle 4 days after prolonged strenuous running of 4-9 h duration. Exercise injuries were characterized by necrotic fibers and focal inflammation. Strenuous running of untrained mice induced necrotic lesions and a 4-5 fold increase in the activities of lysosomal enzymes. This lysosomal response was considerably reduced already by daily training bouts on the 3 days preceding the strenuous exertion. Simultaneously exercise injuries were markedly reduced. Extending the endurance training program increased the running ability of mice and further reduced the necrotic lesions and lysosomal changes induced by the strenuous exercise. The detraining of 1 week after the termination of regular endurance training considerably increased the degree of exercise induced lysosomal response. The detraining of longer durations further increased the lysosomal response and no effect of prior endurance training existed after 1 month detraining. Our observations suggest that the severity of exercise injuries is related to the strength of the exercise stimulus and the level of preceding physical activity and can be characterized by the lysosomal changes.
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PMID:Lysosomal changes related to exercise injuries and training-induced protection in mouse skeletal muscle. 672 Mar 24

Mice with generalized influenza or tularemia of similar lethality were studied in an effort to compare biochemical responses of the myocardium during infections of viral and bacterial etiology. A progressive loss of body weight characterized the course of both infections. Accompanying this, the myocardial content of protein and the activities of lactate dehydrogenase, citrate synthase, and cytochrome c oxidase all decreased. However, myocardial protein degradation appeared earlier and was more pronounced in influenza, and the protein changes were accompanied by a rapid decline of myocardial RNA. Activation of acid hydrolases, such as cathepsin D and beta-glucuronidase, occurred in tularemia but not in influenza, whereas leakage of beta-glucuronidase into the plasma occurred in both infections. Conversely, there was a considerably greater activation of myocardial catalase in influenza. These findings suggested that different control mechanisms or metabolic pathways were operative in the degradation of myocardial constituents in influenza as compared with tularemia. The absence of histological signs of myocarditis in either infection appeared to exclude any direct local effects of an inflammatory process on myocardial cells. Since the infections were of comparable lethality (based upon the inoculated dose of organisms), the observed differences in pattern and extent of metabolic responses of the myocardium to these infections may be attributed to different pathophysiological mechanisms evoked by the different microorganisms.
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PMID:Sequential metabolic alterations in the myocardium during influenza and tularemia in mice. 674 1


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