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)

Renal toxicity of aminoglycosides seems to be less frequent in newborn infants compared to adults even though glomerular filtration rate and tubular secretion and reabsorption mechanisms are subjected to adaptive processes during the neonatal period. In 14 infants, kinetic parameters of gentamicin were determined using an open three-compartment body model. According to the lower glomerular filtration rate, the beta-elimination phase is longer in the newborn infant compared to adults, while the gamma-elimination phase is quite similar to adult values. The calculated drug accumulation in the deep compartment (kidney) under steady-state conditions is lower in newborns compared to infants. The excretion of urinary enzymes of tubular origin, that is the lysosomal NAG (N-acetyl-beta-D-glucosaminidase), beta-glucuronidase, and the brush-border-associated AAP (alanine-aminopeptidase), GGT (gamma-glutamyl-transpeptidase), are lower in healthy newborn infants compared to older ones. The increase of AAP, for instance, during aminoglycoside therapy is less pronounced in newborn infants, especially in prematures, if compared to adult values. After end of therapy the AAP excretion decreases to normal. The calculated rate of this decrease takes place in a fashion similar to the release of drugs from the kidney (gamma-elimination phase). The data indicate that there may be a lower renal accumulation of aminoglycosides in newborn infants, which can be explained by the morphometric and functional characteristics of the newborn kidney.
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PMID:Renal toxicity of aminoglycosides in the neonatal period. 614 23

An ionic (diatrizoate) and a non ionic (iopamidole) radiocontrast medium were compared as to their nephrotoxicity in a cohort of 21 patients with renal disease, 18 of which with normal renal function. The elevation of the urinary excretion of enzymes from renal tubular cells has been considered as a good index for renal tubular damage. We measured two lysosomal enzymes (NAG and beta glucuronidase) and a brush-border enzyme (gamma GT). In all patients we demonstrated an elevation of urinary excretion of the three enzymes already 12 hours after contrast medium administration. However, the elevation was statistically significant only after employment of the ionic contrast medium and concerned gamma GT and beta-glucuronidase; the urinary excretion of NAG did not vary significantly. Urinary enzymes levels returned to basal values 36 hours after intravenous pyelography. In conclusion, iopamidole showed a lower nephrotoxicity with respect to diatrizoate, as demonstrated by the lower levels of urinary enzymes excretion reached after its use.
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PMID:[Nephrotoxicity of contrast media. Comparison of iopamidol and diatrizoate by measurement of urinary enzymes after urography]. 615 May 20

The serum activities of two lysosomal enzymes, beta-N-acetylglucosaminidase (EC 3.2.1.30; NAG) and beta-glucuronidase (EC 3.2.1.31; GLU) were analysed in 116 male patients with silicosis. Twenty-eight of the patients were matched with controls of similar sex, age and exposure to silica dust but with no radiographical evidence of silicosis. A control group which had not been exposed to silica dust consisted of male blood donors. The mean activity of NAG in serum was higher in the silicosis patients than in the blood donors (P less than 0.01). Similarly, the NAG level in the silicosis patients with matched controls was higher than that in the silica-exposed controls (P less than 0.05). The silicosis patients who showed a progression of small opacities by one or more subcategories had a slightly higher mean NAG activity in their sera than the patients with no progression but this difference did not reach statistical significance; the activity was higher than in silica-exposed controls (P less than 0.05). We suggest that these findings may be related to the effects of silica on macrophages which have been observed experimentally in vitro and in vivo and might indicate an increased turnover of macrophages caused by silica dust and active, progressive silicotic fibrosis.
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PMID:Serum beta-N-acetylglucosaminidase and beta-glucuronidase activities in silicosis patients and in workers exposed to silica dust. 633 85

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

Ligatin, a receptor that recognizes phosphorylated sugars, was isolated from plasma membranes of mouse macrophages, rat ileum, and rat brain. Several acidic hydrolases including N-acetyl beta-D-glucosaminidase (beta-NAG) were solubilized with this receptor. The solubilized beta-NAG bound to ligatin in vitro as demonstrated by affinity chromatography using the immobilized receptor. beta-N-Acetyl D-glucosaminidase-ligatin complexes were dissociated by low concentrations of mannose 6-phosphate (Man6P) and/or glucose 1-phosphate (Glc 1P). The effectiveness of these two phosphomonosaccharides varied depending on the source of the enzyme: ileal beta-NAG-ligatin complexes showed a four-fold preferential dissociation with Man6P; macrophage complexes showed a 160-fold preferential dissociation with Glc 1P. Brain complexes dissociated with nearly equal preference for Man6P and Glc 1P. Heterologous complexes displayed the specificity characteristic of the source of the enzyme regardless of the source of the ligatin. Treatment of the solubilized hydrolases with endoglucosaminidase H released phosphorous-32 label from these enzymes and prevented binding of beta-NAG to ligatin. However, treatment of the solubilized hydrolases with alkaline phosphatase reduced the binding of beta-NAG to ligatin by no more than 30%. This apparent resistance of beta-NAG to dephosphorylation was consistent with the chromatographic behavior of QAE of 3H-labeled acidic oligosaccharides isolated from the solubilized hydrolases. The oligosaccharides that contain phosphorylated hexose were less acidic than phosphomonoesters and were insensitive to alkaline phosphatase until subjected to acid hydrolysis. These results suggested the presence of a phosphodiester on beta-NAG analogous to the NAC glucosamine 1 P6 mannose present on beta-glucuronidase isolated from mouse lymphoma cells (Tabas I, Kornfield, S: J Biol Chem 255: 6633, 1980).
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PMID:Ligatin binds phosphohexose residues on acidic hydrolases. 729 41

The serum activities of two lysosomal enzymes, beta-N-acetylglucosaminidase (EC 3.2.1.30, NAG) and beta-glucuronidase (EC 3.2.1.31, GLU), were determined in 41 insulin-dependent diabetics, 27 age-matched non-diabetic first-degree relatives of the diabetics and 103 age-matched non-diabetic blood-donors. The diabetics were divided into three groups on the basis of ophthalmoscopy: (1) no retinal abnormalities; (2) non-proliferative retinopathy; and (3) proliferative retinopathy. The activities of both serum enzymes were higher in diabetics (NAG 21.39 +/- 5.99; GLU 2.19 +/- 1.01) than in their relatives (NAG 17.22 +/- 3.99; GLU 1.62 +/-0.61). The diabetics with non-proliferative retinopathy had higher serum enzyme levels (NAG 24.05 +/- 6.26; GLU 2.60 +/- 1.06) than diabetics without retinopathy (NAG 17.88 +/- 3.00; GLU 1.69 +/ 0.64), whereas no statistically significant difference was found in patients with the proliferative form of retinopathy (NAG 18.67 +/- 6.28; GLU 1.99 +/- 1.04). In diabetics a positive correlation was found between serum beta-N-acetylglucosaminidase activity and blood glucose (p < 0.01), but not between beta-glucuronidase and blood glucose. Furthermore, the activities of both enzymes in diabetics correlated with the plasma triglyceride level (p < 0.05 for both correlations). No correlation was found between the enzyme levels and signs of other diabetic late complications.
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PMID:beta-N-acetylglucosaminidase and beta-glucuronidase activities in insulin-dependent diabetic subjects with retinopathy. 741 53

Administration of hepatotoxic doses of diquat to male Fischer-344 rats increases biliary excretion of nonheme iron, whereas comparably hepatotoxic doses of acetaminophen decrease biliary export of iron. The effects of acetaminophen and diquat on the activities in bile of representative lysosomal enzymes, beta-N-acetylglucosaminidase (beta-NAG) and beta-glucuronidase (beta-GLUC) were examined as a means of assessing the possible role of lysosomal exocytosis in the effects of these hepatotoxins on biliary excretion of iron. In pentobarbital-anesthetized male Fischer-344 rats, diquat at 0.1 mmol/kg increased the biliary export of biliary beta-NAG and beta-GLUC, in conjunction with similar increases in iron. Sprague-Dawley rats, which are resistant to diquat-induced hepatic necrosis despite showing marked oxidant stress responses, showed no increases in biliary efflux of iron, beta-NAG, or beta-GLUC in response to diquat. Conversely, acetaminophen at doses of 400 or 1500 mg/kg markedly decreased biliary concentrations and efflux rates of beta-NAG and beta-GLUC in Fischer-344 rats in parallel with decreases in biliary iron, suggesting that the hepatotoxin-induced effects on biliary iron excretion may be mediated through effects on lysosomal exocytosis. Both acetaminophen and diquat increased total protein content of bile in both strains of rats; however, the proteins excreted after administration of diquat to Fischer-344 rats showed marked increases in contents of protein carbonyls, as assayed with 2,4-dinitrophenylhydrazine, whereas biliary proteins in acetaminophen-treated animals were not more oxidized than in controls. Sprague-Dawley rats given diquat showed no increase in the biliary excretion of protein carbonyls, despite the increased excretion of glutathione disulfide observed in these animals. The significant increases in biliary excretion of protein carbonyls by the diquat-treated Fischer-344 rats suggest oxidation of cellular proteins catalyzed by chemically reactive iron chelates and the excretion of at least some of the oxidized proteins to the bile, possibly through lysosomal exocytosis. The effects of acetaminophen on biliary protein excretion do not appear to involve oxidation.
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PMID:Biliary excretion of lysosomal enzymes, iron, and oxidized protein in Fischer-344 and Sprague-Dawley rats and the effects of diquat and acetaminophen. 812 94

The mammalian epididymis is an organ particularly rich in acid hydrolases, consistent with a developed lysosomal apparatus. However, some of these enzymes could also play a role in an extracellular environment, since they are actively secreted by the epithelium. In this study the authors measured the activity of five acid hydrolases distributed between the epithelium, fluid, small vesicles, and spermatozoa of the rat cauda epididymis in adult rats, and compared with that distribution under conditions of deprivation of luminal testosterone and testicular compounds (hemicastration). Lysosomal enzymes are differently compartmentalized in rat cauda epididymis. Most of beta-galactosidase (beta-GAL) and aryl sulfatase (approximately 70%) were found in soluble form within the fluid. Some 60% of N-acetyl-beta-D-glucosaminidase (beta-NAG) and alpha-mannosidase (alpha-MAN) become transiently bound to sperm, and beta-glucuronidase (beta-GLU) was mostly concentrated in the epithelium. After remotion of testis this distribution changed, as the retention of alpha-MAN, beta-GAL, beta-GLU, and beta-NAG by the epididiymal tissue increased. The increase of beta-GLU followed an increase of synthesis of the enzyme. The distribution of enzymes in the epididymis from the contralateral side was similar to that in normal rats. The different roles for each enzyme in the epididymis are discussed.
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PMID:Compartmentalization of lysosomal enzymes in cauda epididymis of normal and castrated rats. 1196 12


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