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:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

New nephron anlages appear in the renal cortex up to the 4th postnatal day (PD). The last anlages to be formed develop into functional nephrons by PD 10, and the cortex appears mature at PD 12 after formation of the cortex corticis. The renal medulla develops by the longitudinal growth of loops of Henle and collecting ducts. The immature medulla cannot be divided into different zones and corresponds structurally to the later inner stripe of the outer zone. The inner zone is formed by PD 8, and the outer stripe of the outer zone by PD 12. The renal medulla is mature at PD 21. From the start of its development, the renal proximal tubule consists of the pars convoluta and pars recta. In both parts the formation of the brush border is accompanied by the simultaneous appearance of brush border enzymes (alkaline phosphatase, gamma-glutamyltranspeptidase, dipeptidylaminopeptidase IV) and lysosomal enzymes (acid phosphatase, acid beta-galactosidase, N-acetylglucosaminidase, dipeptidylaminopeptidase II) over the full length of the proximal tubule. During the course of proximal tubule maturation, however, the lysosomal enzyme activities decline in the pass convoluta (with constant brush border enzyme activities), while the brush border enzyme activities increase in the pars recta (with constant lysosomal enzyme activities). The two parts further differ in that they exhibit different lysosomal patterns from the outset, the pars convoluta containing numerous large, highly enzyme-active lysosomes arranged in groups, and the pars recta containing only a few very small lysosomes with low enzyme activity. Thus, even in the newborn rat, the lysosomal pattern of the pars recta already corresponds to that of the mature S3 segment. The S1 and S2 segments of the pars convoluta first differentiate between PD 10 and 21, as the groups of large lysosomes are progressively broken up and the extent of the lysosomal apparatus is diminished, this proceeding in a retrograde direction from the end of the immature pars convoluta.
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PMID:The postnatal development of the rat kidney, with special reference to the chemodifferentiation of the proximal tubule. 732 46

Various enzymatic urinary activities have been proposed to assess renal proximal tubule damage in children, including neonates. Nevertheless comprehensive knowledge on the developmental aspects of physiological enzymuria is limited, particularly with regard to lysosomal and brush border enzymuria. Urinary activities of two lysosomal enzymes, N-acetyl-beta-D-glucosaminidase (NAG) and beta-galactosidase (GAL), and of two brush border enzymes, alanine aminopeptidase (AAG) and gamma-glutamyltransferase (GGT) were comparatively investigated in normal prematures (n = 28), term neonates (n = 52), infants aged less than 2 years (n = 19) and children (n = 33), and compared to urinary excretion of beta 2-microglobulin (B2M). Enzymatic activities were assayed using either spectrophotometrical (NAG, AAP, GGT) fluorimetrical (GAL) or radioimmunological (B2M) methods, and were related to urinary creatinine excretion. Developmental profiles of both the studied lysosomal enzymes and of B2M were similarly characterized with significantly decreasing values from prematures (NAG 9.29 +/- 1.44, GAL 2.26 +/- 0.26 IU/mmol creatinine, indicated as mean +/- SEM) to term neonates (6,94 +/- 0.58 and 1.76 +/- 0.15 IU/mmol creatinine, respectively) and older infants and children. Lysosomal enzymatic urinary activities correlated linearly with a coefficient of r = 0.75, (p < 0.05), while correlations between each lysosomal enzymatic activity and B2M urinary excretion were weaker.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Specific developmental profiles of lysosomal and brush border enzymuria in the human. 772 20

We have investigated the differentiation potential of propagable cultured rat pancreatic duct epithelial cells after in vivo implantation in isogeneic Fischer-344 rats. Cells genetically labeled with Escherichia coli beta-galactosidase (lacZ) reporter gene were embedded in a mixture of collagen and Matrigel (basement membrane matrix) and implanted either subcutaneously or intraperitoneally. Tissues from the two locations were harvested 4 to 8 weeks later. The great majority of the lacZ-labeled epithelial cells colonizing both sites phenotypically resembled hepatocytes, although they demonstrated different degrees of hepatocytic differentiation. Less than 5% of lacZ-labeled cells formed ductular structures. The hepatocyte-like cells from the subcutaneous implantation site expressed mixed phenotypes of both hepatocyte and ductal cell, including the expression of alpha-fetoprotein, tyrosine amino-transferase, gamma-glutamyl transpeptidase, carbonic anhydrase II, and cytokeratin 19. In contrast, the hepatocyte-like cells colonizing the mesentery showed the phenotype of mature hepatocytes, including an abundant glycogen storage and a lack of alpha-fetoprotein and carbonic anhydrase II expressions. Neither acinar cell nor endocrine differentiation was seen. These findings demonstrate that pancreatic ductal cells can be the progenitor cell for transdifferentiated hepatocytes.
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PMID:Hepatocytic differentiation of cultured rat pancreatic ductal epithelial cells after in vivo implantation. 767 82

Alterations in the metabolic functions of trabecular meshwork (TM) cells are thought to be involved in the pathogenesis of primary open-angle glaucoma (POAG). In an investigation of this possibility, 30 trabeculectomy specimens from patients with POAG were examined histochemically for 11 lysosomal and membrane-bound enzymes. The patients ranged from 48 to 87 years in age. The degree of enzyme staining was compared with that of 15 age-matched controls obtained from an eye bank at less than 24 h after death. There was no history of eye disease in the controls. The enzymes examined were: dipeptidylpeptidases II and IV (DPPII and IV); beta-glucuronidase (beta-GLUC); acid-beta-galactosidase (s beta-GAL); N-acetyl-beta-D-glucosaminidase (NAG); nonspecific esterase (UE); acid phosphatase (SP); alkaline phosphatase (ALP); gamma-glutamyltransferase (GGT); and aminopeptidase A and M (APA and APM). Evaluation of the specimens was performed by two observers and by computer-aided optic densitometry. Results showed increased staining of SP, UE, GGT and APM in the pathological specimens as compared with the controls. SP and UE indicate phagocytic activity, APM is involved in collagen turnover and GGT participates in both drug detoxification and the breakdown of glutathione in the gamma-glutamyl cycle. Our observations show different hydrolase activities in the TM cells of human glaucomatous eyes as compared with normal values, suggesting that such metabolic differences may be related to the pathogenesis of POAG.
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PMID:Increased hydrolase activities in the human trabecular meshwork of glaucomatous eyes. 809 35

The distributions of the hydrolases acid and alkaline phosphatase (AP and ALP), N-acetyl-beta-D-glucosaminidase (NAG), beta-glucuronidase (beta-Gluc), beta-galactosidase (beta-Gal), non-specific esterase (UE), dipeptidylpeptidases II and IV (DPPII and DPPIV), aminopeptidases M and A (APM and APA), and gamma-glutamyltransferase (GGT) were investigated in the human, pig and Lewis rat normal anterior segment by histochemical methods. The distribution of the above hydrolases, particularly that of proteases, varied between ocular tissues and between the three species. Lysosomal hydrolases together with GGT and ALP were consistently active in the corneal epithelium, stroma and endothelium in all three species; the corneal distribution and activity of beta-Gal, APM, APA and DPPIV, however, displayed interspecies variation. The angular tissues showed similarities for most hydrolases with the exceptions of beta-Gal, UE, APM, APA and DPPIV. In all eyes examined strong ciliary epithelial activity for AP, beta-Gal, UE, GGT and ALP was observed in the pars plicata; only the pig eye also displayed strong DPPIV activity in this area. Regional differences in hydrolase distribution in the iris were observed in all species. A post-mortem freezing delay of longer than 24 h resulted in a decrease in hydrolase activity.
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PMID:Hydrolases of anterior segment tissues in the normal human, pig and rat eye: a comparative study. 818 69

The distributions of the lysosomal enzymes [acid phosphatase (AP), N-acetyl-beta-D-glucosaminidase (NAG), beta-glucuronidase (beta-Gluc), beta-galactosidase (beta-Gal), dipeptidylpeptidase II (DPP II)] and of the membrane-bound proteases [aminopeptidase M (APM), aminopeptidase A (APA), gamma-glutamyltransferase (GGT), dipeptidylpeptidase IV (DPP IV)] were investigated in the normal human adult and foetal anterior segment by histochemical methods. The distribution of these hydrolases varied between ocular tissues. The most active enzymes in the adult corneal epithelium and endothelium were AP, beta-Gluc, NAG, beta-Gal and GGT; in the keratocytes, APM, APA, beta-Gluc and GGT predominated. The adult trabecular meshwork cells were stained by AP, beta-Gluc, NAG, APM, GGT, DPP II and DPP IV. The enzymes AP, beta-Gluc, APM and APA, however, displayed greater activity in the endothelium of Schlemm's canal. The adult ciliary epithelium stained strongly for all lysosomal hydrolases; GGT was the most active protease here. Differences in enzyme activity were noted in some tissues when foetal and adult anterior segments were compared. There appeared to be a decrease in the activity of some enzymes with age and post-mortem delay greater than 24 h. The function(s) of each enzyme and their possible roles in the respective tissues are discussed.
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PMID:Histochemical survey of the anterior segment of the normal human foetal and adult eye. 822 58

To examine the postnatal development of equine small intestine, biopsy specimens of jejunal mucosa from 8 ponies, between 6 and 28 weeks old, were subjected to analytical subcellular fractionation and assay of organelle marker enzymes. Fractionation revealed a reduction in the particulate brush border component of beta-galactosidase (lactase) activity between 6 and 28 weeks, and a corresponding increase in soluble activity, although the reduction in mean specific activity was not significant. There also was a decrease in the proportion of brush border to soluble aminopeptidase N activity, a relative loss of brush border gamma-glutamyltransferase activity, and a considerable decrease in the specific activity of alkaline phosphatase throughout the gradient fractions. In contrast, there were marked increases in activities of alpha-glucosidase (maltase) and sucrase in the older ponies, accompanied by considerable changes in the intracellular distribution of particulate alpha-glucosidase activity, which was predominantly associated with endoplasmic reticulum at 6 weeks, whereas the large increase in activity observed by 28 weeks was clearly associated with the brush border. The modal density of brush borders also increased with age, suggestive of an increase in the glycoprotein-to-lipid ratio of the microvillar membrane. In contrast to these brush border changes, there was relatively little alteration in the activities or density distributions of marker enzymes for endoplasmic reticulum, basolateral membranes, mitochondria, or lysosomes. These findings indicate that maturation of equine intestinal epithelium during the first few months of life results in major changes in the properties and enzyme composition of enterocyte brush borders.
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PMID:Subcellular biochemical changes during the development of the small intestine of pony foals. 853 83

Advances in liver surgery and transplantation have lead to a steady increase in the number of these interventions. Prompt quantitative assessment of hepatic of hepatic function and a patient's subsequent morbidity and mortality following surgery remain difficult despite the currently utilized historic markers of hepatic parenchymal injury (e.g., aspartate transaminase [AST], lactate dehydrogenase [LDH] gamma-glutamyl transpeptidase [GGT]). Increases in serum glycohydrolase activities appear to provide sensitive and quantitative markers of hepatic ischemia/reperfusion injury. In 10 male swine (25 to 35 kg body weight) following 30, 45, and 90 minutes of acute hepatic ischemia, the systemic release of eight different glycohydrolases and lipid peroxides into serum were determined and compared with pre- and postischemic serum levels of LDH, GGT, and AST. The rapid release of glycohydrolases into serum was directly proportional to the length of the ischemic period from 30 to 90 minutes; e.g., beta-glucosidase, mean 1.9-fold increase at 30 minutes; 8.3-fold at 45 minutes; and 22.8-fold at 90 minutes; P < .002) and the activities peaked within the first 3 hours postischemia. In constrast, AST, LDH, and GGT were released slowly and peaked 20 to 30 hours after hepatic blood flow was restored. In swine with fatal outcomes (90 minutes of ischemia), all enzyme levels increased continuously during the final hours of life. However, in swine that survived hepatic ischemia/reperfusion injury (45 minutes of ischemia) the glycohydrolases, but not AST, LDH, and GGT, declined after 2 to 3 hours' postischemia and the serum lipid peroxide levels followed the same pattern. Serum beta-galactosidase and beta-glucosidase levels are sensitive markers that rise as quickly as traditional enzyme markers (AST, LDH, GGT) following hepatic ischemic injury; moreover, the glycohydrolases have the added value of serving as predictors of survival.
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PMID:Glycohydrolases as markers of hepatic ischemia-reperfusion injury and recovery. 870 56

Evidence for temporal variations in the nephrotoxicity of low doses of aminoglycosides were recently shown by using specific and sensitive parameters of renal toxicity. The aim of the present study was to evaluate the effect of a short period of fasting on the temporal variations in the renal toxicity of gentamicin. Twenty-eight normally fed (i.e., food and water were available ad libitum throughout the experiment) female Sprague-Dawley rats (weight, 175 to 220 g) and 28 fasted rats (i.e., only water was available during a 12-h fast before and a 24-h fast after gentamicin injection) were used. The animals were synchronized on a 14-h light, 10-h dark cycle (lights on at 0600 h) for 1 week before gentamicin administration. In July 1993, each group of animals was treated with a single intraperitoneal injection of saline (NaCl, 0.9%) or gentamicin (150 mg/kg of body weight) at either the peak (1400 h) or the trough (0200 h) of the previously determined toxicity. On day 1, the 24-h urinary excretion of beta-galactosidase, N-acetyl-beta-D-glucosaminidase, and gamma-glutamyltransferase was significantly higher in normally fed animals treated with gentamicin at 1400 h than in their time-matched controls and in normally fed animals treated at 0200 h (P < 0.01), which had normal levels of these enzymes. By contrast, the urinary excretion of these enzymes was significantly higher in both groups of gentamicin-treated, fasted rats than in their time-matched control groups (P < 0.01), reaching levels similar to those measured in normally fed rats treated at 1400 h. The accumulation of gentamicin was significantly lower in the renal cortex of normally fed rats treated at 0200 h than in rats treated at 1400 h (P < 0.05), but this time-dependent difference was not found in fasted rats treated at 0200 and 1400 h. Immunogold labeling done on ultrathin sections and observed by electron microscopy showed a similar subcellular localization of gentamicin in normally fed and fasted rats treated at either 1400 or 0200 h. These results suggest that the feeding period is of crucial importance in the temporal variations of the nephrotoxicity of gentamicin in rats.
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PMID:Effects of fasting on temporal variations in nephrotoxicity of gentamicin in rats. 885 91

Transglutaminase (protein-glutamine: amine gamma-glutamyltransferase, EC 2.3.2.13) from Streptoverticillium mobaraense has been used to stabilize immobilisates produced with beta-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) from Aspergillus oryzae and acid-processed gelatins of different qualities as support. The isopeptide level of N epsilon-(gamma-L-glutamyl)-L-lysine bonds formed by transglutaminase was determined to estimate their influence on the kinetic properties of the enclosed beta-galactosidase. An HPLC procedure using precolumn derivatization of the gelatin hydrolysates with FMOC-chloride was chosen which permits the analysis of cross-linked lysine with satisfactory precision. Depending on the gelatin quality, the degree of cross-links necessary for the transformation of gelatin into an insoluble protein was in the range 0.3-32.3% of the available lysine residues. beta-Galactosidase was entrapped in the gelatin matrices with a yield of 8-46% of the initial activity. Long reaction times for cross-linking were due to low yields rather than to the number of isopeptide bonds. Repeated use of the immobilisates did not lead to an appreciable loss of activity. The Vmax of beta-galactosidase were diminished by immobilization caused by a tighter package of the protein chains rather than by the extent of cross-links, while the obtained Km values of the free enzyme and the immobilisates were quite similar. Also, the pH and temperature of optima of the free enzyme and the gelatin immobilisates differ only slightly. The data suggest that the immobilization procedure only moderately affects the activity of enzymes catalysing the reaction of a small compound if gelatin with high jelly strength is cross-linked in a 10% solution with transglutaminase.
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PMID:Influence of gelatin matrices cross-linked with transglutaminase on the properties of an enclosed bioactive material using beta-galactosidase as model system. 885 18


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