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:3.2.1.20 (alpha-glucosidase)
4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Jejunum of 19-day fetal rats was explanted in organ culture for 48 h in the presence of dexamethasone (DX) and cycloheximide (CX) or actinomycin D (Act D). The concentrations of both inhibitors which provided maximal responses without any detrimental alteration of the tissue were determined. During the culture period, CX (0.5 microgram/ml) totally abolished the production of both DX-stimulated enzymes (sucrase, maltase, lactase) and DX-insensitive enzymes (aminopeptidase, alkaline phosphatase). On the contrary, Act D at 2 micrograms/ml exhibited differential levels of inhibition related to the enzyme considered: 100% for sucrase and aminopeptidase, 70% for maltase and 50% for lactase. By contrast, alkaline phosphatase was stimulated 100% by Act D. These data suggest that the mechanism by which DX induces sucrase and stimulates maltase activity takes place at the transcriptional level. They also indicate that the basic maturation of at least maltase and lactase activities depends upon the traduction of a preexisting pool of mRNAs. The superinduced alkaline phosphatase activity obtained with Act D supports the notion that an Act D-sensitive repressor may play a role in the maturation process of this enzyme.
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PMID:Organ culture of fetal rat intestine. Effects on brush border enzyme activities of the combined administration of dexamethasone and cycloheximide or actinomycin D. 672 12

Jejunal mucosa of 6 d-old rats were cultured for 24 and 48 h in the presence of thyroxine, insulin, pentagastrin, glucagon, epidermal growth factor (EGF) or dibutyryl-A-3:5-MP cyclic with or without dexamethasone (DX). The enzymes were assayed on the purified brush borders. The various agents added alone to the basic culture medium had no effect with the exception of DX on the levels of enzyme activities. Dexamethasone alone induced sucrase, stimulated maltase, and protected other brush border enzyme activities (aminopeptidase, lactase, and alkaline phosphatase). When added to DX-supplemented medium, only the following factors modified the levels of enzymatic activities observed with DX alone. Insulin (10(-6) M) increased maltase, alkaline phosphatase, and lactase activity to a greater extent than DX at 24 h culture, the effect being maintained at 48 h on alkaline phosphatase only. At 48 h culture, both EGF (10(-8) M) and dbcAMP (10(-3) M) decreased DX-induced sucrase activity. The latter agent also depressed DX-stimulated aminopeptidase activity.
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PMID:Organ culture of suckling rat intestine: comparative study of various hormones on brush border enzymes. 674 50

A total of 80 oral strains of Bacteroides gingivalis, B. asaccharolyticus, B. melaninogenicus subsp. intermedius, B. melaninogenicus subsp. melaninogenicus, Capnocytophaga, Treponema denticola, and T. vincentii were characterized with the API ZYM system for 19 enzyme activities. Comparison of anaerobic and aerobic incubation with nine reference strains of these organisms showed no important differences. The key differential tests for black-pigmented Bacteroides strains and treponemes of oral origin were trypsin, alpha-glucosidase, and N-acetyl-beta-glucosaminidase. All Capnocytophaga strains produced distinctive aminopeptidase activities but varied in their glycosidic capabilities. The presence of a trypsin-like activity in B. gingivalis, T. denticola, and a group of Capnocytophaga strains may contribute to tissue destruction in periodontal disease.
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PMID:API ZYM system for identification of Bacteroides spp., Capnocytophaga spp., and spirochetes of oral origin. 676 81

In order to gain more insight into the adaptative mechanism of intestinal enzymes to dietary factors in rats, modifications in the activities of disaccharidases and aminopeptidase were measured after refeeding of a 70% solution of sucrose for 15 h following a 2-day fast. Mature epithelial cells from the villus and immature cells from the crypt were isolated after sequential removal of the cells along the villus-crypt axis. Synthesis of brush border disaccharidases was determined by measuring [3H]valine incorporation into proteins. 1. In the whole mucosa, a highly significant increase in sucrase and maltase activities and a significant drop in aminopeptidase activity was observed in the brush border membranes after sucrose refeeding. 2. Stimulation of sucrase and maltase activities in sucrose refed rats was produced mainly in the immature cells of the crypt and lower villus compartment. 3. After separation of the brush border proteins by SDS gel electrophoresis from villus and crypt cells of sucrose refed rats, major incorporation of the radioactive precursor occured in the protein bands corresponding to sucrase and maltase activities of the lower villus and crypt cell brush borders. These findings demonstrate that sucrase stimulation by sucrose occurs mainly in the immature epithelial cells and that the substrate induces de novo synthesis of sucrase molecules.
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PMID:Effect of sucrose refeeding on disaccharidase and aminopeptidase activities of intestinal villus and crypt cells in adult rats. Evidence for a sucrose-dependent induction of sucrase in the crypt cells. 677 Sep 8

The effects of prolonged alcohol administration were studied on the brush border enzyme activities of the jejunum in rats receiving either a normal laboratory diet or a high carbohydrate-low protein for several weeks. Alcohol (15%) given in association with the normal diet provoked a stimulation of sucrase, maltase, and lactase activities after four weeks, but no significant modification in aminopeptidase activity. These results obtained for the disaccharidases were very similar to those observed with the high carbohydrate-low protein diet given without alcohol, although major differences were obvious in the timing of enzyme stimulation. In contrast, this dietary condition initiated a drop in aminopeptidase activity. When alcohol was given in association with the high carbohydrate-low protein diet, no modification in aminopeptidase activity was detected and the stimulation for the disaccharidase activities was similar to that observed with the high carbohydrate-low protein diet given alone. The present results suggest that the mechanisms involved in the stimulation of brush border disaccharidase activities were different for alcohol and for the high carbohydrate-low protein diet.
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PMID:Effects of prolonged alcohol administration and a high carbohydrate-low protein diet on the activities of the jejunal brush border enzymes in the rat. 681 99

The effect of dexamethasone (DX) on the prenatal maturation of rat intestinal brush border enzymes was studied in organ culture. Jejunal segments were explanted daily from day 17 of gestation until birth, as well as at different postnatal stages until day 6; they were cultured for 48 h with or without DX (8 X 10(-8) M). Enzymatic activities were analyzed on brush border membranes purified from cultured intestines and were compared with values from uncultured specimens. The results showed that DX elicited (a) a precocious induction of sucrase activity in the jejunum explanted from 19 days of gestation onward, reaching a peak value when taken at birth; (b) a stimulation of maltase activity in the segments explanted as soon as day 18, leading to maximal values when taken at day 20, the stage at which the stimulated activity reached a 6.5-fold increase over the baseline activity; and (c) an increase of lactase activity comparable to that occurring in utero. As opposed to this, DX has no specific action on alkaline phosphatase and aminopeptidase activities. The present data indicate that glucocorticoids directly and specifically influence the prenatal maturation of some brush border enzymes in the mammalian gut.
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PMID:Control of brush border enzymes by dexamethasone in the fetal rat intestine cultured in vitro. 682 Nov 11

The present study was performed to investigate the enzymatic changes in dystrophic chickens compared to those of dystrophic mice. The activities of 14 kinds of aminopeptidases, 5 kinds of endopeptidase, 4 kinds of glycosidases, phosphatase, esterase, and ribonuclease were measured in muscles of control and dystrophic chickens. When the enzyme activities were expressed as specific activity per unit weight of organs, only some of them were found to be significantly elevated in dystrophic chickens; e.g., alanine aminopeptidase (Ala-AP), Gly-AP and cathepsin D. On the contrary, the activities of alpha-D-glycosidase, alpha-D-galactosidase and alpha-D-mannosidase were significantly decreased. Muscular protein contents of dystrophic chickens also tended to be lower than those of controls. These observations offer a striking contrast with the one obtained in the study on dystrophic mice. However, when expressed as specific activity per mg protein, many enzyme activities were found to be significantly elevated suggesting an extensive abnormality of metabolism in dystrophic chickens. Among 14 kinds of aminopeptidase activities, highly significant elevations were seen especially in AP-A, AP-B, Gly-AP, Ala-AP, Ser-AP, Pro-AP, Leu-AP, Met-AP and Trp-AP. Interestingly enough, a statistical approach suggested a significant correlation between the aminopeptidase changes of dystrophic chickens with those of dystrophic mice. In addition to aminopeptidases, there were highly significant increases in the activities of cathepsin D, alpha-D-glucosidase, beta-D-galactosidase, alpha-D-mannosidase, esterase and RNase. These results indicate that the intramuscular metabolic abnormality of dystrophic chickens are generally different from but partly resembled with those of dystrophic mice.
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PMID:Intramuscular enzyme abnormalities of dystrophic chickens compared to those of dystrophic mice. 701 13

The API ZYM system (Analytab Products, Plainview, N.Y.), containing 19 chromogenic substrates, was utilized semiquantitatively to detect extracellular acid and alkaline phosphatases, aminopeptidases, proteases, esterase-lipase, phosphoamidase, and glycosidases in 128 oral and nonoral isolates of black-pigmented Bacteroides, Actinobacillus, Haemophilus aphrophilus, Capnocytophaga, Fusobacterium nucleatum, Wolinella recta, and Veillonella parvula. In the black-pigmented Bacteroides group of organisms, a strong trypsin reaction was present in Bacteroides gingivalis (oral species) but not in Bacteroides asaccharolyticus (nonoral species). Bacteroides melaninogenicus subsp. melaninogenicus, in contrast to Bacteroides melaninogenicus subsp. intermedius, exhibited strong N-acetyl-beta-glucosaminidase activity. H. aphrophilus produced beta-galactosidase and alpha-glucosidase, but the closely related Actinobacillus actinomycetemcomitans did not. Capnocytophaga was distinct with respect to strong aminopeptidase reactions. This study showed that a wide range of enzymes which have the potential of causing tissue injury and inflammation can be elaborated from major oral gram-negative species. Also, the API ZYM system appears to be a valuable adjunct to traditional biochemical testing in identifying oral gram-negative species.
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PMID:Enzymatic characterization of some oral and nonoral gram-negative bacteria with the API ZYM system. 702 98

Previous work in our laboratory and in others suggest that protein malnutrition plays an important role in the pathogenesis of hepatic dysfunction after jejunoileal bypass for morbid obesity. This experimental study was undertaken to attempt to correlate hepatic dysfunction (the criterion used was the bromsulphalein clearance) to morphological and enzymatic adaptation of the functioning intestine in the rat. It was observed that the period of impaired bromsulphalein clearance is concomitant with a slight ileal morphological adaptation and especially with a period of selective adaptation of maltase and sucrase activities, whereas there is no increase in aminopeptidase activity. These data support the hypothesis that after jejunoileal bypass a preferential absorption of carbohydrates along with a protein deficiency state could occur and as in kwashiorkor it results in an impaired nutritional status, a major contributing factor to bypass-induced liver injury.
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PMID:Imbalance in brush border enzyme activities as a possible cause of hepatic dysfunction after jejunoileal bypass in the rat. 704 83

Explants of pig small intestine were maintained at 37 degrees C in organ culture for periods up to 24 h in a system using Trowell T-8 medium supplemented with 10% foetal-calf serum. The mucosal morphology was well preserved during culture, as judged by light and electron microscopy. The explant contents of protein and two brush-border enzymes, microvillus aminopeptidase (EC 3.4.11.2) and dipeptidyl peptidase IV (EC 3.4.14.5), were not significantly modified during culture compared with controls, but a moderate, continuous release of both protein and enzyme activities into the medium was observed. Continuous labelling with [35S]methionine resulted in an even incorporation of radioactivity in the protein components, and the rate of labelling only moderately decreased over the 24 h period. The polypeptide compositions of sucrase (EC 3.2.1.48)--isomaltase (EC 3.2.1.10), maltase--glucoamylase (EC 3.2.1.20) lactase (EC 3.2.1.23)--phlorizin hydrolase (EC 3.2.1.62), microvillus aminopeptidase and aspartate aminopeptidase (EC 3.4.11.7) synthesized during culture were studied, and some were found to be similar to those of the pro-forms of the enzymes isolated from animals that had had their pancreatic duct disconnected 3 days before being killed. These results confirmed earlier findings of the existence of pro-forms of some of the microvillar enzymes and thus indicate a low activity of pancreatic proteinases in the culture system.
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PMID:Biosynthesis of intestinal microvillar proteins. Characterization of intestinal explants in organ culture and evidence for the existence of pro-forms of the microvillar enzymes. 709 36


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