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)

Maltase, sucrase, and lactase were measured at pH 4 and pH 6 in normal and intestinalized gastric mucosa. In the normal mucosa the low activities of maltase and lactase seemed to be entirely due to lysosomal enzymes with acid pH-optimum. In intestinal metaplasia, brush border maltase and sucrase, but not lactase, appeared. On the other hand, there was a significant increase in lysosomal lactase (beta-galactosidase) activity.
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PMID:Disaccharidase activities in intestinal metaplasia - contribution of lysosomal brush border enzymes. 117 60

Meconium ileus represents the earliest clinical manifestation of cystic fibrosis. The differences found in the composition and amount of protein, mucoprotein, mucopolysaccharides, and reducing sugars in meconium from newborns with cystic fibrosis might be of significance relative to the pathogenesis and early diagnosis of this disease. We studied the enzymatic activity of disaccharidases (lactase, sucrase, maltase, and palatinase) in meconium of infants with cystic fibrosis and controls. We found an increase in the specific activity of these enzymes in the meconium from infants with cystic fibrosis as compared to the specific activity in meconium from normal infants. The increase in the activities, expressed as micromols per gram of protein per minute was: lactase, 100 times higher; sucrase, 18 times; maltase, 4.8 times, and palatinase, 8.9 times.
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PMID:Studies in meconium: disaccharidase activities in meconium from cystic fibrosis patients and controls. 119 37

In 59 persons of advanced (60-74 years) and in 17 others of senile (75-89 years) age the activity of disaccharides in the small intestine was studied. In the past history of all the examinees no affections of the gastro-intestinal tract were recorded. As controls 26 healthy subjects aged 20-26 were examined. It was noted that the activity of maltase in the duodenal mucosa declined in advanced age and of maltase, lactase and saccharase - in senility. In jejunal mucosa the activity of maltase and lactase proved less active in persons of senile age. The reduced activity of intestinal disaccharides is attended by atrophy of the jejunal mucosa.
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PMID:[Activity of intestinal disaccharidases in human aging]. 121 Feb 24

In 63 infants and children with a histological normal mucosa of the duodenum, without an isolated defect of enzyme and with a normal increase of xylose and glucose in serum after a combined xylose-lactose loading test the activities of disaccharidases were log normal distributed. The asymmetric distributions were transformed into symmetric ones and the geometric mean (x) as well as the range (+/- 2 s) of maltase, saccharase, isomaltase, lactase and trehalase were calculated. Only the activity of lactase shows a significant dependency on age. In the first year of age the lower limit (x -- 2 s) of this enzyme is much higher than later.
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PMID:[Disaccharidases of the small intestine mucosa in infants and children. "Normal values", log normal distribution and age dependence]. 122 50

Intestinal DNA, RNA, and protein content were decreased to a greater extent than was body weight when rats were starved for 3 days. Specific lactase and maltase activity increased with progressively longer periods of starvation. Antral and serum gastrin concentration significantly decreased during the 3 days of starvation. Pentagastrin (250 mug/kg 3 times daily) was injected into a group of rats for the duration of a 3-day starvation period and caused a small but significant increase in the relative intestinal RNA and protein content and decreased lactase and maltase specific activities in comparison with the levels of 3-day starved controls. Pentagastrin thus partially reversed some of the starvation-induced changes toward fed levels. Thus, a deficiency in the trophic hormone gastrin may be partially responsible for the disproportionate changes in intestinal tissue during starvation.
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PMID:Relationship between the changes in gastrin levels and intestinal properties in the starved rat. 125 47

The releases of proteins, maltase, lactase, sucrase, trehalase, alkaline phosphatase, gamma-glutamyltransferase and leucylnaphthylamide-hydrolyzing activity from human intestinal brush bborder membrane vesicles by various enzymes (especially pancreatic proteases) have been studied. The brush border membrane enzymes are not solubilized by digestion with trypsin and chymotrypsin but are largely released after treatment with papain or elastase. Most of the enzymes are fully active after the proteolytic treatment. All proteins released by papain and elastase have been identified by electrophoresis to already known intestinal hydrolases. Electron microscopy of brush border membrane vesicles demonstrates "knob-like" structures (particles) attached to the external side of the membrane. During papain treatment, enzyme removal runs parallel with the disappearance of the particles. During elastase treatment it is not possible to correlate the release of the enzymic activities with the removal of the particles. The results indicate that most of the intestinal hydrolases are surface components attached to the external side of the membrane. They are in accord with the concept that the brush border membrane enzymes are organized within the membrane in a mosaic-like pattern.
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PMID:Enzymic solubilization of the human intestinal brush border membrane enzymes. 127 90

The activity of the small intestine's peptide hydrolases is higher in 1-day old rats than in adult rats, whereas levels of activity of alkaline phosphatase and diglycyl glycine peptidase do not differ significantly in these two groups of the rats. Our own data on carbohydrases corroborate other authors' evidence and reveals that activities of lactase, sucrase and maltase are either absent or very low in the first days of life and sharply increase by the third week of postnatal development. Adaptive changes of regulatory properties of lactase and alkaline phosphatase are revealed.
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PMID:[The detailed characteristics of the enzyme spectrum of the small intestine in rats in the early postnatal period]. 133 21

1. Lactase, sucrase, maltase, trehalase and alkaline phosphatase activities of rat proximal jejunum were measured in 3, 6, 9, 12, 18 and 24-month-old rats fed with diets differing in their fatty acid composition. 2. A drop of 47-53% of the specific enzyme activity was observed with disaccharidases against a decrease of 71% for alkaline phosphatase in the 24-month-old rats compared to the 3-month-old rats. 3. Changes in dietary fatty acid composition, either in the saturated or monounsaturated ratio, or in the polyunsaturated fatty acid composition, did not significantly interfere with this aging effect.
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PMID:Diet fatty acid composition, age and rat jejunal microvillus enzyme activities. 134 82

The brush border of normal small-intestine epithelial cells is rich in enzymes that are involved in the digestive process. Such molecules can be used as markers to analyze cell lineages and differentiation properties of colorectal cancers. Monoclonal antibodies detecting dipeptidyl peptidase-IV, aminopeptidase N, endopeptidase F, sucrase-isomaltase, alkaline phosphatase, maltase-glucoamylase and lactase have been used to analyze the phenotype of colorectal cancers, adjacent mucosa and histologically normal distant mucosa. The avidin-biotin peroxidase complex method was used. Expression of dipeptidyl peptidase-IV, aminopeptidase N, sucrase-isomaltase and alkaline phosphatase was common in non-neoplastic mucosa adjacent to, and distant from, the tumor; in contrast, endopeptidase F, maltase-glucoamylase and lactase were rarely expressed in normal distant mucosa and more frequently expressed in mucosa adjacent to the tumor. Dipeptidyl peptidase-IV, aminopeptidase N, endopeptidase F, sucrase-isomaltase and alkaline phosphatase were frequently expressed in colorectal cancers, whereas maltase-glucoamylase and lactase were rarely expressed. Two general patterns of antibody reactivity were observed: diffuse cytoplasmic and apical; apical reactivity was generally associated with more differentiated tumors. A logistic predictive regression model indicated that enzyme expression in colorectal cancers followed a coordinate pattern, but was unrelated to the location of the tumor, Dukes stage or differentiation grade. In conclusion, expression of brush-border-associated enzymes occurs frequently in colorectal cancers and is regulated in a co-ordinated manner. These markers can be used for the phenotypic sub-classification of colorectal cancers.
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PMID:Intestinal brush-border-associated enzymes: co-ordinated expression in colorectal cancer. 134 6

The chronic diarrhea observed in young malnourished infants that is sensitive to dietary glucose and other carbohydrates is associated with variable degrees of patchy mucosal villous atrophy. To explore intrinsic mucosal function in the pathogenesis of this alimentary intolerance, we have conducted an immunohistologic investigation of brush-border enzyme proteins of clinically obtained, mucosal biopsy samples. We used a group of monoclonal antibodies against human brush-border aminopeptidase, sucrase/isomaltase (SI), maltase, and lactase enzyme proteins. SI was strongly and uniformly expressed in crypts and villi of 11 of the 14 subjects; in 3 subjects, however, SI was expressed in a mosaic pattern. Maltase and lactase were occasionally absent, but more commonly were expressed in a mosaic distribution. The mosaic expression of brush-border enzyme proteins has been reported in congenital enzyme deficiencies associated with normal intestinal histology. We report the mosaic expression of brush-border enzyme proteins as a functional alteration associated with a pathological lesion of the mucosa in infants with chronic diarrhea. Our observation challenges the existing concept of ontogenic regulation of brush-border enzyme activity.
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PMID:Mosaic expression of brush-border enzymes in infants with chronic diarrhea and malnutrition. 135 33


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