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)

The effects on glomerular and proximal tubular function of an ionic contrast agent (sodium meglumine diatrizoate) and a nonionic agent (iopamidol) were compared in 34 patients with normal renal function. The patients received large doses (2.5 ml/kg body weight) of contrast material for IV digital subtraction angiography. Urine samples, collected before, immediately after, and on the first and third days after digital subtraction angiography, were analyzed for albumin, alanil-aminopeptidase, alpha-glucosidase, and beta-2-microglobulin. The changes noted were mild and of short duration with both contrast agents, despite the high dose given. These results suggest that, at least as far as renal toxicity is measured by these tests is concerned, ionic monomers can be safely used instead of more expensive nonionic media in procedures, such as digital subtraction angiography, that require high doses of contrast material.
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PMID:Contrast agent nephrotoxicity: comparison of ionic and nonionic contrast agents. 289 Dec 85

To investigate further the pathophysiology of rotavirus-induced diarrhea, changes in specific activities of eight relevant intestinal enzymes [alkaline phosphatase, thymidine kinase, lactase, maltase, sucrase, Na+,K+-adenosine triphosphatase (ATPase), adenylate and guanylate cyclases] were measured following infection of suckling mice with murine rotavirus (epizootic diarrhea of infant mouse strain) and compared with age-matched control mice. The concentration of lactose within the lumen of the gastrointestinal tract during infection was also measured. During the course of infection, activities of alkaline phosphatase and lactase decreased, whilst the activity of thymidine kinase increased. Precocious maturation profiles of sucrase and maltase enzymes were observed. No significant changes were detected in the activities of Na+,K+-ATPase or the adenylate and guanylate cyclases. These results are discussed in relation to existing and novel hypotheses on the pathogenesis of rotavirus-induced diarrhea.
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PMID:Intestinal enzyme profiles in normal and rotavirus-infected mice. 289 74

1. In the newborn pig it appears that only prenatally produced enterocytes are capable of absorbing large amounts of protein. 2. The ability of the small intestine to transport sodium, lysine, lysine containing dipeptides and glucose declines markedly during the first week of post natal life. 3. Dexamethosone causes a doubling of the sodium dependent portion of alanine uptake. 4. EGF given between days three and six of postnatal life increases sucrase and maltase activity in the distal region of the small intestine. 5. Weaning induced problems are probably not due to direct inhibition of transport properties.
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PMID:Postnatal development of transport function in the pig intestine. 290 64

A model of nonischemic hypoxia of the jejunum was designed in dogs, by shunting of blood from the inferior vena cava directly into the regional mesenteric arterial supply, thereby lowering the PaO2 of the blood that reached the jejunal wall from 98.6 +/- 3 to 62 +/- 5 mm Hg. Absorption rates of sodium, glucose, fructose, glycine, and the dibasic aminoacid lysine were studied by in situ luminal perfusion of a 30-cm proximal jejunal segment with a bicarbonate buffer solution containing phenol red as a nonabsorbable marker for determination of water fluxes. During periods of control, hypoxia, and after discontinuation of the venoarterial admixture (recovery), effluent perfusate was collected and mucosal biopsies were obtained for assay of lactase, maltase and sucrase activity, mucosal ATPase activity and ATP content, and for light- and electron microscopic examination. Mesenteric supply with hypoxic blood was associated with a significant inhibition of Na+,K+-ATPase activity (p less than 0.001) and a rise in mucosal ATP content (p less than 0.05). There was a significant reduction in the absorption rates of sodium (p less than 0.001), glucose, and glycine (p less than 0.01), but no change in the transport of fructose and of lysine. Brush border enzymes were unaltered. The histological appearance of the mucosa remained normal throughout the experiment, but on electron microscopy a distinct swelling of the enterocyte mitochondria was noted during the hypoxia period.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of nonischemic hypoxia on jejunal mucosal structure and function: study of an experimental model in dogs. 294 46

Brush-border membrane fractions were isolated from rat duodenum. Purity and integrity of the fraction was confirmed by electron microscopy, enzymic analysis and demonstration of Na+-dependent glucose uptake. The membranes were enriched 15-fold in alkaline phosphatase and alpha-glucosidase and 6-fold in HCO3--ATPase activities. Assays of latent activity indicated that these enzymes were predominantly localised to the external aspect of the microvillus membrane. The enzymes were solubilised and subjected to analysis by gel filtration, ion exchange and phenylboronate chromatography. No separation of alkaline phosphatase and HCO3--ATPase was obtained and it is suggested that they reflect the same enzyme activity. The apparent activation by HCO3- was investigated, and was found to be due to shifts in the pH dependency of the activity due to changes in ionic strength.
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PMID:Studies on the localization and properties of rat duodenal HCO3--ATPase with special relation to alkaline phosphatase. 295 Sep 30

When studying mucosal barrier function of developing animals, we noted that intestinal microvillus membranes (MVM) of newborn animals differ in their fluidity and binding characteristics to lectins compared with adult MVM. To further investigate these differences and determine whether maturation of the microvillus surface could be accelerated in utero, pregnant rats were given intraperitoneal cortisone beginning on the 17th day of gestation. Control and cortisone-treated animals were allowed to deliver normally, and the small intestines from newborns were used to isolate MVM. Microvillus membrane surface characteristics were evaluated by employing an 125I-labeled fucose-specific lectin, Ulex europeus (UEA). Changes in MVM proteins were monitored by disaccharidase activities and sodium dodecyl sulfate-polyacrylamide electrophoresis. MVM fluidity was accessed using a 5-doxyl stearic acid label and electron-spin-resonance spectroscopy. Results from these studies indicate that the birth weights of newborn rats exposed to cortisone in utero were significantly reduced; sucrase activity was prematurely induced and specific activities of lactase and maltase were enhanced in the intestines of the cortisone-treated newborns as contrasted with control animals. Furthermore, binding of 125I-UEA to MVM was greatly increased in treated animals. MVM fluidity decreased (P less than 0.001) compared with control animals and resembled the structural characteristics of more mature MVM. These results suggest that cortisone exposure in utero accelerate maturation of the microvillus surface of enterocytes.
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PMID:Development of gastrointestinal mucosal barrier. VII. In utero maturation of microvillus surface by cortisone. 299 Feb 36

Purified brush border membranes were obtained from homogenized jejunal epithelial cells of cattle by divalent cation aggregation of nonbrush border membranes and differential centrifugation. Membrane marker enzyme assays determined effectiveness of the fractionation procedure. Compared with cellular homogenate, maltase and sodium+-potassium+-adenosine triphosphatase specific activities in the membrane fraction isolated from the interface of discontinuous (35 and 45% wt/wt) sucrose gradients increased 14.5- and 1.9-fold whereas enzyme recoveries averaged 20.2 and 2.4%. These data indicate significant enrichment in brush border membranes with minimal basolateral membrane contamination. Vesicles formed from this membrane fraction had a predominately (93%) luminal side out orientation. After incubating vesicles with radiolabeled substrates, vesicles and accumulated substrates were separated from the incubation buffer by filtration and substrate uptake quantified by liquid scintillation counting. Observed uptake was the result of substrate accumulation within an osmotically active intravesicular space and was not due to nonspecific binding of the substrate to vesicular membranes. Vesicles exhibited sodium-dependent and independent substrate uptake pathways and were able to discriminate between substrate stereoisomers for uptake. Major differences were not detected between results obtained with vesicles prepared from fresh or frozen intestines. These vesicles can be utilized to investigate nutrient uptake by the bovine small intestine.
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PMID:Preparation of brush border membrane vesicles from fresh and frozen bovine intestine for nutrient uptake studies. 300 74

Small intestinal biopsies from nine patients with sucrase-isomaltase deficiency (sucrose-intolerance) were analyzed. All patients lacked sucrase activity and three patients had a residual isomaltase activity and a corresponding isomaltase precipitate following immunoelectrophoresis. By polyacrylamide gel electrophoresis in sodium dodecyl sulfate followed by immunoblotting the residual isomaltase appeared as a single polypeptide with molecular weight of approximately 145,000. Maltase-glucoamylase in the biopsies was specifically quantitated by crossed immunoelectrophoresis. One of the patients had an almost total deficiency of maltase-glucoamylase in the biopsy, three patients had a normal amount of maltase-glucoamylase, and five patients constituted an intermediary group. These results indicate that some of the sucrase-isomaltase deficient patients also have a more or less pronounced deficiency of maltase-glucoamylase. The patients constitute an even more heterogeneous group than earlier suggested and should be classified by the amount not only of sucrase and isomaltase but also of maltase-glucoamylase.
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PMID:Maltase-glucoamylase and residual isomaltase in sucrose intolerant patients. 308 47

Although TPN is used frequently in young infants, little information is available regarding its effect on postnatal development of the gut. The effect of total parenteral nutrition (TPN) and intragastric (IG) alimentation on ontogeny of the small intestine was examined in infant rabbits starting at 10-12 days. Animals were killed at 17-19 days. Body weight, organ weight and weight of segments of proximal, mid and distal small intestine were measured. Intestinal mucosa was scraped, weighed and homogenized for estimation of protein, DNA and disaccharidases. Na+ transport was examined in short-circuited jejunum. Weight gain was similar in controls, sham-treated and TPN animals, but was significantly reduced in IG animals. TPN induced precocious development of sucrase and maltase activity and glucose-stimulated Na+ transport, despite causing a significant decrease in mucosal weight and DNA and pancreatic amylase. IG alimentation also induced precocious development of sucrase, maltase and glucose-stimulated Na+ transport. Thus TPN, despite producing mucosal atrophy and decreased pancreatic exocrine development, stimulates accelerated postnatal maturation of the small intestine.
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PMID:Effects of parenteral and enteral nutrition on postnatal development of the small intestine and pancreas in the rabbit. 310 3

Detergent-solubilized intestinal maltase-glucoamylase was isolated 1 week postpancreatectomy (dMpanc) and purified in the presence of detergent and protease inhibitors. Upon sodium dodecyl sulfate - polyacrylamide gel electrophoresis under nondissociating conditions, the major band had a molecular weight of 280,000, slightly smaller than similar bands from detergent (dM) and papain (pM) solubilized maltase from nonpancreatectomized rats. Upon octyl-Sepharose CL-4B chromatography, 57% of the enzyme was eluted by aqueous buffer, unlike pM which was almost completely eluted or dM, 95% of which bound to the column. All fractions of dMpanic from octyl-Sepharose 4B were reduced, by boiling +/- beta-mercaptoethanol, to monomeric subunits, indicating that processing by pancreatic enzymes at the level of the brush border is not a requirement for the appearance of subunits in the rat. As well, under these dissociating conditions, the 145,000 subunit previously identified with the apolar terminus was present in all fractions of dMpanc, including the aqueous fraction, whereas pM contained only the 130,000 subunit. The presence of dMpanc in the aqueous fraction cannot be explained, therefore, by proteolytic cleavage of an apolar anchor segment from the 145,000 subunit. Pancreatic enzymes may affect the enzyme in a minor fashion, however, since aqueous solubility was enhanced and the apparent molecular weight was reduced by pancreatectomy, suggesting a more compact conformation with shielding of apolar segments.
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PMID:Quaternary structure of intestinal maltase-glucoamylase in pancreatectomized rats. 311 99


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