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)

1. The role of endogenous CCK in the development of digestive enzyme activities in small intestine and pancreas was investigated in suckling rats. Synthetic protease inhibitor (camostat 100 micrograms/g bwt) was orally administered twice daily for 5 days from 11 days of age. 2. Pancreatic hypertrophy and hyperplasia, and alteration of pancreatic enzyme composition, especially decreases in amylase activity and increases in trypsin and chymotrypsin activities were produced by camostat treatment. These changes were completely suppressed by simultaneous administration of the potent CCK receptor antagonist L-364,718 (1 microgram/g bwt). 3. With camostat treatment, intestinal lactase activity decreased to 41%, while maltase and sucrase activities increased 3 and 2.5 times respectively. These changes in enzyme activities were not affected by the application of L-364,718. 4. The mucosal disaccharidase and pancreatic enzyme activities could not be modified by chronic subcutaneous injection of camostat. The precocious induction of maltase and sucrase activities by camostat treatment was also observed in the adrenalectomized pups. 5. These results indicate that pancreatic growth accompanied by alteration of digestive enzyme composition in the suckling rats is regulated by endogenous CCK, but the precocious induction of disaccharidase activities is not mediated by endogenous CCK released by camostat treatment.
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PMID:Precocious alteration of digestive enzyme activities in small intestine and pancreas by chronic oral administration of protease inhibitor in suckling rats. 168 62

In order to evaluate the renal metabolism of amylase and immunoreactive trypsin (IRT) in chronic pancreatic disease, we assayed amylase, IRT and creatinine in serum and urine and gamma-glutamyl transferase (GGT) in dialyzed urine as well as alpha-glucosidase (AGL) and ribonuclease (RNase) in 24 control subjects, 34 patients with pancreatic cancer, 52 with chronic pancreatitis and 32 with extra-pancreatic diseases. Urinary amylase and IRT outputs were found to be more elevated in chronic pancreatitis than in control subjects. The levels of serum amylase, its renal inputs and outputs were correlated with the corresponding IRT values. Multiple regression analyses (dependent on amylase or IRT urinary outputs, circulating levels of the two enzymes, creatinine clearance and the excretion of GGT, AGL and RNase predictor variables) showed significant correlations. The standardized partial regression coefficients found to be significant were: GGT, RNase and serum amylase for amylase, and GGT and RNase for IRT. No difference was found between amylase and IRT outputs in patients with chronic pancreatitis, taking the presence or the absence of alcohol abuse, exocrine insufficiency and pancreatic pseudocysts into consideration. Urinary GGT excretion correlated with serum amylase and IRT levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Renal handling of amylase and immunoreactive trypsin in pancreatic cancer and chronic pancreatitis. 169 Oct 65

This study investigates digestive and lysosomal enzyme secretion of azaserine-induced pancreatic acinar carcinomas in response to cholecystokinin in rats. After 15-20 months of treatment, 95% of the animals developed pancreatic acinar carcinomas encompassing more than 90% of the tissue. In anesthetized rats basal trypsin output was significantly elevated in the tumor group despite diminished fluid secretion. There was a linear correlation between tumor size and basal amylase and trypsin secretion. Intravenous infusion of cholecystokinin (25 IDU.kg-1.h-1) induced a significantly lower secretion of fluid per gram pancreas, as well as decreased amylase and trypsin output, in the tumor group compared with the control group. Plasma amylase and lipase levels were significantly elevated in the tumor group under both basal and stimulated conditions. The output of the lysosomal enzymes beta-D-glucuronidase and alpha-D-glucosidase was significantly increased in the tumor group under background secretin infusion. Additional cholecystokinin infusion caused a sharp increase in glucuronidase output in this group with only minimal increase in controls. Glucosidase output increased similarly in both groups. Amylase, lipase, and trypsin tumor tissue concentrations were markedly reduced by 85%, 90%, and 87%, respectively. It was concluded that the decreased secretory response of digestive enzymes may result from decreased synthesis, lowered storage capabilities, and/or a decreased/increased responsiveness to cholecystokinin. Increased glucuronidase secretion may reflect an augmented cell turnover of malignant tissue.
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PMID:Secretagogue response of azaserine-induced rat pancreatic acinar tumors in vivo. 171 May 88

Developing embryos and hatchling poults were sampled (n = 4) at Days 22, 24, 26, and 28 of incubation and at 1, 2, 4, 6, and 8 days after hatching, and selected characteristics of the gastrointestinal tract (GIT) were measured. Body weight increased linearly up to day of hatching and also from 2 to 8 days posthatching. Residual yolk weight decreased rapidly starting on Day 26 of incubation and was nearly depleted by 4 days posthatching. Changes in weight of segments of the GIT nearly paralleled the increase in body weight until day of hatching. Thereafter, weights of the proventriculus, small intestine, and pancreas increased more rapidly than body weight until 6 days after hatching. At this time, change in weight of small intestine and pancreas seemed to parallel that of body weight, whereas proventriculus weight continued to increase more rapidly. Gizzard weight, as a percentage of body weight, increased until Day 4 posthatching and then remained relatively constant through 8 days. Specific activities (SA) of pancreatic amylase, lipase, and trypsin were low until after hatching. Subsequently, amylase SA increased nearly threefold by Day 6. Lipase SA remained nearly constant between Days 1 and 8, and trypsin SA increased only slightly. Total activities of pancreatic enzymes, however, increased substantially after hatching, mainly because of increased pancreas weight. Jejunal maltase SA was high at hatching but decreased markedly by Day 4. This decrease in SA resulted in a notable reduction in total maltase activity of the jejunum despite an increase in jejunum weight.
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PMID:Developmental patterns of selected characteristics of the gastrointestinal tract of young turkeys. 171 68

The activities of trypsin, aminopeptidase, and alpha-glucosidase were studied in the whole midgut, anterior and posterior midgut, and posterior midgut lumen and epithelium of the mosquito Anopheles stephensi Liston. Trypsin activity was restricted entirely to the posterior midgut lumen. No trypsin activity was found before the blood meal, but activity increased continuously up to 30 h after feeding, and subsequently returned to baseline levels by 60 h. Aminopeptidase was active in anterior and posterior midgut regions before and after feeding. In whole midguts, activity rose from a baseline of approximately 3 enzyme units (EU) per midgut to a maximum of 12 EU at 30 h after the blood meal, subsequently falling to baseline levels by 60 h. A similar cycle of activity was observed in the posterior midgut and posterior midgut lumen, whereas aminopeptidase in the posterior midgut epithelium decreased in activity during digestion. Aminopeptidase in the anterior midgut was maintained at a constant low level, showing no significant variation with time after feeding. alpha-glucosidase was active in anterior and posterior midguts before and at all times after feeding. In whole midgut homogenates, alpha-glucosidase activity increased slowly up to 18 h after the blood meal, then rose rapidly to a maximum at 30 h after the blood meal, whereas the subsequent decline in activity was less predictable. All posterior midgut activity was restricted to the posterior midgut lumen. Depending upon the time after feeding, greater than 25% of the total midgut activity of alpha-glucosidase was located in the anterior midgut. The enzyme distributions are consistent with described structural models for digestion in mosquitoes. After blood meal ingestion, proteases are active only in the posterior midgut. Trypsin is the major primary hydrolytic protease and is secreted into the posterior midgut lumen without activation in the posterior midgut epithelium. Aminopeptidase activity is also luminal in the posterior midgut, but cellular aminopeptidases are required for peptide processing in both anterior and posterior midguts. alpha-glucosidase activity is elevated in the posterior midgut after feeding in response to the blood meal, whereas activity in the anterior midgut is consistent with a nectar-processing role for this midgut region.
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PMID:Blood digestion in the mosquito, Anopheles stephensi Liston (Diptera: Culicidae): activity and distribution of trypsin, aminopeptidase, and alpha-glucosidase in the midgut. 177 May 23

Extracts from Xenopus eggs capable of nuclear envelope assembly in vitro were fractionated by differential and density gradient centrifugation. Nuclear envelope assembly was found to require soluble components in the cytosol and two distinct particulate fractions, which we have called nuclear envelope precursor fractions A and B (NEP-A and NEP-B). Both NEP-A and NEP-B are sensitive to treatments with trypsin, sodium carbonate, and detergents, but can be distinguished from each other by their sensitivities to high salt and N-ethylmaleimide and by their levels of alpha-glucosidase activity. Vesicles in NEP-B bind to chromatin, whereas those in NEP-A do not. NEP-B may therefore be involved in the targeting of membranes to the surface of the chromatin, whereas NEP-A may provide a pool of vesicles that contributes many of the nuclear envelope membranes. NEP-B may also play a role in the assembly of nuclear pore complexes because the density of nuclear pores in the resulting envelope is dependent on the ratio of NEP-B to NEP-A in the reconstituted extract.
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PMID:A distinct vesicle population targets membranes and pore complexes to the nuclear envelope in Xenopus eggs. 199 30

The in vitro effects of human duodenal secretions and various combinations of its components on activity and release of enzymes from the human brush border were examined. Sucrase retained activity for 90 min in duodenal secretions, and maltase was almost as stable; lactase lost activity rapidly and alkaline phosphatase was of intermediate stability. Inactivation of lactase could only be partly (50%) attributed to luminal proteases, bile salts and phospholipids played no role. Rate of release of an enzyme from the brush border bore no relationship to its rate of inactivation. When individual proteases were studied, elastase was the most potent for releasing disaccharidases from the brush border; trypsin was ineffective alone but augmented the effect of elastase. Sucrase and maltase were activated by proteolytic release, but activation was abolished by simultaneous exposure of brush borders to bile salts. Lactase was released and rapidly inactivated by proteinases, while alkaline phosphatase appeared to be inactivated without significant release. These results show that there are significant interactions between luminal factors which have been inapparent when studying them in isolation. Loss of functionally useful enzyme does not follow release of sucrase or maltase from the brush border into the lumen but does follow release of lactase. Study of the susceptibility of lactase to inactivation by luminal factors in the various forms of lactose intolerance is warranted.
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PMID:Influence of duodenal secretions and its components on release and activities of human brush-border enzymes. 210 71

Experiments were conducted to establish a stunting syndrome (SS) model to facilitate research on nutritional aspects of enteric disorders of poults. One-day-old turkeys were dosed per os with tryptose phosphate broth (TPB) (controls) or inoculum (inoculated). The inoculum was prepared by homogenizing intestines from 11-day-old commercial poults diagnosed to have SS in TPB (1:0.5 [wt:wt]). Subsequently, intestines from 8-day-old inoculated poults from the previous experiment were used. Inoculation reduced growth (P less than 0.001) and feed consumption (P less than 0.001) at 8 and 14 days of age. In Expts. 1, 2, and 3, gain of inoculated poults was 60.9%, 58.8%, and 52.6% that of controls up to 8 days of age and 77.9%, 76.6%, and 80.9% that of controls from 8 to 15 days of age, respectively. Feed conversion was impaired (P less than 0.001) up to 8 days of age. The activity of maltase and sucrase in the jejunum and of pancreatic enzymes was determined every 2 days up to 13 days of age. Inoculation decreased (P less than 0.001) maltase and sucrase starting at 3 days of age (i.e., maltase activity was 17.45 and 1.70 mumols maltose hydrolyzed/hr.mg protein in control and inoculated poults, respectively). Inoculation had no effect on pancreatic lipase, amylase, or trypsin.
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PMID:Stunting syndrome in turkeys. Development of an experimental model. 219 47

This report deals with the effect of feeding inhibitors of pancreatic and brush border enzymes on pancreatic growth and enzyme composition and secretion. Raw soybean flour containing trypsin inhibitors caused pronounced growth of the pancreas which was accompanied by increased enzyme content and increased CCK and gastrin concentration in the plasma. Feeding of an amylase inhibitor to a starch-rich diet induced a marked fall in amylase content and secretion without changing growth parameters of the pancreas, indicating that not starch but glucose is the trigger for the maintenance of amylase content and secretion of the pancreas. The addition of an alpha-glucosidase inhibitor (acarbose) to a sucrose- or maltose-rich semisynthetic diet did not cause significant alteration in pancreatic growth or enzyme composition or secretion. In man pancreatic function was also unaltered by 8 weeks' intake of 3 X 200 mg acarbose.
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PMID:Adaptation of the pancreas during treatment with enzyme inhibitors in rats and man. 240 82

Neutral alpha-D-glucosidase (alpha-D-glucoside glucohydrolase, EC 3.2.1.20) from horse kidney brush-border membranes was solubilized using Emulphogene BC 720 and purified by an affinity chromatography technique. The enzyme preparation (390-fold purified), which was free of other known microvillus hydrolases, exhibited one precipitate line in crossed immunoelectrophoresis and migrated as a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis. Several criteria (charge-shift crossed immunoelectrophoresis and hydrophobic chromatography) revealed the purified detergent form of the enzyme to be an amphipathic molecule. The papain treatment of either brush-border membrane vesicles or the purified detergent form of neutral alpha-D-glucosidase released an enzymatic form devoid of these amphipathic properties. Conversely, after trypsin treatment of the "d' form of the enzyme, two enzymatic forms were obtained: the first and major form retained these amphipathic properties; the second form exhibiting the same properties as the papain-released form. Furthermore, only a very small amount of neutral alpha-D-glucosidase can be released after trypsin solubilization of brush-border membrane vesicles, and the released enzyme did not exhibit amphipathic properties. These results were interpreted as meaning that the trypsin attack site on the detergent form of the enzyme had either poor affinity for, or obstructed access to, the proteinase when the enzyme was integrated in native membrane or in Triton X-100 micelles, whereas the proteolytic site of the papain was always accessible.
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PMID:Horse kidney neutral alpha-D-glucosidase: purification of the detergent-solubilized enzyme; comparison with the proteinase-solubilized forms. 241 88


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