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

---

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

The development of immune-mediated diabetes in BB rats may involve a defect of the gastrointestinal tract (GI), as suggested by increased gut permeability. This study aimed at measuring invertase, maltase, lactase, and peroxidase activities in the duodenum of diabetesprone BioBreeding (BBdp) rats and control BioBreeding rats (BBc) given free access to NIH-07 diet up to the time of killing at 60 66 d of age. After washing the entire small intestine, the duodenal mucosa was scraped off in the first 5-cm segment from the pylorus and frozen in distilled water. Invertase, maltase, and lactase activities were measured by monitoring the conversion of [U-(14)C]sucrose, [U-(14)C]maltose, and [D-[1-(14)C]glucose] lactose to radioactive hexoses, which were phosphorylated in the presence of adenosine triphosphatase and yeast hexokinase and then separated from their precursor by ion-exchange chromatography. Peroxidase activity was measured by a spectrophotometric procedure. In the BBdp rats, the activity of invertase, maltase, and lactase averaged, respectively, 70.2 +/- 4.4, 81.2 +/- 4.3, and 75.7 +/- 4.1% (n = 16 and p < 0.001 in all cases) of the control values found in BBc rats of the same sex. Inversely, after exclusion of two female BBc rats with abnormally high plasma D-glucose concentration, the activity of peroxidase in the BBdp rats averaged 157.4 +/- 20.0% (n = 16; p < 0.02) of the mean control value recorded in BBc rats of the same sex (100.0 +/- 9.3%; n = 14). These findings are compatible with the view that a proinflammatory state of the GI associated with compromise function may precede the occurrence of pancreatic insulitis in BBdp rats and, possibly, human subjects with type 1 diabetes.
...
PMID:Invertase, maltase, lactase, and peroxidase activities in duodenum of BB rats. 1262 29

When fed in semi-artificial diet in short- and long-term bioassays, the lectins from snowdrop (Galanthus nivalis; GNA) and jackbean (Canavalia ensiformis; Con A) affected the activities of soluble and brush border membrane (BBM) enzymes in the midgut of Lacanobia oleracea larvae. In the short term both lectins increased gut protein levels and BBM aminopeptidase activity. The lectins also increased trypsin activity, both in the gut (Con A) and in the faeces (GNA). GNA also increased the activity of alpha-glucosidase, but neither lectin had a significant effect on alkaline phosphatase activity. Trypsin mRNA levels were similar in lectin-fed and control larvae in the short term, showing that there is no direct effect on expression of the encoding genes. Larvae chronically exposed to GNA and Con A showed reductions in weight of 50-60%, and exhibited a significant reduction in alpha-glucosidase activity, but little change in other enzyme activities. Con A bound to many BBM and peritrophic matrix (PM) proteins in vitro, whereas GNA showed more specific binding, with strongest binding to a 94kDa uncharacterised BBM protein. Both lectins accumulated in gut tissues of insects after chronic exposure in vivo, but Con A was present at higher levels than GNA.
...
PMID:A comparison of the short and long term effects of insecticidal lectins on the activities of soluble and brush border enzymes of tomato moth larvae (Lacanobia oleracea). 1277 Mar 21

Larval and adult Psacothea hilaris feed on mulberry wood and leaves, respectively. High levels of endogenous activity against the major dietary carbohydrates, cellulose, hemicellulose, starch and soluble sugars were secreted in the gut of larvae and adults. Activity against pectin was also high and multiple polygalacturonase (EC 3.2.1.15) components were secreted in the gut of larvae. One glycanase component, beta-EG1, which was primarily an endo-beta-1,4-glucanase (EC 3.2.1.4) and another, beta-EG2, which was mostly an endo-beta-1,4-xylanase (EC 3.2.1.8), were also secreted, while at least four additional components hydrolysed laminarin, lichenin and crystalline cellulose. The beta-glycosidase component beta-GD1 was associated with most of the beta-mannosidase (EC 3.2.1.25) and beta-xylosidase (EC 3.2.1.37) activity secreted in the gut of larvae, while another, beta-GD2, was a beta-glucosidase (EC 3.2.1.21), the activity of which was directed against cellobiose and other beta-linked disaccharides, and a beta-fucosidase (EC 3.2.1.38). A beta-galactosidase (EC 3.2.1.23), which did not hydrolyse lactose, was also secreted, as were distinct beta-N-acetylhexosaminidase (EC 3.2.1.52), trehalase (EC 3.2.1.28), alpha-L-arabinosidase (EC 3.2.1.55), alpha-galactosidase (EC 3.2.1.22) and a minimum of four alpha-glucosidase (EC 3.2.1.20) components, one of which was also likely to be associated with a peak of alpha-mannosidase (EC 3.2.1.24) activity. The alpha-glucosidase components varied in their specificity for alpha-linked disaccharides, but none was active against sucrose, which was hydrolysed by a beta-fructofuranosidase (EC 3.2.1.26) component. Overall average levels of activity in larvae were twice those of adults, but the secretion of individual carbohydrases in both was not regulated in response to the relative abundance of particular carbohydrate components in their respective diets.
...
PMID:Diet and carbohydrate digestion in the yellow-spotted longicorn beetle Psacothea hilaris. 1277 Apr 76

It has been known that Hyssopus officinalis (hyssop) is a herb that grows in the wild and is a source of natural antioxidants. We previously reported that a-glucosidase inhibitors, (2S, 3S)1-O-beta-D-6'-O-cinnamoylglucopyranosyl-3-(3", 5"-dimethoxy-4"-hydroxyphenyl)-1,2,3-propanetriol and (2S, 3S)1-O-beta-D-glucopranosyl-3-(3", 5"-dimethoxy-4"-hydroxyphenyl)-1,2,3-propanetriol, from the dry leaves of hyssop, were isolated. This study examined the alpha-glucosidase inhibitory effects of hyssop extracts on intestinal carbohydrate absorption in rat everted gut sac and carbohydrate-loaded hyperglycemia in mice. In the everted gut sac experiment, 10 mM sucrose- and 5 mM maltose-treated increases in glucose concentration in the serosal compartment were inhibited in the presence of 0.5 and 1.0 mg/ mL hyssop extracts, although a 10 mM glucose-induced increase in serosal glucose was not inhibited by the extracts. Additionally, hyperglycemia in sucrose- and maltose-loaded mice was significantly suppressed at an early stage, within 30 to 60 min by oral pre-administration of 300 and 100 mg/kg hyssop extracts, respectively. These findings suggest that hyssop extracts inhibited the digestion of complex carbohydrates, but not that of absorbable monosaccharide, and might be a useful supplemental food for hyperglycemia.
...
PMID:Inhibitory effects of hyssop (Hyssopus officinalis) extracts on intestinal alpha-glucosidase activity and postprandial hyperglycemia. 1470 10

Diabetes-prone BioBreeding (BBdp) rats often present an enteropathy that may precede the onset of autoimmune insulitis. The aim of the present study was to assess the influence of sex, the time course, the strain specificity, the distribution along the intestinal tract and the effect of diet for the changes in the activity of gut invertase, maltase and lactase found in BBdp rats, as compared with both Wistar-Furth (WF) and diabetes-resistant BioBreeding (BBc) rats. These hydrolases were measured, therefore, at day 10, 30, 45, 70, 95 and 120 in three intestinal segments of WF, BBc and BBdp rats fed, after weaning, either a protective hydrolysed casein diet, which decreases the incidence of diabetes in the BBdp rats, or one of two diabetogenic diets (National Toxicology Program; NTP or wheat-gluten-based; WG) [corrected]. Except for a somewhat lower lactase activity in the BBdp rats, no obvious difference in hydrolyase activity between the three strains of rats was observed at day 10. Between days 30 and 120, however, the activity of the hydrolases, especially that of invertase and lactase, was lower in the BBdp rats than in either the WF or BBc rats, at least when considering the animals fed either the NTP or WG diet. These findings support the view that BBdp rats exposed to a diabetogenic diet develop an enteropathy well before the onset of autoimmune insulitis, in a manner somehow comparable with the situation found in some type 1 diabetic patients, in whom coeliac disease may be diagnosed before diabetes onset.
...
PMID:Disaccharidase activity in the intestinal tract of Wistar-Furth, diabetes-resistant and diabetes-prone BioBreeding rats. 1475 5

Flowerpiercers are the most specialized nectar-feeding passerines in the Neotropics. They are nectar robbers that feed on the sucrose-rich diet of hummingbirds. To test the hypothesis that flowerpiercers have converged with hummingbirds in digestive traits, we compared the activity of intestinal enzymes and the gut nominal area of cinnamon-bellied flowerpiercers (Diglossa baritula) with those of eleven hummingbird species. We measured sucrase, maltase, and aminopeptidase-N activities. To provide a comparative context, we also compared flowerpiercers and hummingbirds with 29 species of passerines. We analyzed enzyme activity using both standard allometric analyses and phylogenetically independent contrasts. Both approaches revealed the same patterns. With the exception of sucrase activity, hummingbirds' digestive traits were indistinguishable from those of passerines. Sucrase activity was ten times higher in hummingbirds than in passerines. Hummingbirds and passerines also differed in the relationship between intestinal maltase and sucrase activities. Maltase activity was two times higher per unit of sucrase activity in passerines than in hummingbirds. The sucrase activity of D. baritula was much lower than that of hummingbirds, and not unlike that expected for a passerine of its body mass. With the exception of aminopeptidase-N activity, the digestive traits of D. baritula were not different from those of other passerines.
...
PMID:Sugar and protein digestion in flowerpiercers and hummingbirds: a comparative test of adaptive convergence. 1475 1

The sea urchin embryo is a model for studying cellular interactions that occur in higher organisms because of its availability, transparency, and accessibility to molecular probes. In previous studies, we found that the mannose/glucose-binding lectin Lens culinaris agglutinin entered living sea urchin embryos, bound to specific cell types and caused exogastrulation, when the developing gut (archenteron) falls out of the embryo proper. We have proposed that the lectin bound to sugar-containing ligands, thus preventing attachment of the archenteron to the blastocoel roof, resulting in exogastrulation. Here, we have continued our study of cellular interactions in this model using Lytechinus pictus sea urchin embryos, and have found that inhibitors of glycoprotein/proteoglycan synthesis, tunicamycin and sodium selenate, and the specific glycosidases, beta-amylase, alpha-glucosidase, and alpha-mannosidase, all inhibit archenteron organization, elongation, and attachment to the blastocoel roof in viable swimming embryos. We also show that single cells obtained by disaggregation of 32-h-old sea urchin embryos bind to L. culinaris agglutinin- and concanavalin A-derivatized beads; the binding is blocked by alpha-methyl mannose, but not l-fucose. These cells also bind to beads derivatized with mannan. These results provide evidence for a role of carbohydrate-containing molecules in cellular interactions in sea urchin gastrulation. In a second set of experiments, we found that the supernatant obtained by disaggregation of 24-32-h-old L. pictus embryos in calcium- and magnesium-free sea water contains molecules that cause exogastrulation, archenteron disorganization, inhibition of archenteron elongation and inhibition of archenteron attachment to the blastocoel roof in viable swimming embryos. We propose that the supernatant contains ligands and/or receptors that mediate archenteron development and attachment to the blastocoel roof and are released when embryos are disaggregated into single cells. These studies may lead to a better understanding of the molecular basis of mechanisms that control cellular interactions during development.
...
PMID:Carbohydrate involvement in cellular interactions in sea urchin gastrulation. 1514 30

Numerous individuals complain of malaise attributed to hypoglycaemia. However, the diagnosis of hypoglycaemia is rarely documented and most often overstated. Reactive hypoglycaemia in the postprandial state is rather exceptional. The diagnosis relies upon the measurement of plasma glucose concentration (< 3 mmol/l or 55 mg/dl) at the time of the malaise. Reactive hypoglycaemia is generally associated with adrenergic symptoms and, less often, with cognitive disturbances. Importantly, a plasma glucose concentration below 3 mmol/l during an oral glucose tolerance test is not sufficient to decide that the patient suffers from reactive hypoglycaemia. Treatment is based on dietary advices including frequent small split meals and limitation of carbohydrates with high glycaemic index. Acarbose, a specific inhibitor of gut alpha-glucosidase enzymes, may be helpful in case of diet failure. As compared with true reactive hypoglycaemia, a postprandial hyperadrenergic reaction without real concomitant hypoglycaemia is much more prevalent. Careful anamnesis may suspect such a diagnosis, but other diagnoses such as panic attack or vasovagal reaction should be excluded. Treatment is purely symptomatic and essentially empiric.
...
PMID:[Reactive hypoglycaemia, a mysterious, insidious but non dangerous critical phenomenon]. 1518 36

Enzyme activities associated with the labial glands, midgut and rectum of adult Acromyrmex subterraneus were investigated in order to understand their role in digestion of plant and fungal material. High chitinolytic activity was detected in the labial glands, indicating a possible role in the degradation of fungus ingested by the ants. Chitinolytic activity seen in other compartments of the alimentary canal probably originated in the labial glands. The highest activity detected in the midgut was for alpha-glucosidase, which was considered to be of insect origin due to its association with midgut epithelium and it is probably involved in glucose assimilation from nutrient sources such as maltose and sucrose present in plant material. A large range of enzyme activities were detected in the rectal lumen contents, and as in the midgut the highest values were for alpha-glucosidase activity. The absence of activity associated with the epithelium, in the particulate fraction, indicates that the rectal epithelium does not have a secretory function. The detection of enzymes in the rectal lumen contents, which were not detected in the midgut lumen contents, indicates that the rectum acts as a reservoir, accumulating enzymes. The major digestive enzymes were partially characterized using hydrophobic interaction chromatography, gel filtration and SDS-PAGE. The pH of the adult intestinal tract and flow rate of dye through the tract was investigated. A gradual acidification of the intestinal tract was noted commencing with the crop (pH 6-8.2) and terminating with the rectum (pH 3-5). The flow of dye through the different compartments of the tract showed a rapid fill time for all the gut compartments and a short residence time in the crop. In all other compartments, the dye remained detectable for 10 days or longer.
...
PMID:Digestive enzymes of leaf-cutting ants, Acromyrmex subterraneus (Hymenoptera: Formicidae: Attini): distribution in the gut of adult workers and partial characterization. 1551 56

We have determined the occurrence of responses at different levels (morphological, physiological and biochemical) in the omnivorous rodent Akodon azarae upon cold acclimation (15 degrees C). A short-term enhancement in food consumption appeared to account for the maintenance of both mass and body composition. At the morphological level, the main response was an increase in the dimensions of small intestine, which constitutes the section of the gut where absorption and secretion take place. An increase in sucrase specific activity was only found in small intestine. Sucrose independent maltase activity was very low since 99.8% of total maltase activity was due to sucrase-isomaltase (SI) complex. Protease specific activities were not affected. The fact that resting metabolic rates determined at 15 and 23 degrees C were similar in cold acclimated animals suggests a change in lower critical temperature. In conclusion, our results show that A. azarae exhibits different strategies to support cold environment that could lead to an enhancement in digestion and absorption efficiency. Furthermore, this work suggests that low temperature is an independent cue of other environmental factors to trigger the strategies allowing the maintenance of body condition in A. azarae.
...
PMID:Phenotypic flexibility of digestive morphology and physiology of the South American omnivorous rodent Akodon azarae (Rodentia: Sigmodontinae). 1559 96


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---