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)

We examined GLUT-4 glucose transporter protein and mRNA in muscle tissue from a new rodent model of non-insulin-dependent diabetes mellitus (NIDDM), the male obese Zucker diabetic fatty (ZDF) rat [ZDF/Drt-fa(F10)]. We also determined whether prevention of hyperglycemia might affect GLUT-4 expression by feeding the intestinal alpha-glucosidase inhibitor acarbose (40 mg/100 g diet) in the diet of male ZDF rats for 19 wk, starting at least 1 wk before the onset of diabetes. Fasting glucose was four- to sixfold greater in diabetic ZDF rats (24.1 +/- 6.7 mM) compared with lean or obese nondiabetic rats. Fasting insulin in diabetic ZDF rats (0.5 +/- 0.1 ng/ml) was similar to lean rats (0.4 +/- 0.1) but greatly reduced compared with obese nondiabetic rats (18.7 +/- 4.0 ng/ml). Acarbose treatment significantly reduced fasting glucose levels to 13.4 +/- 1.4 mM, while insulin levels increased to 1.6 +/- 0.3 ng/ml. GLUT-4 protein levels in diabetic ZDF rats were reduced approximately 40% in red quadriceps and mixed gastrocnemius muscles but were unchanged in white quadriceps muscle. Acarbose treatment was associated with a twofold increase in GLUT-4 protein and mRNA in mixed gastrocnemius muscle. These data indicate that, in this obese model of NIDDM without hyperinsulinemia, there is reduced muscle GLUT-4 protein in red but not white muscle fiber types. The decrease in muscle GLUT-4 expression in this model of NIDDM can be prevented by acarbose treatment, which reduces hyperglycemia and increases beta-cell responsiveness.
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PMID:Altered expression of muscle glucose transporter GLUT-4 in diabetic fatty Zucker rats (ZDF/Drt-fa). 176 39

To determine the antidiabetic mechanism of Bakumondo-inshi (BI), we examined its effects on glucose absorption, alpha-glucosidase activity, sodium-dependent glucose transporter and facilitative glucose transporter isoform 5 (GLUT5) in small intestine. The oral administration of BI into KK-Ay mice caused a significant decrease in the glucose absorption in small intestine. The small intestine content of active glucose transporter isoform (SGLUT) protein content from KK-Ay mouse significantly decreased in the BI-treated KK-Ay mice compared to that in the controls. However, the small intestine content of facilitative glucose transporter isoform, GLUT5 protein content did not change. The alpha-glucosidase activity in small intestine significantly decreased in the BI-treated KK-Ay mice. These results suggest that the antidiabetic effect of BI is derived, at least in part, from a decrease of glucose absorption in small intestine , due to the reduction of SGLUT protein content in total membrane of the small intestine and the reduction of alpha-glucosidase activity. Because of its therapeutic mechanism, BI could be a new category of therapeutic agent for non-insulin dependent diabetic mellitus.
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PMID:Antidiabetic mechanism of Bakumondo-inshi. 1032 59

Safety factors are defined as ratios of biological capacities to prevailing natural loads. We measured the safety factor of the mouse intestinal brush-border hydrolase maltase in series with the glucose transporter SGLT1, for comparison with previous studies of sucrase and lactase. Dietary maltose loads increased 4-fold from virgin to lactating mice. As in previous studies of intestinal adaptive regulation, that increase in load without change in dietary composition resulted in an increase in maltase and SGLT1 capacities mediated non-specifically by an increase in intestinal mass, without change in maltase or SGLT1 activities per milligram of tissue. Maltase and SGLT1 capacities increased only sublinearly with load during lactation, such that safety factors decreased with load: from 6.5 to 2.4 for maltase, and from 1.1 to 0.5 for SGLT1. The apparently high safety factor for maltase may be related to the multiple natural substrates hydrolysed by the multiple sites of maltase activity. The apparently low safety factor for SGLT1 is made possible by the contribution of hindgut fermentation to carbohydrate digestion. SGLT1 activity is paradoxically higher for mice consuming sucrose than for mice consuming maltose, despite maltose hydrolysis yielding double the glucose load yielded by sucrose hydrolysis, and despite glucose constituting the load upon SGLT1.
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PMID:Loads, capacities and safety factors of maltase and the glucose transporter SGLT1 in mouse intestinal brush border. 1212 47

Maturation of gastrointestinal (GI) function in neonates is stimulated by enteral nutrition, whereas parenteral nutrition induces GI atrophy and malfunction. We investigated whether preterm birth alters the GI responses to parenteral and enteral nutrition. Pigs were delivered either preterm (107 d gestation) or at term (115 d gestation) and fed total parenteral nutrition (TPN) or enteral sow's milk (ENT) for 6 d after birth. Immaturity of the preterm pigs was documented by reduced blood pH, oxygen saturation and neutrophil granulocyte function, impaired intestinal immunoglobulin G uptake from colostrum, and altered relative weights of visceral organs (small intestine, liver, spleen, pancreas, and adrenals). For both ages at delivery, increases occurred in pancreatic weight (30-75%) and amylase activity (0.5- to 13-fold) after birth, but much more in ENT than in TPN pigs (P < 0.05). Six days of TPN feeding was associated with reduced intestinal weight for both delivery groups (60% of values in ENT, P < 0.001), but only in term TPN pigs was the weight lower than at birth (-20%, P < 0.05). Likewise, it was only in term TPN pigs that intestinal maltase activity increased, compared with ENT, and the absorption of glucose and proline decreased. Only in preterm pigs did TPN feeding increase lactase activity (+50% compared with ENT, P < 0.05). For both delivery ages, the mRNA of lactase-phloridzin hydrolase and sodium-coupled glucose transporter 1 were increased in TPN, compared with ENT. In conclusion, the trophic effect of enteral vs. parenteral nutrition on the GI tract is also present after preterm birth, but the postnatal maturation of many GI functions is modified, compared with term birth. The effects of nutritional regimen on the maturation of the gut epithelium in neonates depend on gestational age at birth.
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PMID:Preterm birth affects the intestinal response to parenteral and enteral nutrition in newborn pigs. 1249 87

Maturation of gastrointestinal (GI) function in neonates is stimulated by enteral nutrition, whereas parenteral nutrition induces GI atrophy and malfunction. We investigated whether preterm birth alters the GI responses to parenteral and enteral nutrition. Pigs were delivered either preterm (107 d gestation) or at term (115 d gestation) and fed total parenteral nutrition (TPN) or enteral sow's milk (ENT) for 6 d after birth. Immaturity of the preterm pigs was documented by reduced blood pH, oxygen saturation and neutrophil granulocyte function, impaired intestinal immunoglobulin G uptake from colostrum, and altered relative weights of visceral organs (small intestine, liver, spleen, pancreas, and adrenals). For both ages at delivery, increases occurred in pancreatic weight (30-75%) and amylase activity (0.5- to 13-fold) after birth, but much more in ENT than in TPN pigs (P < 0.05). Six days of TPN feeding was associated with reduced intestinal weight for both delivery groups (60% of values in ENT, P < 0.001), but only in term TPN pigs was the weight lower than at birth (-20%, P < 0.05). Likewise, it was only in term TPN pigs that intestinal maltase activity increased, compared with ENT, and the absorption of glucose and proline decreased. Only in preterm pigs did TPN feeding increase lactase activity (+50% compared with ENT, P < 0.05). For both delivery ages, the mRNA of lactase-phloridzin hydrolase and sodium-coupled glucose transporter 1 (SGLT-1) were increased in TPN, compared with ENT. In conclusion, the trophic effect of enteral vs. parenteral nutrition on the GI tract is also present after preterm birth, but the postnatal maturation of many GI functions is modified, compared with term birth. The effects of nutritional regimen on the maturation of the gut epithelium in neonates depend on gestational age at birth.
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PMID:Preterm birth affects the intestinal response to parenteral and enteral nutrition in newborn pigs. 1222 Dec 28

The rapid development of the gastrointestinal tract posthatch has been described; however, little information exists concerning the development of the small intestine in the prehatch period. The present study examined the morphological, cellular, and molecular changes occurring in the small intestine toward the end of the incubation period by examining the expression of intestinal genes that code for brush border digestive enzymes and transporters, their biochemical activities, and the morphological changes in the mucosal layer. The results indicated that during the last 3 d of incubation the weight of the intestine, as a proportion of embryo weight, increased from approximately 1% on d 17 of embryonic age to 3.5% at hatch. At this time the villi could be divided into two main developmental stages, differing in their length and shape, with the larger villi often being pear-shaped and the smaller villi being narrower and having a rocket-like shape. However, on d 19 a further stage of villus development was observed. Activities of maltase, aminopeptidase, sodium-glucose transporter (SGLT)-1, and ATPase began to increase on d 19 and further increased on the day of hatch. The expression of mRNA for these brush-border membrane (BBM) enzymes and transporters was detected from d 15. Determining quantities relative to beta-actin indicated that expression of all parameters examined was low on d 15 and 17, increased 9- to 25-fold on d 19, and all decreased again on the day of hatch. Relative expression of mRNA of the different enzymes and transporters were correlated as were their activities (r = 0.75 to 0.96); however, expression was not correlated with enzymatic activities. The role of these parameters in the ontogeny of absorption is discussed. Thus, major changes in the expression and localization of the functional brush-border proteins prepare the framework for ingestion of carbohydrate- and protein-rich exogenous feed posthatch.
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PMID:Morphological, molecular, and functional changes in the chicken small intestine of the late-term embryo. 1465 69

Most animals adapt readily to increased supplies of carbohydrate in the intestinal lumen by increasing enzymes for degradation and increasing glucose transporter activity. However, the extent of upregulation of Na+-dependent glucose cotransporter 1 (SGLT1) activity and content in response to increased delivery of carbohydrate to the small intestinal lumen of ruminants is unclear. Therefore, an experiment was conducted to determine the effect of glucose and starch hydrolysate on the activity and abundance of SGLT1 in the small intestine of steers. In a randomized complete block design, 40 crossbred beef steers (243+/-2 kg BW) were fed 0.163 Mcal of ME/(kg BW0.75(d; W), 0.215 Mcal of ME/(kg BW0.75 x d; 2M), or 0.163 Mcal ME/(kg BW0.75 x d) and infused for 35 d into the rumen (R) or abomasum (A) with 12.6 g/(kg BW0.75 x d) of starch hydrolysate (S) or into the abomasum with 14.4 g/(kg BW0.75 x d) of glucose (G). Steers were slaughtered, and brush-border membrane vesicles were prepared from the small intestinal samples obtained from five equidistant sites along the intestine. Maltase activity in vesicles and homogenates differed with intestinal sampling site (quadratic, P < 0.001). Steers on the AG treatment yielded a greater intestinal maltase activity (38 nmol glucose x mg protein(-1) x min(-1)) compared with the AS, RS, W, or 2M treatments (34, 26, 23, and 23 nmol glucose x mg protein(-1) x min(-1) respectively [SEM = 3; P = 0.02]). Sodium-dependent glucose uptake averaged 18.4+/-3.94 pmol glucose/(mg protein x s) and was not affected by treatment, but uptake decreased distally along the intestine (P < 0.001). There was no effect of treatment on SGLT1 protein abundance, but SGLT1 protein abundance increased linearly from the duodenum to the ileum (P = 0.05). The inverse relationship between glucose uptake and SGLT1 abundance suggests that the regulation of brush border Na+-dependent glucose transport capacity is complex, involving factors other than the presence of luminal carbohydrate.
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PMID:Influence of abomasal carbohydrates on small intestinal sodium-dependent glucose cotransporter activity and abundance in steers. 1548 54

Siboglinid worms live on carbohydrates produced by symbiotic bacteria. In this study, alpha-glucosidase-like activity was detected in the surface of the body and in the trophosome of Oligobrachia mashikoi. The enzyme exhibiting this activity was partially purified by consecutively applying the crude enzyme extract to Con-A-Sepharose and Sephadex-200 HR columns. The enzyme sample thus obtained gave a single activity peak at a position corresponding to 550 kDa in the Sephadex-200 HR gel filtration column. The enzyme was active in the range of pH 6.0-8.0, with a maximum activity at around pH 6.5. It specifically hydrolyzed maltose, and was inhibited by voglibose and miglitol. Moreover, a glucose transporter 2-like protein was detected by immunohistochemical and Western-blotting analyses using anti-rat GLUT2 polyclonal antibody. These results raise the question how this unique species lives.
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PMID:Alpha-glucosidase-like activity detected in a siboglinid polychaete, Oligobrachia mashikoi. 1845 18

Twenty-four 21-d-old Arbor Acres (AA) broilers with similar BW were randomly assigned into 4 groups to investigate the effects of stress on the absorption of glucose in the intestine of broilers and its mechanisms. In this study, dexamethasone (DEX), an analog to glucocorticoid secreted when animals suffer from stress, was chosen to simulate the effects of glucocorticoid. Broilers were injected subcutaneously with 0, 0.1, 1, or 5 mg of DEX/kg of BW into the abdomen for 7 d. To explain the nonspecific regulation of glucocorticoid on glucose transport of the jejunum in broilers, the effects of DEX on the jejunum mucosa morphology and disaccharidase activities in broilers were investigated. The results showed that DEX restrained the growth of broilers, and the extent of restraint increased with the increase of the dose of DEX (P<0.05). However, the activities of sucrase and maltase in the jejunum of the broilers injected with DEX were not different from those of the control broilers (P>0.05). In addition, DEX increased the crypt depth of jejunum in broilers, and decreased the villus height, absorption area, and villus height/crypt depth ratio significantly (P<0.05), whereas DEX had no significant effect on villus width and the thickness of mucosa lamina propria (P>0.05). To clarify the specific regulation of glucocorticoid on the glucose transport of jejunum in broilers, the absorption of glucose by jejunum brush border membrane vesicles (BBMV) was investigated, and the expression of Na+-dependent glucose transporter (SGLT1) mRNA was detected by real-time PCR. The results showed that DEX significantly inhibited the glucose absorption of jejunum BBMV (P<0.05), and the extent of inhibition depended on the dose of DEX. In addition, DEX decreased the expression of SGLT1 mRNA significantly (P<0.05). According to these data, we concluded that DEX restrains the glucose transport of jejunum in broilers through nonspecific and specific regulations.
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PMID:Effects of stress simulated by dexamethasone on jejunal glucose transport in broilers. 1915 48

The effects of feed restriction and subsequent refeeding on the gene expression of intestinal enzymes and nutrient transporters at 2 ages, 7 and 35 d, were examined in different groups of broiler chickens. At each age, birds were feed restricted for 7 d (30% of ad libitum intake) followed by 3 d of refeeding ad libitum. Control groups were fed ad libitum. Total RNA of jejunal mucosa was extracted according to the Trizol protocol, and mRNA expression of sodium glucose transporter 1, glucose transporter 2, peptide transporter 1, aminopeptidase, maltase, and sucrase-isomaltase complex was obtained by reverse-transcription PCR. The expression of aminopeptidase, sodium glucose transporter 1, and peptide transporter 1 was higher in feed-restricted groups than in control groups at d 14 (181.4, 116.7, and 80.4%, respectively) and d 42 (143.5, 84.2, and 195.9%, respectively). The mRNA abundance of sucrase-isomaltase complex was higher (159.1%) only in chickens that were feed restricted from d 35 to 42. No statistically significant effect of feed restriction was observed for mRNA abundance of maltase and glucose transporter 2 at either age. After refeeding (d 17 and 45), the RNA abundance of enzymes and nutrient transporters was similar to that in the control group. Thus, this study suggests that an effect of upregulation in gene expression exists during feed restriction that disappears when feed is supplied ad libitum.
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PMID:Messenger ribonucleic acid abundance of intestinal enzymes and transporters in feed-restricted and refed chickens at different ages. 2140 73


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