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:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synergistic effects of dexamethasone (DEX) and thyroxine (T4) on the postnatal maturation of the 13-d-old rodent small intestine has been studied. Previous studies have shown that hydrocortisone and T4 produced a synergistic response in enzyme maturation. However, T4 elevates corticosteroid-binding globulin, which reduces the clearance of hydrocortisone. Thus, the apparent synergy between T4 and hydrocortisone may have been due to increased glucocorticoid availability. DEX, which does not bind to corticosteroid-binding globulin, was given (d8-12) at 25 pmol (i.e. 0.01 micrograms)/g body wt/d as established by a dose-response study in which this dose of DEX induced one third the maximum response in sucrase activity. In this way, synergy with T4 (130 pmol/g body wt/d, i.e. 0.1 micrograms/g body wt/d, d 5-12) could still be observed. Glucoamylase, lactase, acid beta-galactosidase, alkaline phosphatase, and sucrase activities were determined in two regions of the small intestine. Overall, the results for the two hormones administered alone showed intestinal maturation to be not significantly affected in the T4 group and partially stimulated in the DEX group. When combined, DEX + T4 synergistically increased jejunal sucrase, ileal glucoamylase, and duodenal alkaline phosphatase, and lowered ileal acid beta-galactosidase. The striking exceptions to the general pattern were two brush border enzymes that normally decline during intestinal maturation, namely ileal alkaline phosphatase and jejunal and ileal lactase. For these enzymes, DEX alone did not elicit precocious maturation, and there was no evidence for a synergistic interaction of these two hormones. Serum corticosterone concentrations also were measured. When corticosterone concentrations were compared with enzyme activity, no correlation was found.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Synergistic effects of thyroxine and dexamethasone on enzyme ontogeny in rat small intestine. 140 67

A study was carried out to examine whether the responsiveness of small intestinal epithelial cells to dietary carbohydrate varied during the daily 24 h cycle. The effect of sucrose on disaccharidase activities was compared during a period of decreasing disaccharidase activities, i.e. between 22.00 and 10.00 hours, and increasing disaccharidase activities, i.e. between 10.00 and 22.00 hours, in the jejunum of 7-week-old-rats. Rats were fed on a low-starch, high-fat diet (Lst; starch 5 and fat 73% of gross energy), or a high-starch, low-fat diet (Hst; starch 70 and fat 7% of gross energy). Both dietary groups exhibited typical diurnal variations in jejunal sucrase (EC 3.2.1.48), maltase (EC 3.2.1.20) and lactase (EC 3.2.1.23) activities, exhibiting a peak around 22.00 hours and a trough at approximately 10.00 hours. When rats were fed on diet Lst for 7 d and then force-fed on an isoenergetic sucrose diet (S; sucrose 40 and fat 37% of gross energy) for 6 or 12 h they exhibited increased sucrase, maltase and lactase activities compared with rats fed on diet Lst. The absolute increase in disaccharidase activities was similar regardless of the time diet S was given or whether rats were killed at 10.00 hours or at 22.00 hours. Analyses of sucrase and lactase activities along the villus-crypt columns showed that the distribution of cell cohorts that responded to diet S was not influenced by the time of introduction of diet S. These findings suggest that small intestinal epithelial cells possess the ability to respond to dietary carbohydrate throughout the daily 24 h cycle.
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PMID:Dietary-induced increases of disaccharidase activities in rat jejunum. 159 99

Gastric intubation was adopted to examine the effect of continuous nutrient supply on digestive development of the pig during the immediate post-weaning period. The 14 d-weaned animals were slaughtered at 3, 5 and 7 d post-weaning (3W, 5W and 7W respectively) and the suckled animals were slaughtered at 14 and 22 d of age (14SR and 22SR respectively). The weight of the pancreas (g/kg bodyweight) was significantly greater (P less than 0.05) in the 5W and 7W groups, as was the weight of large intestine (g/kg) in all weaned groups (P less than 0.01) compared with sow-reared pigs. The stomach weight (g/kg) tended to be greater in the weaned groups. Weaning, in conjunction with a continuous nutrient supply, did not significantly alter the time-related changes in the weight of the small intestine (SI) or the SI mucosa, although both variables tended to be lowest in the 3W group. However, there was a 20% reduction in the protein content of the mucosa within the first 3 d post-weaning (P less than 0.01) which persisted during the 7 d experimental period. Lactase, (beta-galactosidase; EC 3.2.1.23) activity (mumol/g protein and mol/d) of the 7W group was reduced to approximately 40% of the 22SR value. Hence, continuous nutrient supply may have delayed, but did not prevent, the loss of lactase activity at weaning. The activity of sucrase (sucrose-alpha-glucosidase; EC 3.2.1.48) was significantly higher in 22SR compared with 14SR animals. Sucrase activity in weaned pigs was intermediate to the values for sow-reared pigs whereas maltase (alpha-glucosidase; EC 3.2.1.20) and glucoamylase (glucan 1,4-alpha-glucosidase; EC 3.2.1.3) were significantly increased in relation to their sow-reared counterparts. Continuous nutrient supply did not prevent the reduction in villous height and the crypt hypertrophy associated with weaning. The results of the present study suggest that there may be some degree of interaction between nutrient intake and gut development during the immediate post-weaning period but that there is also a component of the adaptive response which is independent of nutrient intake. They confirm the rapid substrate induction of the brush-border glucoamylases and indicate the importance of considering total as well as specific enzyme activity for satisfactory interpretation of changes in digestive function.
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PMID:Digestive development of the early-weaned pig. 1. Effect of continuous nutrient supply on the development of the digestive tract and on changes in digestive enzyme activity during the first week post-weaning. 190 70

Gastric intubation was adopted as a means of comparing the effect of two feeding levels, continuous nutrient supply (C) and restricted nutrient supply (R), on the digestive development of pigs weaned at 14 d of age, during the first 5 d post-weaning. The absolute weights of the stomach and the pancreas were significantly greater (P less than 0.001) in C compared with R pigs. The effect was not significant for pancreas weight when expressed per kg body-weight but was significant (P less than 0.05) for stomach weight. The weights of the small intestine (SI), SI mucosa and total mucosal protein were significantly higher (P less than 0.001) in C pigs but protein content per g mucosa was similar in the C and R groups. There was no significant effect of treatment on the activity of lactase (beta-glucosidase; EC 3.2.1.23) or sucrase (sucrose-alpha-glucosidase; EC 3.2.1.48) irrespective of the basis of comparison used. The specific activity (mumol/min per g protein) of maltase (alpha-glucosidase; EC 3.2.1.20) and of glucoamylase (glucan-1,4-alpha-glucosidase; EC 3.2.1.3) were similar in C and R groups but activities of maltase (mumol/g mucosa) (P less than 0.05), and maltase and glucoamylase (mol/d) (P less than 0.01) were significantly higher in C pigs. Villous height and crypt depth were significantly greater in C pigs (P less than 0.001 and P less than 0.05 respectively). Enteroglucagon was significantly (P less than 0.05) higher in C compared with R pigs. Xylose absorption and the digestibility of energy were not affected by treatment. Digestibility of dry matter, organic matter, crude protein (nitrogen x 6.25) and carbohydrate were significantly higher (P less than 0.001, P less than 0.01, P less than 0.05 and P less than 0.001 respectively) in R pigs compared with C pigs but the differences were small, ranging from 1.3 to 2.5%. These results demonstrate that (1) nutrient intake in the weaned pig affects the anatomy, morphology and function of the gut, (2) there is considerable 'spare capacity' for digestion of cereal-based diets even in pigs weaned at 14 d of age, (3) measurements in vitro of digestive function are of limited value unless supported by information in vivo on absorption/digestibility.
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PMID:Digestive development of the early-weaned pig. 2. Effect of level of food intake on digestive enzyme activity during the immediate post-weaning period. 204 2

The aim of the present experiment was to determine the influence of either probiotic or antibiotic inclusion in the diets of pigs from birth on the development of enzyme activity in the small intestine. Pigs were fed on creep feed and grower diets containing either a probiotic, an antibiotic or no added growth promoter. At 7, 17, 42 and 80 d of age pigs from each treatment group were sampled to investigate the development of carbohydrase and peptidase activity in the mucosa at five sites along the small intestine. Inclusion of either the probiotic or antibiotic had a significant effect on the development of sucrase (sucrose alpha-D-glucohydrolase; EC 3.2.1.48), lactase (beta-D-galactoside galactohydrolase; EC 3.2.1.23) and tripeptidase (EC 3.4.11.4) activities before weaning but had no effect on depeptidase (EC 3.14.13.11) activity. The study of the distribution of enzyme activity along the small intestine showed significant differences between the proximal and distal sections associated with weaning.
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PMID:The influence of inclusion of either an antibiotic or a probiotic in the diet on the development of digestive enzyme activity in the pig. 211 23

Adult rats that were maintained on a low-carbohydrate intake showed rapid increase in the activities of sucrase, maltase, and lactase along the length of the small intestine when they were fed a high-starch diet. In the present study, we have identified these activity increases, and showed that they reflect proportional accumulations in enzyme-protein of sucrase-isomaltase (EC 3.2.1.10, 3.2.1.48), maltase-glucoamylase (EC 3.2.1.20), and neutral lactase (EC 3.2.1.23). It was determined that each of these enzymes exists in adult rat intestine in single immunoreactive form and accounts as a group for all sucrase, cellobiase, and most maltase and lactase activities. Dietary change from low to high carbohydrate (starch) resulted in an increase in [3H]leucine accumulation in each of the enzymes, without a change in the amount of label accumulation in total intestinal proteins. The increase in label accumulation in the brush-border carbohydrase pools was matched generally by proportional elevation in the pool concentrations of sucrase-isomaltase and lactase but not maltase. These studies suggest that the elevation of intestinal carbohydrase concentrations induced by high-carbohydrate feeding may involve selective stimulation of their synthesis.
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PMID:Nature of elevated rat intestinal carbohydrase activities after high-carbohydrate diet feeding. 241 70

Adult rats when fed a high carbohydrate diet of 70% sucrose or glucose for 24 h following a 4-day fast showed increased concentrations of intestinal sucrase-isomaltase (EC 3.2.1.48, EC 3.2.1.10) and maltase-glucoamylase (EC 3.2.1.20) but not lactase-phlorizin hydrolase (EC 3.2.1.23, EC 3.2.1.62). The concentration increases of these enzymes were accompanied by corresponding acceleration of their synthesis rates. Contrary to earlier studies by others, suggesting that upper villus cells in the fasted intestine are unresponsive to stimulation of sucrase activity by refeeding a high-sucrose diet, the concentration increases of both sucrase-isomaltase and maltase-glucoamylase were seen to occur in cells all along the length of the villus column. The earlier studies differed from the present study by basing enzyme assays relative to protein rather than the DNA content of villus cell fractions. We have shown that villus cells increase their protein content severalfold while migrating to villus tip, providing the basis for the difference between earlier and the present findings. Further evidence that stimulation of sucrase-isomaltase and maltase-glucoamylase by high carbohydrate is not restricted to the crypt and lower villus region was obtained by the finding that their synthesis rates appeared to be equally stimulated along the length of the villus column.
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PMID:Dietary CHO and stimulation of carbohydrases along villus column of fasted rat jejunum. 249 55

Small-intestinal disaccharidase activities of eight suckling T. vulpecula, aged from 34 to 150 days, and of two adult animals were investigated. Intestinal maltase, isomaltase and sucrase activities increased with age, whereas lactase activities decreased. Trehalase activities were relatively high in all animals and showed no obvious age-related changes. Three separate beta-galactosidase activities, one neutral and two acid, acted on lactose. The neutral beta-galactosidase activity appeared to be due to a brush border enzyme similar to that of eutherian mammals, whereas the acid beta-galactosidases were soluble and probably of lysosomal origin. One of these, acid beta-galactosidase-1, had similar properties to the sole intestinal beta-galactosidase of macropodid marsupials, whereas the other, acid beta-galactosidase-2, has not previously been described. Galactosyl oligosaccharides isolated from macropodid milk were readily hydrolysed by both acid beta-galactosidases but not by the neutral beta-galactosidase. The total intestinal lactase activity in animals aged up to 125 days was due mainly to acid beta-galactosidase-1, whereas in older animals it was due mostly to the neutral beta-galactosidase; this suggests that late in lactation the young T. vulpecula change from a macropodid mode of digestion of galactosyl oligosaccharides to a eutherian mechanism for the digestion of lactose. These findings may have implications for the hand-rearing of orphaned T. vulpecula.
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PMID:Intestinal lactase (beta-galactosidase) and other disaccharidase activities of suckling and adult common brushtail possums, Trichosurus vulpecula (Marsupialia:Phalangeridae). 251 66

The inhibitory action and mechanism of inhibition of two types of alpha-glucosidase inhibitors, acarbose (Bay-g-5421) and 1-deoxynojirimycin derivatives (Bay-m-1099 and Bay-o-1248), on small intestinal carbohydrases (sucrase, isomaltase, glucoamylase, trehalase and lactase) and pancreatic alpha-amylase were compared in vitro using small intestinal brush border membranes and pancreatic homogenates from adult Sprague-Dawley rats. Acarbose at a low (4 microM) concentration strongly inhibited the activities of glucoamylase, alpha-amylase and sucrase (98, 68, and 63%, respectively). At a high (200 microM) concentration, isomaltase activity was also inhibited (28%); effects on trehalase and lactase activities were negligible. Both the 1-deoxynojirimycin derivatives were even more potent inhibitors of sucrase (Ki = 8.6 x 10(-8) M for Bay-m-1099;Ki = 5.0 X 10(-8) M for Bay-o-1248) than acarbose (Ki = 9.9 x 10(-7) M). Whereas glucoamylase activity was strongly inhibited by the 1-deoxynojirimycin derivatives, alpha-amylase activity was not. In contrast to acarbose, the 1-deoxynojirimycin derivatives at high concentrations (20-200 microM) inhibited considerably trehalase and lactase (a beta-galactosidase) activities. The inhibition of lactase activity was stronger by Bay-m-1099 (Ki = 4.9 X 10(-6) M) than by Bay-o-1248 (Ki = 6.7 X 10(-5) M). Where inhibition was seen, kinetic analysis showed fully competitive inhibition of sucrase, isomaltase, trehalase, glucoamylase and lactase by all three inhibitors.
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PMID:Inhibitory mechanism of acarbose and 1-deoxynojirimycin derivatives on carbohydrases in rat small intestine. 296 44

To evaluate the response of the small intestinal mucosa to Saccharomyces boulardii (S.b.), a yeast widely used in some countries as an adjuvant drug with oral antimicrobial therapy, seven healthy adult volunteers were treated with high doses of lyophilized S.b. (250 mg four times per day) for 2 wk. A peroral jejunal suction biopsy was performed on days 0 and 15 of the study. Compared to the initial biopsy, histological examination of the posttrial biopsy revealed no morphological alteration nor change in villus height or crypt depth. After treatment, the specific activity (per U protein) of sucrase, lactase, and maltase was, respectively, increased by 82% (p less than 0.05) 77% (p less than 0.05), and 75% (p less than 0.05) over the basal activity of the enzymes measured on day 0, whereas mucosal protein content remained unchanged. Similar findings were found in the jejunum of adult rats treated for 5 days with either viable or killed S.b. cells. The changes in total enzyme activity (per jejunal segment) paralleled the changes in specific enzyme activity. In vitro assays on freshly prepared suspensions of S.b. (6.0 X 10(8) viable cells/ml) evidenced a high activity for sucrase (mean +/- SE: 8 364 +/- 1280 U X g X protein-1) but no maltase, neutral lactase, acid beta-galactosidase, or aminopeptidase activity. To determine whether treatment with S.b. could influence the incorporation rate of neutral lactase into the brush border membrane, 14-day-old sucklings treated either with saline or with S.b. were given intraperitoneally a dose of 20 microCi D-[1(14)C] glucosamine 3 hours before sacrifice.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Response of human and rat small intestinal mucosa to oral administration of Saccharomyces boulardii. 308 Jul 30


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