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 of glucocorticoids (hydrocortisone, dexamethasone) and insulin on enzymatic activities of the intestinal brush border membrane were investigated in an anuran amphibian, Alytes obstetricians, before and during experimental metamorphosis produced by immersion into a thyroxine solution. During experimental metamorphosis, a new epithelium (secondary epithelium) replaces the degenerating primary epithelium. The enzymes studied were three glucidases (maltase, glucoamylase, trehalase) and alkaline phosphatase. In tadpoles reaching the end of premetamorphosis, hormones were injected every day (hydrocortisone, dexamethasone: 25 micrograms/g body wt/day; insulin: 5 mU/g body wt/day, for 3 and occasionally 6 consecutive days. Under such conditions, most of the activities in the primary epithelium increased or remained stable. In animals which completed experimental metamorphosis, the secondary epithelium formed. Hydrocortisone (25 micrograms/g body wt/day) and insulin (5 mU/g body wt/day) treatments significantly decreased the enzymatic activities of the new brush border membrane in animals which received one hydrocortisone and/or insulin injection per day, during 3 consecutive days. Such results, which previously had not been obtained systematically in spontaneously metamorphosing tadpoles (El Maraghi-Ater, Mesnard, and Hourdry (1986). Gen. Comp. Endocrinol. 61, 53-63), emphasize the relative independence of the intestinal metabolism during experimental and spontaneous metamorphosis.
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PMID:Hormonal control of the intestinal brush border enzyme activities in developing anuran amphibians. II. Effects of glucocorticoids and insulin during experimental metamorphosis. 310 33

The effect of streptozotocin (SZ) on the development of small intestinal enzymes in postnatal rat pups was studied. SZ was injected ip on Day 10 and, if necessary, again on Day 12. On Days 15, 18, and 21, one pup from each group (including a vehicle-injected control (C) group) was decapitated under conditions which minimized stress. Plasma glucose, insulin (IRI), and corticosterone were measured, as were pancreatic IRI, liver glycogen, and liver membrane binding of IRI. Small intestinal segments were processed and analyzed for sucrase, lactase, maltase, and ileal acid beta-galactosidase activities. Our results indicate that plasma glucocorticoid levels remained virtually constant in both SZ and C groups, while the ontogenic profiles of sucrase and maltase in SZ rats were shifted toward an earlier appearance and a precocious maturation. Circulating levels of IRI were not reduced significantly by SZ despite the fact that pancreatic IRI was decreased 95%. Jejunal lactase, unlike data reported for diabetic rats, was not affected by SZ diabetes. Also, acid beta-galactosidase was unaltered in the SZ rat pups. It is concluded that possibly the elevated disaccharidases seen in diabetic postnatal rat pups are the direct effect of elevated blood glucose. If so, the SZ rat pup model may be a useful tool with which to study effects of glucose on intestinal enzymes in the absence of changes in plasma insulin.
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PMID:Effects of diabetes on development of small intestinal enzymes of infant rats. 312 20

Alpha-glucosidase inhibitors delay carbohydrate absorption. In order to study the effects of two new alpha-glucosidase inhibitors with long (BAYo1248) and short (BAYm1099) duration of action on glycaemic control, seventeen insulin-dependent diabetics were connected to the Biostator for 24 h and postprandial hyperglycaemia, insulin requirements and breath H2 concentrations were assessed under three conditions: (a) before administration of any alpha-glucosidase inhibitor (control experiments), (b) after administration of BAYo1248 (40 mg before breakfast, nine patients) or BAYm1099 (100 mg before breakfast and dinner, eight patients) for 1 month, (c) after 1-month administration of placebo (double-blind crossover study). All patients were on standard diets (30 kcal kg-1, 45% carbohydrate, 35% fat, 20% protein). BAYo1248 reduced postprandial hyperglycaemia and insulin requirements (vs. values in control and placebo experiments) after breakfast (124 +/- 8 vs. 159 +/- 8 and 158 +/- 8 mg dl-1, 16 +/- 2 vs. 24 +/- 4 and 23 +/- 3 units, P less than 0.01) and lunch (138 +/- 7 vs. 155 +/- 11 and 162 +/- 13 mg dl-1, 19 +/- 3 vs. 24 +/- 3 and 23 +/- 3 units, P less than 0.01) whereas BAYm1099 reduced postprandial hyperglycaemia and insulin requirements after breakfast (127 +/- 4 vs. 167 +/- 12 and 159 +/- 6 mg dl-1, 15 +/- 3 vs. 24 +/- 4 and 21 +/- 3 units, P less than 0.02) and dinner (128 +/- 4 vs. 169 +/- 7 and 157 +/- 10 mg dl-1, 19 +/- 2 vs. 28 +/- 3 and 25 +/- 2 units, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of prolonged administration of two new alpha-glucosidase inhibitors on blood glucose control, insulin requirements and breath hydrogen excretion in patients with insulin-dependent diabetes mellitus. 313 Feb 57

The effects of several hormones on intestinal brush border membrane enzymatic activities have been investigated in intestinal explants taken from the amphibian midwife toad at different developmental stages. Explants were treated for at least 2 days with thyroxine (0.1 microgram/ml of culture medium) or for 2 days with cortisol (25 micrograms/ml) or insulin (6 mU/ml). The hydrolases examined were maltase, trehalase, glucoamylase, and alkaline phosphatase. In the explants from tadpoles in prometamorphosis, thyroxine had no effect on hydrolase activities; cortisol increased the activity of only glucoamylase, and insulin increased activity of maltase, glucoamylase, and alkaline phosphatase. When the explants were taken from tadpoles at the beginning of climax, cortisol and insulin generally stimulated the enzyme activities studied. When taken from tadpoles at the end of climax, at the moment when the embryonic cells under the degenerating epithelium divide, cortisol and insulin had little effect on these activities. When the animals terminate their metamorphosis, the intestinal epithelium of the explants is totally newly formed (secondary epithelium). At this time, cortisol stimulated the activities of maltase, glucoamylase, and alkaline phosphatase, while insulin decreased the activities of maltase and glucoamylase.
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PMID:In vitro study of the intestinal brush border enzyme activities in developing anuran amphibian: effects of thyroxine, cortisol, and insulin. 313 Apr 58

Insulin has been proposed as an important factor in the regulation of growth and differentiation of the small intestine. In the newborn miniature pig, we induced significant physiologic increases in serum insulin and the insulin/glucagon ratio without altering serum glucose, beta-hydroxybutyrate, glucagon, cortisol, T3, and T4 using glucose-based total parenteral nutrition (TPN) in one group (group G) compared with a combination of glucose and fat in another group (group G/F). Control animals were sham-operated and fed a pelleted diet (group OC). Duodenal villus surface area and mucosal height were significantly greater in group G/F compared with group G. No other differences between the TPN groups were found in small intestinal growth, mucosal protein, deoxyribonucleic acid and ribonucleic acid content, and disaccharidase activities. As anticipated, group OC demonstrated increased intestinal length, weight, and villous surface area compared with the TPN groups. Ileal sucrase and jejunal and ileal maltase activities were greater in the TPN groups compared with those in group OC. Physiologic changes in serum insulin and the insulin/glucagon ratio induced by the TPN fuel mix do not appear to have altered small intestinal growth, composition, and differentiation in the healthy small intestine.
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PMID:Effect of different total parenteral nutrition fuel mixes on small intestinal growth and differentiation in the infant miniature pig. 249 81

The influence of insulin on the postnatal development of intestinal functions linked to villus cells (sucrase, lactase, maltase and aminopeptidase) and crypt cells (secretory component of immunoglobulins, SC) has been studied in suckling and weanling rats. At 9 days of age, the animals received a daily injection of insulin 12.5 mU g-1 body weight day-1 for 4 days. Compared with saline-treated controls, insulin had no effect on the development of the intestinal mucosal mass parameters determined in the jejunum, ileum and colon. A premature appearance of sucrase was noted in isolated jejunal villus and crypt cells, the level of activity reached by the enzyme being dependent of the amount of insulin injected. By 6 and 12 h after a single injection of the hormone (12.5 mU g-1 body weight), sucrase activity was detected in all the cell fractions along the villus-crypt axis. In villus cells of insulin-treated rats, maltase, lactase and aminopeptidase activities were significantly (P less than 0.001) increased (+201%, +50%, +207%, respectively, vs. controls), whereas the concentration of SC measured by a sensitive immunoradiometric assay was enhanced over the controls by 75% in villus cells, 83% in crypt cells and 172% in the liver. Weanling rats treated from day 10 to day 20 postpartum with 12.5 mU insulin also exhibited a higher intestinal production of SC (+93%, P less than 0.01) than did saline controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Intestinal development in the suckling rat: effect of insulin on the maturation of villus and crypt cell functions. 313 25

The delay in glucose absorption at the intestinal level obtained with the administration of alpha-glucosidase inhibitors may contribute to an improved metabolic control in diabetic patients. We have examined the effects of two new compounds, BAY m 1099 (short acting) and BAY o 1248 (long acting), on the postprandial glycemic changes, the insulin requirements and the meal-induced hormone responses in nine insulin-dependent diabetics (IDD). The investigation was conducted according to a protocol in which medication and placebo were administered in a double-blind randomized manner. Twelve hours before each experimental day, the patients were connected to the Biostator GCIIS (Ames-Miles) to maintain stabilized normoglycemic levels for the whole period of study. The results showed that: (1) BAY m 1099 decreased the 4-h postprandial glycemic excursions compared to placebo both at dinner and breakfast (P less than 0.05), (2) BAY o 1248 when compared with placebo showed a significant lowering of the peak glycemic levels at breakfast (P less than 0.001) and at lunch (P less than 0.0025), (3) the 2-h and 4-h post-breakfast insulin requirements fell significantly after either drug (P less than 0.02), (4) the plasma levels of contrainsular hormones were not affected by drugs or placebo at any time during the period of study, and (5) no side effects with either drug could be detected. We conclude from our study that both drugs may be useful adjuncts to insulin therapy in insulin-dependent diabetics by reducing postprandial glycemic fluctuations as well as by decreasing insulin requirements with no modification of the meal-induced hormone responses.
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PMID:Effect of two new alpha-glucosidase inhibitors in insulin-dependent diabetic patients. 327 27

The effect of acarbose, an alpha-glucosidase inhibitor, on glycaemic control, was compared with placebo in a double-blind, randomised, group comparison study during 16 weeks in 20 non-obese non-insulin dependent diabetic patients in whom sulphonylurea treatment had been withdrawn. There was significant deterioration in glycaemic control as assessed by HbA1 following withdrawal of the sulphonylurea. There was no significant improvement in HbA1 between weeks 0 and 16 in either the acarbose (11.3% and 12.4% respectively) or the placebo group (10.6% and 12.2% respectively). In both the acarbose and placebo treated groups fasting glucose and insulin concentrations were unaltered. This study also suggests that acarbose was not an effective substitute for sulphonylureas in non-obese Type 2 diabetes uncontrolled by diet alone.
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PMID:Effectiveness of acarbose, an alpha-glucosidase inhibitor, in uncontrolled non-obese non-insulin dependent diabetes. 328 95

Bay-m-1099, a new alpha-glucosidase inhibitor, was given along with insulin immediately before standard breakfasts, lunches and dinners to nine insulin-dependent diabetic patients to determine whether this combination therapy would produce postprandial glycemic control comparable to that achieved when insulin alone was administered 30 min prior to eating. To avoid potential hypoglycemia, 20% less insulin (0.12 vs. 0.15 U/kg) was given with Bay-m-1099. Despite plasma free insulin concentrations which were less than those observed when insulin alone was given (9.4 +/- 1.0 vs. 12.8 +/- 1.6 microU/ml/min, area under curves for all meals), postprandial hyperglycemia (area under curve) was not significantly different (P greater than 0.1) when insulin plus Bay-m-1099 was administered immediately before each meal (124 +/- 26 mg/ml/min) than when insulin was administered 30 min before each meal (113 +/- 17 mg/ml/min). Thus, the combination of immediate preprandial administration of an alpha-glucosidase inhibitor along with insulin resulted in glycemic control comparable to that achieved when more insulin was taken 30 min prior to eating. We conclude that use of alpha-glucosidase inhibitors could lessen the inconvenience of intensive insulin regimens by permitting patients to take their insulin immediately before eating and thus result in greater patient compliance.
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PMID:Alpha-glucosidase inhibition and timing of preprandial insulin in patients with insulin-dependent diabetes mellitus (IDDM). 328 68

Acarbose delays the production of monosaccharides (notably glucose) by inhibiting the alpha-glucosidases associated with the brush-border membrane of the small intestine which are responsible for the digestion of complex polysaccharides and sucrose. In healthy subjects acarbose 100 to 200 mg significantly inhibits postprandial glucose, insulin and triglyceride responses, with some evidence of carbohydrate malabsorption with the higher dose. Clinical trials in patients with non-insulin-dependent diabetes mellitus showed that acarbose improved diabetic control, especially postprandial blood glucose levels, independent of whether the patients were receiving concomitant oral antidiabetic drugs in addition to dietary management. In comparative studies acarbose was significantly superior to placebo, and comparable to biguanides, when used alone or as an adjuvant to sulphonylurea therapy. Trials in patients requiring insulin to control their diabetes demonstrated that acarbose significantly reduced postprandial blood glucose concentrations, resulting in a smoother diurnal blood glucose-time curve and improved symptoms associated with nocturnal hypoglycaemia. Daily insulin requirements were sometimes reduced. In large multicentre trials acarbose up to 600 mg/day for 3 to 12 months improved glycaemic control in approximately 55% of patients with non-insulin-dependent or insulin-dependent diabetes mellitus. Apart from its use in diabetes, encouraging preliminary results have been obtained with acarbose in other therapeutic areas such as dumping syndrome, reactive hypoglycaemia, and types IIb and IV hyperlipoproteinaemias--however, further clinical experience is needed in these settings before clear conclusions can be drawn. No serious side effects have been reported during treatment with acarbose, although it is associated with a high incidence of troublesome gastrointestinal symptoms such as flatulence, abdominal distension, borborygmus and diarrhoea. The incidence of these reactions usually decreases with time. Thus, acarbose represents the first of a new class of oral antidiabetic drugs--the alpha-glucosidase inhibitors. It has proven useful for improving glycaemic control when used as an adjunct to standard therapy involving dietary restriction, oral antidiabetic drugs and/or subcutaneous insulin. That being the case, acarbose should provide the clinician with an interesting treatment option which can be used in a broad range of patients with diabetes mellitus in whom 'traditional' management approaches produce suboptimal glycaemic control.
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PMID:Acarbose. A preliminary review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential. 328 12


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