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)

Glucose and insulin responses to a standardized test meal in patients with chronic duodenal ulceration were measured pre-operatively and again post-operatively. An abnormal pre-operative glucose tolerance contributes to an even more deranged post-operative glucose tolerance. However, following administration of an alpha-glucosidase inhibitor, Acarbose, these post-operative abnormalities are markedly attenuated.
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PMID:Glucose and insulin levels in duodenal ulcer disease before and after surgery. 635 9

Acarbose, an alpha-glucosidase inhibitor, lowers the glycemic excursion following the ingestion of carbohydrates, in particular, sucrose. This was confirmed with increasing doses of acarbose (0, 50, and 100 mg) and the causes investigated. The absorption of the glucose moiety of sucrose was determined from plasma tracer concentrations when overnight-fasted normal subjects received a 100-g oral sucrose load labeled with sucrose [(1-14C]glucose and a simultaneous intravenous infusion of [3-3H]glucose. As the dose of acarbose given with the sucrose load was increased from 0 to 100 mg, the percentage of the load appearing in the peripheral circulation decreased from 90% to 62%. Malabsorption was confirmed by the appearance of breath hydrogen. Simultaneously, absorption time increased from 243 to 411 min. Maximal glycemic excursions were therefore lowered from 64 to 31 mg/dl. The plasma concentrations of gastric inhibitory polypeptide and insulin decreased with the acarbose dose so that the fractional disappearance rate of glucose also decreased. However, the concentrations of glucagon-like immunoreactivity (GLI) rose, confirming the ileal appearance of malabsorbed sucrose.
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PMID:The effects of an alpha-glucoside hydrolase inhibitor on glycemia and the absorption of sucrose in man determined using a tracer method. 636 57

The catalytic activities of N-acetyl-beta-D-glucosaminidase, beta-galactosidase and alpha-glucosidase in kidney and urine of diabetic rats were investigated in relation to the duration of diabetes, to the degree of constant hyperglycaemia and to the therapeutic control in the early stage of disease. The results suggest that the degree of constant hyperglycaemia and the duration of untreated diabetes are significant determining factors for the course of morphological changes. These changes are manifested as a decrease of the glycosidases in kidney (0.5 to 0.6 time the age-matched controls) and as moderate to severe enzymurias. Daily variation of blood glucose with inadequate insulin Lente therapy caused decreased N-acetyl-beta-D-glucosaminidase and beta-galactosidase activities in kidney as well as enzymuria. Since such changes can be correlated with histologically visible changes in the kidney, the measurement of these enzymes in urine is a simple way of monitoring the development of kidney damage in poorly controlled diabetes. When constant normoglycaemia was maintained for three weeks with insulin Ultralente in diabetic rats with a confirmed decrease of kidney glycosidases, the persisting morphological alteration of the organ was reflected by a urinary output of N-acetyl-beta-D-glucosaminidase.
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PMID:Effect of the degree of hyperglycaemia on the catalytic activities of glycosidases in kidney and urine of diabetic rats. 636 9

The postprandial blood glucose rise after a standard meal in six non-insulin dependent diabetics was significantly lower when acarbose 200 mg was taken together with the meal than without acarbose. Eight weeks acarbose treatment (300 mg), however, did not change fasting blood glucose. The effect of four weeks administration of the alpha-glucosidase inhibitor acarbose (300 mg) on diabetes regulation in another ten non-insulin dependent diabetics was compared with metformin (500 mg) in a double-blind cross-over study. Acarbose lowered postprandial blood glucose level from 11.5 +/- 4.2 to 8.9 +/- 1.8 mmol/l (p less than 0.02) and haemoglobin Alc from 8.1 +/- 1.8 to 7.7 +/- 1.7% (p less than 0.05). Urinary glucose was also decreased. Metformin did not significantly change postprandial blood glucose, haemoglobin A1c and urinary glucose excretion with the prescribed dose. The postprandial blood glucose and haemoglobin A1c after 4 weeks of treatment with acarbose and of metformin did not differ significantly. Side-effects of both drugs were mild and mainly gastrointestinal, but the frequency of side-effects was not different.
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PMID:Acarbose treatment of sulfonylurea-treated non-insulin dependent diabetics. A double-blind cross-over comparison of an alpha-glucosidase inhibitor with metformin. 639 73

Nocturnal hypoglycemia is common in the diabetic patient on twice-daily regular and intermediate (NPH or lente) insulin regimens because intermediate-acting insulins before the main evening meal produce "unopposed" free insulin peaks around 0300 h, food absorption having been completed much earlier. Fourteen insulin-dependent diabetic patients were treated for 6 wk with the alpha-glucosidase inhibitor, acarbose, in a double-blind crossover study to see whether the drug would delay absorption of the evening meal sufficiently to correct the mismatch and prevent nocturnal hypoglycemia. On 200 mg acarbose (six patients), inhibition of carbohydrate digestion was so profound as to lead to midevening hypoglycemia with severe flatulence and abdominal colic. With a smaller dose of 100 mg before the evening meal (eight patients) there was a significant reduction in MAGE and MBG coupled with a clinically significant reduction in midevening and nocturnal hypoglycemic reactions. Alpha-glucosidase inhibition therefore provides a promising new approach to the problem of nocturnal hypoglycemia although a preparation that is safe for long-term clinical use remains to be found.
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PMID:A new approach to the treatment of nocturnal hypoglycemia using alpha-glucosidase inhibition. 640 Jul 9

Fasting reduced small intestinal length. It also decreased mucosal weight, DNA and protein content, and concentrations of enterokinase, maltase, and sucrase in both duodenal and jejunal segments. In contrast, the concentrations of lactase and leucine aminopeptidase were not affected. Concomitantly, serum insulin levels dropped to one-fifth of the control levels while serum glucose concentrations showed a lesser degree of reduction. Glucose supplementation alone raised the serum insulin level, prevented the decrease in DNA content, and showed a protective effect on mucosal protein, mucosal weight, mucosal thickness, and villus height. Glucose also protected the sucrase and maltase concentrations; more significantly for maltase in the jejunal segment. Insulin alone, although it increased the serum insulin level to that found with glucose supplementation alone, had no protective effect on the loss in protein, DNA, and most enzymes except for maltase concentration in the jejunal segment. Addition of insulin to glucose did not modify the glucose effect on the contents of DNA, protein, and concentrations of sucrase and maltase. These results suggest that the glucose effect on the mucosa is not mediated by insulin. In addition, the retention of both maltase and sucrase activities through only glucose supplementation suggests the loss of maltase and sucrase in fasting is due to nutrient rather than specific substrate restriction.
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PMID:Effect of glucose and insulin on small intestinal brush border enzymes in fasted rats. 640 48

We have tested the effectiveness of a commercial starch blocker on the digestion and absorption of dietary carbohydrates in six normal, healthy volunteers. The effectiveness of the starch blocker to attenuate or block the digestion of carbohydrate was assessed against a placebo by the measurement of end tidal breath hydrogen, plasma glucose, and insulin responses to a constant test meal. There were no significant differences in breath hydrogen, or plasma glucose and insulin responses. In vitro enzyme inhibition studies assessed the ability of the brush border enzyme maltase/glucoamylase to degrade starch in the presence of the starch blockers. A highly purified solution of rat and human maltase/glucoamylase was capable of degrading a starch solution, while 40 mM Tris-HCl (a known maltase/glucoamylase inhibitor) completely abolished the enzyme activity. These data challenge the claims that starch blocker preparations are effective in reducing or attenuating the absorption of carbohydrates or calories from a mixed meal. The ineffectiveness in vivo could be explained, in part, by the ability of the brush border enzyme maltase/glucoamylase to hydrolyze starch in the presence of starch blockers.
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PMID:Effects of a commercial starch blocker preparation on carbohydrate digestion and absorption: in vivo and in vitro studies. 641 83

The binding of the lectins concanavalin A (Con A) and wheat germ agglutinin (WGA) to the luminal surface of lung alveolar epithelial cells was compared in normal rats and rats with streptozotocin-induced diabetes and their offspring. Lung tissue was lavaged, then fixed in situ with 3% glutaraldehyde. Buffer-rinsed slices of lung were incubated in Con A, WGA, or various control media. Lectin binding sites were visualized by the use of the peroxidase method. Normal neonates and those that were the results of diabetic pregnancies showed a hexose-specific Con A and WGA binding pattern qualitatively similar to that of normal and diabetic adults, respectively. In the normal animals, Con A binding sites were masked by sialic acid residues and were removable with alpha-mannosidase after neuraminidase treatment. In the diabetic adults and their offspring, one the other hand, Con A binding sites were readily accessible and were totally removed only by sequential treatment with alpha-mannosidase and alpha-glucosidase. WGA binding was essentially eliminated with neuraminidase in all animals except in the neonates from diabetic pregnancies, where N-acetyl-glucosaminidase was also required. The effects of maternal diabetes were reversible and occurred about Day 7 postpartum in the neonate. The effects were also reversible following insulin replacement in the diabetic adult.
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PMID:Diabetic pregnancy. Changes in lectin binding to the surface of rat lung alveolar epithelial cells. 668 9

Acarbose is a newly developed inhibitor of intestinal alpha-glucosidase, and in the current study its ability to lower plasma glucose levels was studied in 12 patients with non-insulin-dependent diabetes mellitus, poorly controlled on diet plus sulfonylurea drugs. Patients were studied before and three months after the addition of acarbose to their treatment program, and there was a notable fall in postprandial plasma glucose concentrations that approximated 60 mg/dL. When acarbose therapy was discontinued in five patients, plasma glucose levels rapidly returned toward pretreatment levels. In addition to the improvement in glycemia, acarbose treatment also led to a notable reduction in Hb A1c and triglyceride concentrations. Finally, considerable individual variation was noted in the response to acarbose, and the results in four patients were quite dramatic, with striking reductions in both fasting and postprandial glucose concentrations. These data suggest that acarbose may be a useful addition in the treatment of patients with non-insulin-dependent diabetes mellitus.
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PMID:Acarbose treatment of non-insulin-dependent diabetes mellitus. 669 73

Jejunal mucosa of 6 d-old rats were cultured for 24 and 48 h in the presence of thyroxine, insulin, pentagastrin, glucagon, epidermal growth factor (EGF) or dibutyryl-A-3:5-MP cyclic with or without dexamethasone (DX). The enzymes were assayed on the purified brush borders. The various agents added alone to the basic culture medium had no effect with the exception of DX on the levels of enzyme activities. Dexamethasone alone induced sucrase, stimulated maltase, and protected other brush border enzyme activities (aminopeptidase, lactase, and alkaline phosphatase). When added to DX-supplemented medium, only the following factors modified the levels of enzymatic activities observed with DX alone. Insulin (10(-6) M) increased maltase, alkaline phosphatase, and lactase activity to a greater extent than DX at 24 h culture, the effect being maintained at 48 h on alkaline phosphatase only. At 48 h culture, both EGF (10(-8) M) and dbcAMP (10(-3) M) decreased DX-induced sucrase activity. The latter agent also depressed DX-stimulated aminopeptidase activity.
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PMID:Organ culture of suckling rat intestine: comparative study of various hormones on brush border enzymes. 674 50


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