Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Streptozotocin treatment (125 mg/kg) in the Chinese hamster induced hyperglycaemia, hypoinsulinaemia, hyperglucagonaemia and changes in body, liver, pancreas, stomach, kidney and adipose tissue weights. The pancreatic reserves of insulin and glucagon in the diabetic animals were low, but stomach glucagon high. These animals showed high levels of phosphoenolpyruvate carboxykinase and low levels of glucokinase, hexokinase, isocitrate dehydrogenase and malic enzyme, but normal levels of pyruvate kinase in the liver. Increases in lactate dehydrogenase subunit B and isozymes 2, 3 and 4 were also observed in the liver, but not in the epididymal fat pad, of the diabetic animals. N-Acetyl-beta-D-glucosaminidase was elevated in plasma, liver and heart, but not in the kidney of the treated animals. Renal alpha-galactosidase and beta-glucosidase were depressed, whereas beta-galactosidase and alpha-glucosidase remained essentially normal. These features indicated that there were considerable differences between the biochemical disorders associated with streptozotocin-diabetes in the Chinese hamster and the published observations in the rat.
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PMID:Streptozotocin-induced diabetes in the Chinese hamster. Biochemical and endocrine disorders. 59 Jun 51

The activities of lysosomal maltase in the serum, urine and kidney were determined in rats with diabetes induced by streptozotocin (STZ, 75 mg/kg, i.p.) and compared with the changes in N-acetyl-beta-D-glucosaminidase (NAG) activity. Moreover, effects of insulin on maltase and NAG activities of the serum, urine and kidney in diabetic rats were studied. The following results were obtained: 1) The serum maltase activity within 24 hr after administration of STZ was influenced by insulin secretion. 2) Significant increases in blood urea nitrogen (BUN) levels were observed from the 3rd week after a single administration of STZ. The serum insulin level significantly decreased at 3 weeks after treatment of STZ. In this time, maltase activity in the serum rapidly increased, while the enzyme activity in the kidney decreased considerably. On the other hand, the changes in NAG activities in the serum, urine and kidney after administering STZ were almost similar to those in maltase activities. 3) There were positive relationships between maltase and NAG activities in the serum and urine in diabetic rats, respectively. 4) When lente insulin (2U) was subcutaneously injected once daily for 20 days from 24 hr after administration of STZ, NAG activities in the serum and kidney approached to the control levels. However, maltase activities in the group treated with insulin were significantly higher in the serum and kidney than those in the control group.
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PMID:[Effects of insulin on maltase and N-acetyl-beta-D-glucosaminidase (NAG) activities of serum and kidney in experimental diabetic rats]. 253 Jan 41

Specific and total activities of the disaccharidases, sucrase, maltase, and lactase are increased in mucosa of the small intestine of the streptozotocin diabetic rat. Because disaccharidases are essential for terminal digestion of carbohydrate, and disaccharidase deficiency is a common clinical problem, understanding the mechanisms regulating disaccharidase activity is important. In normal animals, disaccharidase activities are determined by route of feeding and are decreased by parenteral feeding. The indirect exocrine, endocrine, neurocrine, and paracrine functions of the gastrointestinal tract that are dependent on feeding via the gut are greatly decreased in parenteral as compared with enteral feeding. Hormone secretion by the gut and the pattern of response after feeding may be abnormal in diabetes and might be regulatory for disaccharidases. We tested the hypothesis that the elevated intestinal disaccharidases in diabetes are dependent on enteral feeding. Streptozotocin-injected rats (diabetics) and vehicle-injected rats (controls) were fed rat chow ad libitum for 4 days. A subset of control and diabetic animals was then killed to determine disaccharidase activity of the jejunum at the start of pair-feeding the elemental diet. The remaining animals were fed 60 cal/day of glucose, amino acid (Travasol), and electrolyte solution either intragastrically or intravenously for 4 days. Specific and total activities of disaccharidases were greater in diabetics than in controls under all feeding conditions. In controls, the pattern of activity of disaccharidase specific activity was initial greater than intragastric greater than intravenous. In diabetics, disaccharidase specific activities did not differ among groups. In both controls and diabetics, mean mucosal mass was highest initially; intermediate with intragastric feeding; and lowest with intravenous feeding. In both controls and diabetics, total disaccharidases decreased from initial to intragastric to intravenous. We conclude: (1) disaccharidase specific activity in controls is sensitive to feeding route and nature of diet, but is nearly independent of these factors in diabetics; (2) total disaccharidase activities respond to feeding stimuli in parallel with changes in mucosal mass in both controls and diabetics; and (3) the lack of feeding effect on the elevated specific activities of disaccharidases in diabetes suggests that this elevation is a response to the diabetic state and is independent of enteral factors such as luminal nutrition and gastrointestinal hormones.
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PMID:Elevated intestinal disaccharidase activity in the streptozotocin-diabetic rat is independent of enteral feeding. 640 7

Prophylactic insulin treatment prevents the development of hyperglycemia in animal models of insulin-dependent diabetes mellitus. Acarbose is a new antidiabetic drug which improves hyperglycemia by inhibiting alpha-glucosidase. In the present study, we determined the preventive effect of acarbose against multiple low-dose streptozotocin (MLDSTZ)-induced diabetes mellitus. The male ICR mice were fed acarbose (40 mg/100 g) containing powdered chow before the start of STZ administration. The mice were sacrificed at 3 and 10 days after the final STZ injection. MLDSTZ decreased serum immunoreactive insulin (IRI) levels and increased plasma glucose levels. Acarbose administration tended to decrease plasma glucose and serum IRI levels were significantly reduced in vehicle-treated mice. Acarbose administration significantly attenuated the degree of inflammation and destruction in pancreatic islets after MLDSTZ administration. In conclusion, acarbose-induced attenuation of acute hyperglycemia following MLDSTZ partially prevents the severity of pancreatic islet damage.
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PMID:Acarbose partially prevents the development of diabetes mellitus by multiple low-dose streptozotocin administration. 887 71

Summary. Many studies have shown that experimental type 1 diabetes causes morphological, functional, and metabolic alterations in the small intestine. The more frequent form of the disease, type 2 diabetes, however, has been less studied. Here the influence of diabetes on the functionality of the small intestine was studied in an experimental diabetes model, with a certain degree of residual insulin secretion, specifically in the n0-STZ model. - The diabetic rats in this model were found to have glycaemia levels higher than in the controls (8.82 +/- 0.27 and 6.18 +/- 0.18 mmol/L; p < 0.01), while their plasma insulin levels were lower than in the control rats (2.65 +/- 0.32 and 3.60 +/- 0.25 ng/ml; p < 0.05). Although there were no significant variations in body weight between the two groups, both the weight and the length of the intestine were significantly greater (p < 0.05) in the diabetic rats than in the controls. The sucrase and maltase activities were greater (p < 0.01) in the proximal intestine of the diabetic rats (94 +/- 8 and 234 +/- 12 mU/mg protein, respectively) than in the control rats (50 +/- 2 and 149 +/- 20 mU/mg protein, respectively). The 6-phosphofructo-1-kinase activity (mU/mg proteins) was less (p < 0.05) in the proximal and distal intestine of the diabetic rats (160 +/- 40 and 80 +/- 20, respectively) than in the controls (280 +/- 30 and 230 +/- 30, respectively). No significant differences were observed in the lactate dehydrogenase or active and total pyruvate dehydrogenase measured in the distal and proximal intestine of control and diabetic rats. In conclusion, our results show that experimental diabetes (n0-STZ model) similar to human type 2 diabetes produces certain morphological and enzymatic alterations which affect the digestion and absorption of carbohydrates and the intestinal metabolism of glucose. These alterations may contribute to producing the post-prandial hyperglycaemia which characterizes diabetes.
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PMID:Morphological and enzymatic changes of the small intestine in an n0-STZ diabetes rat model. 1201 71

Since ages, botanical substances are in use for the remedy of diabetes with considerable degree of success. One of the such; an extract of Commelina communis L. (CE-L) after decoction in water has been traditionally used for the treatment of diabetes in Korea. However, its action mechanism has not yet been established. To explore the inside of its action-mechanism, in this study, the effect of the aqueous extract of C. communis L. (CE-L) on the activity of alpha-glucosidase was evaluated in vitro and in vivo. Aqueous extract of CE-L showed inhibitory activity of the alpha-glucosidase in a dose-dependent manner, in vitro. CE-L also seems to be by and large free from exerting any cytotoxic effect at least in CHO-K1 fibroblast and 3T3-L1 adipocyte. CE-L alleviated hyperglycemia caused by maltose or starch loading in normal and Streptozotocin (STZ)-induced diabetic mice with better efficacy than that of acarbose. In addition, prolonged administration of CE-L tends to normalize hyperglycemia in STZ-induced diabetic mice. Such results suggest that inhibitory activity of CE-L on alpha-glucosidase may contribute to delay in carbohydrate digestion and glucose absorption. Thus, CE-L has potential for use in the management of non-insulin-dependent diabetes.
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PMID:Anti-hyperglycemic activity of Commelina communis L.: inhibition of alpha-glucosidase. 1556 67

A purified pancreatic alpha-amylase inhibitor (alpha-AI) from white beans (Phaseolus vulgaris) was administered orally (100 mg/kg body weight dissolved in 9 g NaCl/l) for 22 d to non-diabetic (ND) and type 2 diabetic (neonatal diabetes models n0-STZ and n5-STZ) male Wistar rats. Mean glycaemia (mmol/l) declined from day 4 of the alpha-AI administration in ND rats (5.48 (sem 0.08) v. 4.39 (sem 0.13); P<0.05), n0-STZ diabetic rats (7.94 (sem 0.42) v. 5.56 (sem 0.32); P<0.01) and n5-STZ diabetic rats (17.34 (sem 2.58) v. 11.93 (sem 1.96)), until the end of treatment: ND (5.22 (sem 0.21) v. 3.97 (sem 0.06); P<0.01); n0-STZ (8.10 (sem 0.19) v. 5.21 (sem 0.30); P<0.01); and n5-STZ (16.36 (sem 2.14) v. 7.69 (sem 1.34); P<0.01). There was a decrease in water intake (ml/d) in the alpha-AI-treated diabetic rats: n0-STZ (30 (sem 0.10) v. 22 (sem 1.50); P<0.01) and n5-STZ (76 (sem 5.04) v. 57 (sem 4.85); P<0.01). Food intake (g/d) decreased in all three groups: ND (23 (sem 0.31) v. 20 (sem 0.03); P<0.05); n0-STZ (22 (sem 0.55) v. 16 (sem 0.98); P<0.01); and n5-STZ (31 (sem 0.58) v. 23 (sem 1.20); P<0.01). The enterocyte sucrase and maltase activities (U/g proteins) were high (P<0.01) in the untreated diabetic rats, n0-STZ (45 (sem 4) and 152 (sem 10), respectively) and n5-STZ (67 (sem 12) and 151 (sem 10), respectively) with respect to the ND rats (24 (sem 2) and 74 (sem 10), respectively). After alpha-AI treatment, enzyme activities declined in both diabetic rats, n0-STZ (21 (sem 2) and 85 (sem 11); P<0.01) and n5-STZ (28 (sem 7) and 75 (sem 19); P<0.05), to values close to those in the ND rats. In conclusion, alpha-AI significantly reduced glycaemia in both the ND and diabetic animals and reduced the intake of food and water, and normalized the elevated disaccharidase levels of the diabetic rats.
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PMID:White bean amylase inhibitor administered orally reduces glycaemia in type 2 diabetic rats. 1692 60

A screening of 5 plants used for making drinks in Vietnam revealed a Cleistocalyx operculatus (Roxb.) Merr and Perry flower bud extract to have the highest inhibitory activity against the alpha-glucosidase enzyme. The anti-hyperglycemic effects of an aqueous extract from flower buds of Cleistocalyx operculatus (CO), a commonly used material for drink preparation in Vietnam, were therefore investigated in vitro and in vivo. In vitro, the CO extract inhibited the rat-intestinal maltase and sucrase activities, with IC50 values of 0.70 and 0.47 mg/ml, respectively. These values are lower than those for a guava leaf extract (GE; IC50 0.97 and 1.28 mg/ml, respectively). Postprandial blood glucose testing of normal mice and STZ-induced diabetic rats by maltose loading (2 g/kg body weight (bw)) showed that the blood glucose reduction with CO (500 mg/kg bw) was slightly less than that with acarbose (25 mg/kg bw) but was more potent than that with GE (500 mg/kg bw). In an 8-week experiment, the blood glucose level of STZ diabetic rats treated with 500 mg of CO/kg bw/day was markedly decreased in comparison with that of non-treated diabetic rats. Consequently, CO is considered to be a promising material for preventing and treating diabetes.
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PMID:Anti-hyperglycemic activity of an aqueous extract from flower buds of Cleistocalyx operculatus (Roxb.) Merr and Perry. 1721 65

Type 2 diabetes is an endocrine disease, which accounts for 9% of deaths worldwide. The aim of oral therapy is to reach normoglycemia to prevent later complications. Among glucose-lowering medications, alpha-glucosidase inhibitors delay the absorption of ingested carbohydrates, reducing the postprandial glucose and insulin peaks. In the present study, we tested the butanolic extracts of four Mexican plants with respect to their alpha-glucosidase inhibition activity, without excluding other possible mechanisms of action. The plants Cecropia obtusifolia Bertol., Equisetum myriochaetum Schlecht & Cham, Acosmium panamense (Benth.) Yacolev and Malmea depressa (Baill) R.E. Fries are used in traditional medicine to treat type 2 diabetes. In previous studies, we have demonstrated these plants' hypoglycemic activity and determined the phytochemical composition of their extracts. Our results in n-STZ diabetic rats loaded with maltose showed that Malmea and Acosmium extracts decreased plasma glucose significantly from 30 min on resembling the effect of acarbose. Cecropia extract produced the highest reduction of plasma glucose, and at 90 min, the glucose level was lower than the fasting level, which suggests another mechanism of action. Equisetum did not exert any effect. In vitro assays of alpha-glucosidase activity showed an IC(50) of 14 microg/ml for Cecropia, 21 microg/ml for Malmea, and 109 microg/ml for Acosmium, which were lower than that of acarbose (128 microg/ml). Equisetum did not show any significant effect on this assay, either. These results contribute to understand the mechanism of action of these plants on glucose metabolism.
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PMID:Alfa-glucosidase-inhibiting activity of some Mexican plants used in the treatment of type 2 diabetes. 1808 48

Postprandial hyperglycaemia is thought to increase inflammation in leucocytes. In the present study, we examined whether sucrose loading in rats with moderate postprandial hyperglycaemia induces the expression of cytokines in peripheral leucocytes and whether these inductions are suppressed by inhibiting postprandial hyperglycaemia with the alpha-glucosidase inhibitor miglitol. One group of streptozotocin-treated rats and age-matched saline-treated rats were orally administered sucrose only, and another group of streptozotocin-treated rats was administered sucrose with miglitol, at a single daily dose for 4 d, under 4 h fasting conditions. Blood glucose levels at 0, 0.25, 0.5, 1, 2 and 3 h and cytokine mRNA in peripheral leucocytes at 0 and 3 h after sucrose loading on days 1 and 4 from the start of sucrose loading were determined. Streptozotocin-treated rats showed moderate postprandial hyperglycaemia (>2000 mg/l) at 0.25-1 h after sucrose loading on days 1 and 4. Postprandial hyperglycaemia was not observed in the miglitol-treated rats loaded with sucrose. Gene expression levels of IL-1beta and TNF-alpha were higher in the streptozotocin-treated rats at fasting on day 1 than in saline-treated rats. Fasting IL-1beta and TNF-alpha gene expression on day 1 were not only increased at 3 h on the same day of sucrose loading, but was also increased at the fasting period on day 4. These inductions on day 4 by intermittent sucrose administration were inhibited by miglitol. The present results suggest that miglitol decreases postprandial hyperglycaemia and intermittent sucrose-induced expression of the IL-1beta and TNF-alpha genes in rat peripheral leucocytes.
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PMID:The alpha-glucosidase inhibitor miglitol suppresses postprandial hyperglycaemia and interleukin-1beta and tumour necrosis factor-alpha gene expression in rat peripheral leucocytes induced by intermittent sucrose loading. 1913 43


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