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 effect of diets containing various amounts of casein and starch on enzymes bound to the brush border of the small intestine and kidney of rats were investigated with the following results. 1) Diets with low starch and high casein contents resulted in higher specific activity of leucineaminopeptidase in the small intestine than diets with high starch and low casein contents. Diets with high starch and low casein contents increased the specific activity of maltase. 2) Rat small intestine contains at least two isoenzymes of leucineaminopeptidase: one bound to the brush border and the other not bound to it but recoverable in the soluble fraction. Only the former was influenced by the diet. 3) The maximum velocity (Vmax) of leucineaminopeptidase bound to the brush border was twice as much in rats on a high casein diet as in those on a low casein diet, but the Michaelis constant (Km) was approximately the same in both groups of rats. 4) Leucineaminopeptidase and maltase activities in the kidney were not influenced by diet.
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PMID:Effect of diet on enzymes of the brush border of the small intestine and kidney of rats. 120 41

In three experimental groups of white rats receiving cacein in the morning, at noon and at night, over a period of one month, glucose resorption was studied in the hours of casein alimentation. The method of accumulating preparation from the mucosa "in vitro" was employed, and parallel to glucose resorption, maltase activity was also investigated. The results obtained are discussed in the light of modern concepts on membranous digestion and active transport, and more particularly, on interactions of the monomers at membrane level. Interpretation is made of the marked resorption of glucose, observed in the experimental group receiving casein at noon, and the possibility of practical application of the results recovered in rational dietetic nutrition is discussed.
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PMID:[Study of glucose resorption during rhythmic protein feeding in a chronic experiment on white rats]. 123 3

Previously we have shown that rats fed a diet containing raw peanut meal as the sole source of protein exhibited alterations in enzyme activity and composition of certain organs. To determine the effects of isolated peanut lectin on body growth and on the intestines, experiments were carried out in weanling, male, Sprague-Dawley rats fed a casein diet incorporated with purified peanut lectin at three levels, 0.004, 0.04, and 0.2% for 23 days. Body weight gain was normal with all three diets. In rats fed the 0.004 and 0.04% peanut lectin, there were no changes in any of the small intestinal mucosal parameters under study. However, in rats consuming the 0.2% peanut lectin diet, the proximal, mid, and distal third regions of the small intestines all showed marked increases in mucosal weight, protein, and DNA contents, but without altered villus morphology. Of the 3 brush border enzymes studied, namely maltase, gamma-glutamyltranspeptidase, and alkaline phosphatase, none was altered in activity in any region, suggesting that microvillus integrity was normal. These results are similar to the reported actions of red kidney bean lectin on the intestines. We conclude that peanut lectin at up to 0.2% of the diet does not inhibit food intake or growth of weanling rats and is apparently trophic for all areas of the small intestines.
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PMID:Tolerance to long-term feeding of isolated peanut lectin in the rat: evidence for a trophic effect on the small intestines. 198 49

We examined the age-related changes of renal brush border enzymes of male Donryu rats under different dietary conditions. High protein diet (51% casein) markedly decreased the activity of renal leucine aminopeptidase as compared with low protein diet (8% casein). No significant difference, however, was observed in the activity of renal maltase between high and low protein diets. Alkaline phosphatase activity from young adult (3-month-old) rats in the high protein diet group was significantly lower than that in the low protein diet groups. From these results, it is inferred that dietary conditions affect the age-related alteration of renal brush border enzymes. Together with the previous results, it is suggested that proteins of renal brush borders are altered differently during the aging process.
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PMID:Age-related changes in brush border enzymes under different dietary conditions. 265 43

Alkaline treatment of proteins leads to chemical changes which alter the proteins' digestibility. Severely alkali-treated casein (0.2N NaOH, 80 degrees C, 1 hour) in the diet reduces food intake and growth of young but not of adult Sprague Dawley rats. Gastrointestinal transit time is not reduced significantly in either young or adult rats. Food intake and growth rate are improved by amino acid supplementation. In this case, protein content and total leucine aminopeptidase activity are increased in the distal part of the small intestine whereas gamma-glutamyl-transpeptidase and maltase activities are increased in both the proximal and distal parts. Alkaline phosphatase activity remains unchanged. These intestinal adaptations differ from those observed in rats receiving a diet containing untreated casein and graded levels of a synthetic trypsin inhibitor. In the latter, protein digestibility remains high, gamma-glutamyltranspeptidase and also maltase activities are increased in the proximal and medial parts of the small intestine only. Intestinal adaptation in rats receiving alkali-treated casein does not result from a deficiency of pancreatic proteases activity. Ileal accumulation of undigested peptides from insufficient hydrolysis of alkali-treated casein may account for these mucosal adaptations.
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PMID:Effect of severely alkali-treated casein on gastrointestinal transit and selected intestinal enzyme activities. 287 20

Some diets exert a considerable influence on porphyrin metabolism and induction of microsomal liver enzymes in experimental porphyria induced by hexachlorobenzene (HCB). As HCB and its metabolites come into direct contact with intestinal mucosa, this study investigated the changes in the activities of intestinal disaccharidases and gamma-glutamyl transferase in a model of HCB-induced porphyria. The effects of different diets on enzymatic activities during HCB intoxication were also studied. HCB was administered by gastric tube at 3.5 mmol/kg body weight daily for 90 and 61 days. HCB intoxication strongly diminished the activities of intestinal lactase, maltase, sucrase, cellobiase and trechalase. Carbohydrate diets (with 78 weight % glucose or starch), given simultaneously with HCB treatment, exerted a protective effect on disaccharidase activities. These regimens maintained cellobiase and trechalase within the normal levels and even increased maltase. High-fat/high-protein diets (with 30% either butter or sunflower oil and 31% casein) aggravated the decrease of all disaccharidases. In contrast with the decrease in disaccharidase activity, intestinal gamma-glutamyl transferase was increased, suggesting multiple mechanisms for the action of HCB intoxication on the intestinal enzyme system. Diet had a pronounced modifying effect.
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PMID:Changes in some intestinal enzyme activities in experimental hexachlorobenzene-induced porphyria and modifying effects of diet. 288 67

The effect of methionine dietary deficiency on food intake, weight gain, liver and kidney weight, feed conversion rate, protein efficiency ratio, maltase and leucineaminopeptidase (LAPase) activities of the intestinal mucosa as well as renal LAPase activity was studied. Three groups of female Wistar rats, weighing between 40-60 g, were fed for 25 days on either Diet A (casein supplemented with 0.6% DL-methionine), Diet B (amino acid mixture simulating casein also supplemented with 0.6% methionine) or Diet C (amino acid mixture with 0.67% methionine deficiency with respect to Diet A). The results show no significant differences in either growth or enzymatic activity between the rats fed on Diet A and those on Diet B. The animals fed on Diet C show an increase in intestinal (P less than 0.01, vs Diet B) and renal (P less than 0.005, vs Diet A) LAPase activity, although intestinal maltase activity remained unchanged. Food intake, weight gain, organ weight and nutritional parameters obtained in rats fed on Diet C showed no statistically significant changes, with the exception of kidney weight which decreased (P less than 0.005) when compared to those fed on Diet B.
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PMID:Changes in enzymatic activity of small intestine and kidney of rats by a methionine deficient diet. 307 19

The effect of protein malnutrition on the function, fluidity and composition of the intestinal microvillus membrane was studied in growing rats. Weanling male rats were fed diets containing 10% protein derived from either wheat gluten (experimental diet) or casein (control diet). Intestinal microvillus membranes were isolated after a 7-wk feeding period. The functionality of the membranes, as assessed by the level of activity of the four enzymes alkaline phosphatase, gamma-glutamyl transpeptidase, leucine aminopeptidase and maltase, showed no difference between the membranes derived from the experimental and the control animals. Similar Arrhenius plot patterns of alkaline phosphatase activity (13-50 degrees C) and of the fluorescence anisotropy parameter (8-40 degrees C) were observed for both types of membranes with respect to the transition temperatures and energies of activation. In addition, the similarity between the membranes derived from the experimental and the control animals was also manifested in the cholesterol and phospholipid content. The study demonstrates that despite the extreme nutritional stress exerted on the gluten-fed rats, the integrity and functionality of the intestinal microvillus membrane was adequately maintained.
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PMID:Protein malnutrition and the function and fluidity of the intestinal microvillus membrane in growing rats. 310 69

The effect of high-protein fish meal on maltase and leucine aminopeptidase (LAPase) activities of the intestinal mucosa as well as the renal LAPase activity was studied. Four groups of female Wistar rats, weighing between 40-60 g, were fed diets with a 4 or 12% protein content of dry matter for 25 days. The protein source was casein for the control groups and fish meal derived from Coryphaenoides rupestris for the test groups. The results show a decrease (p less than 0.005) in intestinal maltase and LAPase activities and renal LAPase activity in animals fed with 12% of fish meal protein compared to those fed with casein, while the rats fed 4% of fish meal protein showed a decrease in intestinal maltase activity and no significant difference in LAPase activity compared with the control group. These results seem to indicate that the intestinal maltase is influenced by the quality and quantity of dietary protein, while the intestinal and renal LAPase activity is only changed by the quality of protein.
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PMID:Effects of fish meal as source of protein on intestinal maltase activity and intestinal and renal leucine aminopeptidase activity of growing rats. 353 98

The effects of variation in dietary protein content on small intestinal brush border and cytosol peptide hydrolase activities have been investigated. One group of rats was fed a high protein diet (55% casein) and another group was fed a low protein diet (10% casein). After 1 wk, brush border peptide hydrolase activity (L-leucyl-beta-naphthylamide as substrate) and cytosol peptide hydrolase activity (L-prolyl-L-leucine as substrate) were determined in mucosae taken from the proximal, middle, and distal small intestine. As judged by several parameters, brush border peptide hydrolase activity was significantly greater in rats fed the high protein diet when data for corresponding segments were compared. In contrast, no significant difference was seen in cytosol peptide hydrolase activity. IN A SECOND STUDY, BRUSH BORDER AND CYTOSOL PEPTIDE HYDROLASE ACTIVITIES WERE DETERMINED IN THE PROXIMAL INTESTINE BY UTILIZING AN ADDITIONAL THREE PEPTIDE SUBSTRATES: L-leucyl-L-alanine, L-phenylalanylglycine, and glycyl-L-phenylalanine. Sucrase, maltase, and alkaline phosphatase activities were also determined. As before, brush border peptide hydrolase activities were significantly greater in rats fed the high protein diet. However, activities of the nonproteolytic brush border enzymes did not vary significantly with diet. In contrast to the results obtained with L-prolyl-L-leucine as substrate for the cytosol enzymes, cytosol activity against the three additional peptide substrates was greater in rats fed the high protein diet. It is suggested that the brush border peptide hydrolase response to variation in dietary protein content represents a functional adaptation analogous to the regulation of intestinal disaccharidases by dietary carbohydrates. The implication of the differential responses of the cytosol peptide hydrolases is uncertain, since little is known of the functional role of these nonorgan-specific enzymes.
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PMID:The responses of rat intestinal brush border and cytosol peptide hydrolase activities to variation in dietary protein content: dietary regulation of intestinal peptide hydrolases. 443 Jul 19


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