Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dog enterocyte brush border proteins have been studied after a 75% proximal resection of the small bowel. This study was carried on microvillar membrane preparations purified from ileal mucosa sampled before and after regeneration on neighbouring intestinal segments, each animal acting as its own control. After six weeks of regeneration a statistically significant decrease of the following enzyme specific activities was observed: lactase, cellobiase, maltase, sucrase, palatinase, dextranase, trehalase, alkaline phosphatase, aminopeptidase and gamma-glutamyl transferase. Analysis of brush border proteins by polyacrylamide gel electrophoresis in presence of sodium dodecyl sulphate have shown after regeneration a decreased rate for the proteins with a molecular weight higher than 100,000 daltons. Modifications of electrophoretic patterns seem to be related to the specific activity decreases observed for brush border enzymes after regeneration, since the molecular weight of these enzymes were found between 116,000 and 285,000 daltons, after gel filtration.
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PMID:Effect of massive proximal small bowel resection on intestinal brush border membrane proteins in the dog. 8 27

Leucine beta-naphthylamidase associated with the microvilli membranes of rabbit small intestine was solubilized with papain [EC 3.4.22.2] and purified by Sephadex G-200 gel filtration, DEAE-cellulose column chromatography, passage through a column of Sepharose 4B coupled with anti-sucrase antibodies and preparative disc electrophoresis in polyacrylamide gel. The purified enzyme was homogeneous on ultracentrifugation and disc electrophoresis, but a double immunodiffusion test showed the presence of a minor component which was probably denatured enzyme. The molecular weight of the purified enzyme was estimated to be 225,000 by Sephadex G-200 gel filtration and the sedimentation coefficient (S-0-20, w) was found to be 6.90S. Purified enzyme required bovine serum albumin for maximal activity, perhaps for its protection from autodigestion. It hydrolyzed, in addition to L-leucine beta-naphthylamide, various L-amino acid beta-naphthylamides and dipeptides with a free alpha-amino group, but did not hydrolyze benzoyl-L-arginine beta-naphthylamide. Therefore, the purified enzyme is an aminopeptidase. Hg-2+ and Cu-2+ ions strongly inhibited the enzyme activity, but other metal ions and EDTA showed no or only slight effect. N-Ethylmaleimide exhibited a weak inhibition. Purified enzyme had an optimal pH and Km value for leucine beta-naphthylamide similar to those of enzymes from other sources. Antibodies against the purified enzyme were raised in guinea pigs. The antibodies obtained were found by double immunodiffusion to be specific for the enzyme. They precipitated the enzyme quantitatively and partially inhibited the enzyme activity.
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PMID:Purification and properties of leucine beta-naphthylamidase from rabbit small-intestinal mucosal cells. 23 93

The effects of corticosteroid have been studied in rats submitted to oral administration of prednisone (5 mg. per kg. per day) during 8, 15, 30, and 90 days. The results were compared to those obtained after parenteral administration of hydrocortisone acetate (50 mg. per kg. per day intramuscularly). The morphometric changes of the villus-crypt axis and the brush border enzymic content of the mucosa (sucrase, enterokinase, alkaline phosphatase, and aminopeptidase) were the parameters investigated at the duodenal, jejunal, and ileal levels. Oral administration of prednisone resulted in a significant increase of the duodenal villous height at the 15th (+ 13 per cent, p less than 0.01), 30th (+ 33 per cent, p less than 0.001), and 90th day (+ 56 per cent, p less than 0.001), whereas in the jejunum a constant decrease of the villous height was noted. Parenteral hydrocortisone administration did not affect intestinal morphology. Effects of oral corticosteroids on the microvillous enzymic activities were related to both intestinal level and duration of corticoids administration: (1) in the duodenum increase of sucrase, alkaline phosphatase, and aminopeptidase during 30 days followed by normalization at the 90th day, (2) an initial increase of sucrase, alkaline phosphatase, and aminopeptidase limited to the first 8 days in the jejunum, and (3) a significant rise of alkaline phosphatase (greater than 100 per cent, p less than 0.001) and enterokinase (greater than 100 per cent, p less than 0.001) in the ileum at the 15th day of treatment. Parenteral corticosteroid administration was associated with a significant increase of both sucrase and enterokinase activities. The present study suggests that: (1) Corticosteroids exert a direct effect on the intestinal morphology varying with the intestinal level and duration of treatment. (2) No correlation could be established between anatomic and functional changes. (3) Oral corticosteroids exert an enhancing effect of the brush border enzymic activities, even in the adult mucosa and particularly at the ileal level where they stimulate significantly the enterokinase mucosal activity. (4) Parenteral corticosteroids exert a more specific effect limited to sucrase and enterokinase enhancement.
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PMID:Effects of oral and parenteral corticosteroids on intestinal villous morphology and brush border enzymes in the rat. 31 75

A modification of Weiser's (1973) cell isolation method was used in order to study the developmental pattern of various intestinal enzyme activities in villus and crypt cells of normal rats from 5 days after birth until 8 weeks. Alkaline phosphatase and enterokinase activities were always located in the upper villus zone during postnatal development. Enterokinase activity was higher in the upper villus cells during the third week of life than after this period. Aminopeptidase activity was located in the crypt cells during the first week, its maximum activity remained in this area until the third week. At this time, sucrase activity appeared in the crypt cells, then aminopeptidase and sucrase activities rose to the villus zone during the fourth week. Amylase activity was detected along the entire crypt-villus axis 5 days after birth, reaching maximum activity in crypt cells at the end of the first week and in the upper villus cells after the fourth week. In contrast with the other enzymes studied almost all amylase activity was soluble in the youngest animals whereas at weaning most of the activity appeared in a particulate form in the villus cells. But in the crypt cells the ratio between particulate and soluble form remained unchanged until the adult stage. Various hypotheses are advanced to explain the patterns of evolution of the different enzymes.
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PMID:Intestinal enzymes activities in isolated villus and crypt cells during postnatal development of the rat. 83 93

Rat small bowel was perfused in vivo and ex vivo in the absence of biliary and pancreatic secretion. Intraluminal release of sucrase, alkaline phosphatase, aminopeptidase and enterokinase was significantly increased after administration of PG E1 and E2 1 and 5 microgram/kg. This suggests a direct stimulation of the intestinal mucosa, which might be mediated through cyclic AMP; dibutyryl cAMP significantly stimulates intraluminal release of proteins, sucrase and enterokinase.
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PMID:Prostaglandins E1 and E2 stimulate release of intestinal brush border enzymes. 90 72

The chronic diarrhea observed in young malnourished infants that is sensitive to dietary glucose and other carbohydrates is associated with variable degrees of patchy mucosal villous atrophy. To explore intrinsic mucosal function in the pathogenesis of this alimentary intolerance, we have conducted an immunohistologic investigation of brush-border enzyme proteins of clinically obtained, mucosal biopsy samples. We used a group of monoclonal antibodies against human brush-border aminopeptidase, sucrase/isomaltase (SI), maltase, and lactase enzyme proteins. SI was strongly and uniformly expressed in crypts and villi of 11 of the 14 subjects; in 3 subjects, however, SI was expressed in a mosaic pattern. Maltase and lactase were occasionally absent, but more commonly were expressed in a mosaic distribution. The mosaic expression of brush-border enzyme proteins has been reported in congenital enzyme deficiencies associated with normal intestinal histology. We report the mosaic expression of brush-border enzyme proteins as a functional alteration associated with a pathological lesion of the mucosa in infants with chronic diarrhea. Our observation challenges the existing concept of ontogenic regulation of brush-border enzyme activity.
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PMID:Mosaic expression of brush-border enzymes in infants with chronic diarrhea and malnutrition. 135 33

This study compares the effects of amino acid addition to an elemental liquid diet containing carbohydrates and triglycerides given either intragastrically or intravenously on the morphology and on hydrolase activities in the jejunum and ileum of adult rats. The isocaloric mixtures were administered for 4 days and control rats received an isocaloric laboratory diet orally. Independent of their content in amino acid, all mixtures given intravenously caused a drop in mucosal weight and a shortening of the height of the villi in both the jejunum and ileum. By enteral route, the addition of amino acids to a carbohydrate-triglyceride liquid diet led to the maintenance of normal villus height (this effect being prominent in the ileum) and to a significant increase of jejunal sucrase and aminopeptidase activities when compared with the carbohydrate-triglyceride mixture. Feeding the mixtures by parenteral route caused a significant drop of both enzyme activities. In contrast, lactase activity was generally not modified by the route of nutrient administration or by the composition of the diets. However, the absence of amino acid in the mixture given intravenously caused a specific drop of lactase activity in the ileum. Ileal sucrase activity was lowered dramatically by intragastric or intravenous feeding of the elemental diets. This effect was not modulated by the presence of amino acids. The presence of amino acids caused a significant drop of aminopeptidase activity in the ileum independently of the route of administration when compared with animals receiving the carbohydrate-triglyceride liquid diet.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of amino acids in mixtures given by enteral or parenteral route on intestinal morphology and hydrolases in rats. 150 57

The effects of long-term starvation on the activities of sucrase, lactase, and aminopeptidase, and on their respective mRNA were determined in the small intestine of thyroidectomized and sham-operated adult rats. Thyroidectomy reduced the protein loss at the level of the intestinal brush border membranes during starvation. Prolonged fasting caused a significant decrease in sucrase activity, but thyroidectomy partly prevented this effect. However, the amount of the corresponding mRNA dropped during long term starvation without incidence of thyroidectomy. Lactase activity in the brush border membranes was increased by starvation, and thyroidectomy caused a further elevation of the enzyme activity. Simultaneously, lactase mRNA content rose only slightly compared to the enzyme activity. Aminopeptidase activity and mRNA content decreased during starvation and thyroidectomy did not prevent this process. These results indicate that intestinal hydrolases respond non-coordinately to long-term food deprivation. In addition, the thyroid status of the animals has a direct influence on the adaptation of several brush border hydrolases to starvation. This suggests that the drop in plasma thyroid hormones during fasting allows a better maintenance of protein content and of hydrolase activities in the brush border membranes of the small intestine. These adaptive processes seemed to be partly controlled at a post-transcriptional level.
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PMID:Adaptation of intestinal hydrolases to starvation in rats: effect of thyroid function. 193 43

Adaptive responses of brush border hydrolases and crypt cell proliferation were measured in the jejunum and ileum of 4-mo-old adult and 28-mo-old senescent male Wistar rats. Responses were measured after rats were deprived of food and then refed with a normoprotein diet (17% protein) or an isoenergetic high protein diet (70% protein). The young rats deprived of food then refed for 18 h with the high protein diet showed better body weight recovery than did old animals. Withholding food for 48 h induced a more pronounced drop of sucrase activity in the intestine of the old rats relative to young rats. Refeeding the high protein diet caused a better recovery of sucrase activity in the jejunum of young rats relative to senescent rats. In the aged animals, sucrase activity in the jejunum remained significantly lower after refeeding both diets. Compared with nourished controls, aged rats showed enzyme activity to be completely restored in the ileum. The high protein diet increased aminopeptidase activity in the jejunum and ileum of young rats, in contrast to the senescent rats in which the increase of enzyme activity was restricted to the ileum. In the jejunum of aged rats, the cell migration rate from crypt base to villus tip was reduced after refeeding, but no age-related changes were observed in the ileum. Our results indicate that the jejunum of senescent rats exhibits reduced adaptive capacities that may be partly compensated by enhanced ileal functions.
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PMID:Ileal compensation for age-dependent loss of jejunal function in rats. 200 2

The regulatory effect of epidermal growth factor (EGF) on the developmental pattern of brush border hydrolases was studied in the proximal jejunum and colon of the newborn rat. In the proximal colon, daily administration of EGF for 1, 3, or 5 days postpartum inhibited the postnatal increase in lactase, maltase, and aminopeptidase specific activities. In contrast, in the jejunum EGF did not influence lactase activity, inconsistently increased maltase activity, and partly prevented the early postnatal decrease in aminopeptidase activity. In the proximal colon, EGF showed additive effects with T4 and hydrocortisone on the inhibition of lactase activity. In the jejunum, EGF potentiated the effect of hydrocortisone and T4 on the expression of sucrase activity and had only a slight effect when injected alone. The incorporation rate of [3H]thymidine in the proximal colon and jejunum was not different in control and treated rats, indicating the absence of an effect of EGF on DNA synthesis. These results show that EGF may play an important physiological role in the enzymatic differentiation of the developing intestine during early postnatal development. Alone or acting with T4 or glucocorticoids, EGF may induce the decline of digestive hydrolases in the proximal colon. In the small intestine EGF may play a major role in the triggering of sucrase expression.
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PMID:Effect of epidermal growth factor on the expression of digestive hydrolases in the jejunum and colon of newborn rats. 211 92


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