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)

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

In this study the influence of 14 antibiotics, 12 of them orally applicable, on human enterokinase was investigated. The effects of these substances on the activities of human disaccharidases were also examined. The enterokinase activity is more sensitive to the studied antibiotics than is human lactase, saccharase or isomaltase. Unphysiologically high concentrations of penicillins, cephalexin and chloramphenicol (10(-2) Mol/l) inhibited enterokinase, tetracycline (doxycycline) in a dose of 10(-3) m reduced the activity of this enzyme by 50%, neomycinsulphate and the sulphates of polymyxin B and E have no effect on the disaccharidases. On the contrary, these substances are the best inhibitors of enterokinase among the tested antibiotics. Neomycin or polymyxin (10(-4) Mol/l) causes a 50% inhibition of a physiological quantity of this enzyme. Therapeutic doses of both antibiotics may reduce the enterokinase activity by 70% to 90%, while the activity of trypsin is not affected unless a concentration greater than 10(-2) m is used. The inhibition is not only caused by the anion (SO4) of these antibiotics, since sulphates reduce the enterokinase only in concentrations higher than 10(-3) Mol/l in man. The mechanism of inhibition is not effected by binding cholic acids under test conditions. Both polymyxin and neomycin inhibit the enterokinase activity with and without glycodeoxycholic acid. Further studies showed that the type of inhibition is competitive in both cases. The inhibition constant K2 of neomycin-B-sulphate is 8.7X10(-5) Mol/l, of polymyxin-E-sulphate 8.6X10(-5) Mol/l. The inhibition type of penicillins, cephalosporins and doxycycline is noncompetitive, thus contrasting that of neomycin and polymyxin.
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PMID:[The influence of orally applicable antibiotics on the activities of human enterokinase and disaccharidases (author's transl)]. 98 20

The experiments on dogs have shown that during 3-5 weeks after resection of 1/3 and 2/3 of the pancreas the total amount of the excreted intestinal juice and the content of proper enteric enzymes in it (enterokinase, alkaline phosphatase and saccharase) are decreased. According to the author's data the activity of intestinal juice amylase and lipase being enzymes mostly of the pancreatic origin, transferred in the small intestine from blood, is enhanced due to impairment of the histo-hematic barrier in the region of the resected pancreatic stump. 2-3 months following resection of 2/3 of the pancreatic gland the amount of excreted intestinal juice was nearly unchanged, but the content of proper enteric enzymes was somewhat increased, as compared with background indices.
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PMID:[Secretory activity of the small intestine after resection of the pancreas]. 101 22

The interaction between malnutrition and exposure to a mucosal damaging agent, difluoromethylornithine (DFMO), was examined by monitoring the small-intestinal changes in weanling rats. Malnutrition as induced by the expanded-litter method resulted in severe reduction in body weights in the expanded litters as compared to normal litters. Subsequent treatment of malnourished and well-nourished pups with DFMO for 7 days resulted in decreases in small-intestinal weights and enzyme contents. A 2 factors (well-nourished and malnourished) by 2 factors (DFMO-treated and nontreated) analysis of variance showed no interaction between malnutrition and DFMO treatment in terms of food intake, total mucosal protein, and contents of enterokinase, leucine aminopeptidase and sucrase. Very slight and insignificant interactions (p less than or equal to 0.2) were found for body weights, intestinal weights and total DNA content. Only one parameter studied, the maltase content, showed significant interaction between malnutrition and DFMO treatment (p less than 0.05). Three weeks after the withdrawal of DFMO, essentially all the changes caused by DFMO recovered. But those changes caused by malnutrition did not, such that the malnourished group, whether treated with DFMO or not, still remained significantly less than the control group in their small-intestinal parameters. Analysis of variance showed no interaction between malnutrition and DFMO treatment in the recovery phase. The results suggest that malnutrition is a more important factor in determining the intestinal damage and that malnutrition in the immediate postnatal period does not increase the sensitivity of the small intestine to the damaging effect of DFMO.
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PMID:Interaction of malnutrition and difluoromethylornithine-induced intestinal mucosal damage: degree of severity and subsequent recovery. 285 68

The activities of enteropeptidase, alanine aminopeptidase, sucrase, and leucine aminopeptidase were determined in mucosa biopsies taken from three defined places of the duodenum and in duodenal juice. We examined 23 adults with a histological proven normal mucosa and 10 patients suffering from duodenitis grade I. Using multivariate evaluation of all the four enzyme activities of the three mucosa sites, we could differentiate duodenitis from normal mucosa with an efficiency of 88%.
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PMID:[Biochemical diagnosis of duodenitis]. 287 20

Oral feeding of DL-difluoromethyl ornithine (DFMO) (2% in water ad libitum) for 14 days has no detectable effect on the small intestine of adult rats. Similar feeding of DFMO to weanling rat pups caused diarrhea in three to four days accompanied by a decrease in food consumption and body weight compared to age-matched controls. Significant decreases in small intestinal mucosal weight, total protein, DNA, enterokinase, leucine amino peptidase, sucrase, and maltase contents were observed in the DFMO-treated group four days after treatment. Extending the treatment to seven days led to a more severe reduction in these parameters. Villous atrophy of the mucosa was demonstrable by light microscopy and morphometric measurements. The mucosa of the DFMO-treated rat pups showed a reduction in total thickness and villous height but no change in crypt depth. A significant reduction in villus-crypt ratio was also seen. Changes in small intestinal mucosal parameters were not due to a decrease in food intake since pair-fed, age-matched rat pups showed no biochemical changes compared to control pups. DFMO-treated weanling rats showed less than 5% of ornithine decarboxylase (ODC) activity when compared to age-matched control animals. The effects observed on the small intestinal mucosa are presumably due to inhibition of ornithine decarboxylase activities by DFMO which prevents the proliferation, regeneration, and maturation of epithelial cells. The relative insensitivity of the adult rat small intestine to DFMO treatment suggests a lesser dependence of its intestinal mucosa to ODC activities.
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PMID:Effect of difluoromethyl ornithine (DFMO) on small intestine of adult and weanling rats. 311 4

In a study of changes in digestive enzymes after massive intestinal resection and the mechanisms by which such changes occur, rats were sacrified 4 wk after removal of the proximal two-thirds of the small intestine. Alterations in the mucosal levels of sucrase, enterokinase, and dipeptide hydrolase (L-leucyl-L-alanine substrate) were examined in the light of associated changes in protein. DNA and wet mucosal weight, measured in standardized gut segments from various regions of intestine. Metabolic studies showed that normal growth patterns were reestablished after the operation but significant elevations in stool weight and fecal nitrogen occurred in the second postoperative week, falling towards normal by the 4th wk. In standard gut segments wet weight of mucosa, protein, and DNA rose, especially in distal segments, DNA increasing disproportionately. Mucosal levels of the proximally distributed and membrane-bound enzymes, sucrase and enterokinase, showed similar patterns of change: when enzyme activity was expressed in terms of the total per segment, proximally there were considerable increases in both enzymes, but, expressed in terms of specific activity, that of sucrase fell and that of enterokinase was unaltered. By contrast, the largely soluble and more distally distributed dipeptide hydrolase increased more in distal segments and the increases in total activity were accompanied by lesser increases in specific activity. However, in spite of increases in total activity, enzyme activity per milligram DNA fell by over 50% in postanastomotic segments. Subcellular distribution studies showed no change in the percentage of the total activity which was membrane-bound and zymograms confirmed that no new dipeptide hydrolase had appeared after resection. It is concluded that increases in the segmental totals of various enzymes seen after resection are achieved by disproportinate increases in the number of mucosal cells per segment and that the greatest change in a particular enzyme occurs in the region where the enzyme is normally found in highest concentration.
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PMID:Changes in sucrase, enterokinase, and peptide hydrolase after intestinal resection. The association of cellular hyperplasia and adaptation. 469 57

Three enzymes of intestinal origin-enterokinase, alkaline phosphatase, and sucrase-were released into the perfused small intestinal lumen of the rat upon intravenous injection of the gastrointestinal hormone cholecystokinin-pancreozymin (CCK-PZ). The presence of bile in the perfusion fluid greatly augmented this release. The results suggest that a combined mechanism of enzyme liberation due to direct hormonal stimulation of the gut wall and further solubilization of released intestinal enzymes by bile may be responsible for the appearance of these enzymes in the gut lumen.
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PMID:Hormone-elicited enzyme release by the small intestinal wall. 504 Aug 34

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 report the characterization of N-linked oligosaccharides on six foreign glycoproteins secreted from the methylotrophic yeast Pichia pastoris. These proteins included: a bacterial enzyme, Bacillus licheniformis alpha-amylase; three fungal enzymes, Saccharomyces cerevisiae invertase, Penicillium minioluteum dextranase, and Mucor pusillus aspartic protease; and two higher eukaryotic proteins, Boophilus microplus (tick) gut antigen and bovine enterokinase catalytic subunit. The carbohydrates on these proteins were observed to vary in size, with Man8GlcNAc2 and Man9GlcNAc2 structures being the most frequently observed species. Substantial amounts of shorter oligomannoside structures were present only on invertase, and longer structures (up to Man18GlcNAc2) were common on aspartic protease and enterokinase. Phosphorylated oligosaccharides were observed on one protein, aspartic protease. Unlike oligosaccharides on glycoproteins secreted from S. cerevisiae, no terminal alpha1,3-linked mannosylation was observed on any of the six P. pastoris-secreted proteins. Changing the growth and induction medium from a minimal salt-based medium to a molasses-based medium had little effect on the size of the oligomannosides. From these results, it is apparent that most foreign proteins secreted from P. pastoris are not subjected to the extensive mannosylation (hyperglycosylation) that commonly occurs in proteins secreted from S. cerevisiae.
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PMID:Variation in N-linked oligosaccharide structures on heterologous proteins secreted by the methylotrophic yeast Pichia pastoris. 979 Aug 82


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