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)

The effect of vitamin C deficiency on various enzymes of the intestinal epithelium has been studied in guinea pigs. Brush border sucrase and alkaline phosphatase activities were considerably enhanced (p less than 0.001), but leucine aminopeptidase levels were reduced in scorbutic animals compared to the control group. There was essentially no change in the activity of maltase under these conditions. Kinetic studies with sucrase and alkaline phosphatase in control and scorbutic animals revealed that augmentation of the enzyme activities in scurvy is due to enhanced enzyme contents. Lactate dehydrogenase, succinate dehydrogenase, glucose-6-phosphatase and Mg+2 ATPase also exhibited reduced activities in the intestine of vitamin-C-deficient animals. Observed alterations in the activities of intestinal enzymes in scurvy were restored to control levels upon feeding of vitamin C to scorbutic guinea pigs.
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PMID:Alterations in the activities of intestinal enzymes in vitamin-C-deficient guinea pigs. 627 90

The present study was undertaken to determine if three sources of dietary fiber would alter length, weight, DNA, protein or enzyme activity in the small intestine since various fibers are known to decrease intestinal absorption. Rats were fed semipurified diets that contained either 20% cellulose (C), 20% oat bran, 5% pectin (P) or no fiber source (FF). Leucine aminopeptidase activity were significantly greater in the P and C groups when compared with the FF group. There were no significant differences in sucrase activity. Animals in the P group had heavier and longer small intestine and heavier mucosa than the FF group. There were no significant differences in total mucosal DNA or protein. These results indicate that two sources of dietary fiber, cellulose and pectin, can change leucine aminopeptidase activity in the small intestine.
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PMID:Effects of dietary cellulose, pectin and oat bran on the small intestine in the rat. 628 91

Intestinal brush borders were isolated from vitamin D-3-treated and vitamin D-deficient chicks, and protein topography in the paired preparations assessed by the enzymatic release of four marker hydrolases. Exposure of the brush borders to the protease bromelain resulted in soluble levels of alkaline phosphatase, leucine aminopeptidase, maltase, and sucrase activities from preparations of vitamin D-3-treated birds that were 42%, 75%, 64%, and 56%, respectively, of corresponding activities released in preparations from rachitic chicks. Analyses for recovery of enzyme activity revealed that bromelain treatment selectively inactivated 43% of the alkaline phosphatase activity of brush borders obtained from vitamin D-3-replete birds, and preferentially diminished recovered sucrase activity in preparations from vitamin D-deficient chicks. In additional experiments, brush borders isolated from rachitic birds were treated in vitro with the polyene antibiotic filipin or an equivalent volume of vehicle. Subsequent exposure of such preparations to bromelain resulted in little or no differences in levels of marker hydrolase specific activities released from filipin- or vehicle-treated brush borders. However, analyses of membrane-bound specific activities after treatment of brush border preparations with a range of filipin concentrations, revealed a biphasic inhibition of approx. 30% for both maltase and sucrase, relative to vehicle controls, and a smaller effect on alkaline phosphatase and leucine aminopeptidase.
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PMID:Intestinal brush border hydrolase topography. Effects of vitamin D-3 and filipin. 629 47

Cells of Streptococcus mitis ATCC 903 were converted to stable protoplasts by the cell wall-degrading M-1 enzyme of the mutanolysin complex isolated from Streptomyces globisporus. Over 90% of total glucokinase (EC 2.7.1.2), aminopeptidase (EC 3.4.11.1), and dextranglucosidase (EC 3.2.1.70) was recovered in the cytoplasmic fraction, whereas over 20% of total invertase (beta-fructofuranosidase: EC 3.2.1.26) was released during protoplast formation. ATPase (EC 3.6.1.3). chymotrypsin-like protease (EC 3.4.21.1), arginine aminopeptidase (EC 3.4.11.6), and lactate dehydrogenase (EC 1.1.1.27) were detected in Triton X-100 extracts of the cytoplasmic membrane fraction by crossed immunoelectrophoresis in combination with enzyme-staining procedures. By these methods, NADH dehydrogenase (EC 1.6.99.3), aminopeptidase, and lactate dehydrogenase were detected in the cytoplasmic fraction. Aminopeptidases in the cytoplasmic fraction differed from this activity in the membrane fractions in electrophoretic mobility and substrate specificity.
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PMID:Protoplast formation and localization of enzymes in Streptococcus mitis. 634 41

Small intestinal development was followed in rats from 17 to 28 days of age in order to evaluate the interactions of diets, genetic preprogramming, and hormones in influencing developmental changes. Control pups, weaned naturally at 21-24 days, showed a gradual increase in body weight, intestinal length, and segmental mucosal weight, total DNA, and protein content. In contrast, pups weaned at 17 days showed an immediate increase in intestinal length, decrease in lactase, and precocious increase in sucrase and maltase. The changes in segmental mucosal weight, DNA and protein contents, however, paralleled that of controls. Pups nursed up to 25 days had a smaller body weight, shorter intestine, lighter mucosa, and lesser mucosal protein content. They showed no significant delay in the increase in sucrase and maltase together with a persistent higher level of lactase. Enterokinase and leucine aminopeptidase showed little change irrespective of the dietary modifications. Significant increases in segmental mucosal mass, DNA, and protein contents during the studied period were seen in all animals. At 19 days, early weaned pups had serum levels of corticosteroids about 3 times that of control or prolonged nursed pups. The results support the concept of an inherent biologic program as a basic control of intestinal ontogeny whereas dietary changes seem to have a modifying role and act directly, or in concert with, hormonal changes.
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PMID:Early weanling and precocious development of small intestine in rats: genetic, dietary or hormonal control. 635 Oct 6

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

The effect of dietary thiamin deficiency has been studied on intestinal functions and chemical composition of brush border membranes in rats. Intestinal uptake of glucose, glycine, alanine, and leucine was significantly stimulated in thiamin deficiency compared to pair-fed control group. Studies with glucose and glycine revealed that stimulation of the absorption process occurs only in the presence of Na+ but not in its absence. Km measured in the presence of 140 mM Na+ for glucose and glycine uptakes was reduced by 56 and 41%, respectively, but Vmax remained unaltered in vitamin deficiency. There was no change in these parameters in Na+-free medium (Km = 31.3 and 23.3 mM; Vmax = 17.2 to 19.7 and 13.5 to 16.4 mumol/10 min/g wet tissue, respectively) under these conditions. The activities of brush border sucrase, lactase, maltase, alkaline phosphatase, and leucine aminopeptidase were reduced by 42 to 66% in thiamin deficiency, compared to pair-fed controls. Kinetic studies with sucrase and alkaline phosphatase evinced that a decrease in Vmax (61 and 64%, respectively) with no change in Km (33.8 and 4.3 mM, respectively) was responsible for observed impairment in the enzyme activities in thiamin deficiency. Microvillus membrane proteins expressed on dry membrane basis were reduced by 20% in thiamin-deficient intestine. There was no difference in membrane sialic acid, cholesterol, phospholipids, and triglycerides fractions under these conditions. It is suggested that thinning of the microvillus membrane may be implicated in observed aberrations of intestinal functions in thiamin-deprived animals.
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PMID:Effect of dietary thiamin deficiency on intestinal functions in rats. 646 54

Intestinal metaplasia is defined as the appearance of intestinal epithelium in the stomach. Intestinal metaplasia is frequently found in populations with a high incidence of gastric cancer. Macroscopic demonstration of sucrase and trehalase with Tes-tape in many resected stomachs yielded new information for understanding the nature of intestinal metaplasia. Intestinal metaplasia can be classified into two types, complete and incomplete. The former is associated with the presence of sucrase, trehalase, leucine aminopeptidase, alkaline phosphatase, goblet cells and Paneth cells, and the latter with that of sucrase, leucine aminopeptidase and goblet cells, but not trehalase or Paneth cells. Goblet cells in the complete type of intestinal metaplasia contain sialomucin, as does the small intestine, while those in the incomplete type contain sulphomucin and sialomucin, as does the large intestine. Well-differentiated adenocarcinoma is closely related to intestinal metaplasia, especially the incomplete type. Atypical epithelium of intestinal metaplasia has been proposed as a more proximate stage of gastric cancer. Intestinal metaplasia can be diagnosed by staining with dye under endoscopic observation. A reduced level of pepsinogen I in the blood reflects the presence of severe intestinal metaplasia, which is understood to be a sign of high risk of gastric cancer. Intestinal metaplasia is supposed to be produced by components of food. Mutagens/carcinogens such as N-methyl-N'-nitro-soguanidine and N-propyl-N'-nitro-N-nitrosoguanidine can produce intestinal metaplasia in the glandular stomach of rats and gastric cancers. The formation of intestinal metaplasia precedes the appearance of adenocarcinoma in the glandular stomach. Intestinal metaplasia, which is a kind of host reaction to environmental agents, may result either from genetic change - change in DNA structure - or from epigenetic change - change in the differentiation mechanism. Preventive measures could be developed to suppress the development of intestinal metaplasia and to suppress the process of conversion of metaplastic cells to cancer cells.
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PMID:Intestinal metaplasia of the stomach as a precancerous stage. 675 88

Rat jejunum was perfused in vivo with sodium deoxycholate concentrations ranging from 0.125 to 4 mM. The release of total protein and some brush border hydrolases (sucrase, maltase, leucine aminopeptidase and alkaline phosphatase) was followed as a function of both the time and the deoxycholate concentration. 1. Protein and enzyme release increased during deoxycholate perfusion only at concentrations greater than 0.5 mM. For each case, a plateau was reached at 2 mM deoxycholate. 2. After removal of deoxycholate from the perfusion fluid, the rate of protein and enzyme release dropped to the control levels. Following perfusion with 0.125 mM deoxycholate, however, there was a stabilizing effect so that the release rate of sucrase, maltase and alkaline phosphatase (but not of protein and leucine aminopeptidase) was smaller than that of the controls. 3. Protein and enzyme release was correlated with the deoxycholate-induced changes in surface tension. Significant increases in the release rates began between 0.5 and 1 mM deoxycholate when the surface tension fell below 50 dynes/cm. The plateau observed at or above 2 mM deoxycholate coincided with the stabilization of surface tension at 46 dynes/cm. 4. The maximum releasing effect also coincided with the critical micellar concentration of deoxycholate (1.5-2.5 mM).
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PMID:The relationship between surface tension and release of rat jejunal brush border membrane hydrolases induced by sodium deoxycholate. 676 Feb 81

The effect of vitamin D status on the topography of intestinal cell membranes was studied in isolated brush borders, as well as their purified membranes, by limited proteolysis. Addition of papain to brush borders isolated from vitamin D3-treated and deficient chicks resulted in a differential solubilization of leucine aminopeptidase, maltase, and sucrase activities (114, 195, and 79%, respectively, of appropriate control levels) but not alkaline phosphatase activity. In comparison, proteolysis of purified membranes exhibited vitamin D3- and 1,25-dihydroxycholecalciferol [1,25(OH)2D3]-dependent differences in release of all four marker hydrolases monitored. Calcium uptake studies revealed that preincubation with papain yielded vesicles with a calcium content that was 125% of corresponding native vesicles, in preparations from vitamin D3-treated, as well as deficient birds. Membrane vesicles prepared from 1,25(OH)2D3-treated chicks initially accumulated calcium to a greater extent than those from rachitic birds, but thereafter exhibited a decline in calcium content to basal levels. Preincubation with papain, however, abolished this loss of calcium. The combined results indicate that vitamin D mediates alterations in brush border protein topography and raise the possibility that this action of the seco-steroid might be involved in calcium absorption. However, if vitamin D-stimulated calcium transport across the brush border is dependent on a protein carrier, the molecular entity is not sensitive to inactivation by papain.
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PMID:Vitamin D-mediated alterations in the topography of intestinal brush border proteins: effect of papain on hydrolase release and calcium uptake. 684 6


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