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)

In vivo jejunal transport of amino acids, monosaccharides, sodium, and electrolytes were studied in rats made nephrotic with puromycin aminonucleoside (PAN) and in pair-fed controls. Studies were performed 14 days after a single intravenous dose of PAN when rats were no longer edematous, but were still hypoproteinemic. There was decreased absorption of glucose, 3-0-methyl glucose, glycine, phenylalanine, histidine, water, and sodium in the nephrotic animals but transport of fructose, lysine and potassium was similar in the nephrotic and control animals. Enzyme kinetic studies for glucose transport showed a mixed type of inhibition affecting both Vm and Km. The jejunal mucosa of nephrotic and control rats had similar ATP content and enzyme activity for lactase, sucrase, maltase and (Na-K)-ATPase and the ratios of RNA to DNA were similar in the nephrotic and control rats. No abnormality of the jejunum was detected by light or electron microscopy. The data suggest that the impairment of absorption is a result of decreased activity of jejunal membrane carrier mechanisms. The altered transport may be secondary to effects related to the metabolic consequences of nephrotic syndrome and does not appear to be related to acute purine aminonucleoside toxicity, edema or malnutrition.
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PMID:Jejunal transport in experimental nephrotic syndrome. 662 9

The effects of bilateral adrenalectomy and subsequent force-feeding of L-tryptophan (30 mg/100 g body weight) on the activity of disaccharidases (lactase, sucrase, and maltase) in the jejunum and ileum were investigated. One month after adrenalectomy the activity of lactase, sucrase, and maltase in the ileum and of lactase and maltase in the jejunum was significantly decreased when compared with that of the sham-operated controls. In adrenalectomized rats, administration of tryptophan (24 h later) produced significant increments in lactase and maltase activities in both jejunum and ileum, compared with the corresponding water-fed adrenalectomized control.
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PMID:Effect of adrenalectomy and tryptophan force-feeding on the activity of intestinal disaccharidases in adult rats. 677 Apr 55

To determine whether jejunoileal bypass operation and alcohol administration exerted a synergistic effect on the activities of brush border membrane enzymes and on liver morphology, adult rats where submitted either to sham operation or to jejunoileal bypass operation. 2 weeks after operation the rats received a 15% solution of ethanol during a period of 4 weeks, controls received water. In the sham-operated rats, alcohol provoked stimulation of the disaccharidase activities in the proximal jejunum but had no effect on these activities in the ileum. Bypass operation alone induced a significant increase in sucrase activity in the functioning ileum but had no effect on the jejunal disaccharidase activities. Alcohol administered after bypass provoked a further increase in ileal brush border sucrase activity. The increase of the brush border enzyme specific activities in the excluded loop resulted from the important protein loss observed in this segment. Alcohol alone or bypass operation by itself had little effect on liver morphology. In contrast, when associated they induced extensive accumulation of fat droplets in the hepatocytes. Since alcohol is frequently associated with the diet in man, alcohol should be considered as an important contributing factor to intestinal enzyme adaptation and liver dysfunction after jejunoileal bypass operation.
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PMID:Effect of chronic alcohol administration on liver morphology and on brush border membrane enzymes after jejunoileal bypass operation in rat. 681 78

Supragingival human dental plaque was collected from patients with evidence of caries. The plaque was frozen and stored at -20 degrees C. Pooled plaque was homogenized in acetate buffer pH 5.0 in an ice-water bath. By incubating the homogenate at pH 5.0 with [U-14C]-sucrose the formation of glucose and fructose was followed. Incubation in acetate buffer at pH 5.0 eliminated the glycosyltransferase activities and the glycolytic pathway. Normal Michaelis-Menten kinetics were observed until about 40 mM sucrose. At higher concentration of sucrose, excess substrate inhibition occurred. Storage of the homogenate at -20 degrees C resulted in decrease of the invertase activity with time.
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PMID:Method for determination of invertase activity in homogenates of human dental plaque. 695 Dec 45

The previously isolated recessive mutant allele hex2-3 of Saccharomyces cerevisiae caused a defect in carbon catabolite repression of maltase, invertase, malate dehydrogenase, and respiration but at the same time led to an extreme sensitivity to maltose (Zimmerman and Scheel, 1977; Entian and Zimmermann, 1980). Addition of maltose to a growing culture of a hex2-3 mutant resulted within 60 to 90 min in an inhibition of growth, glycolysis, and de novo protein synthesis. This was not accompanied by any abnormal levels of glycolysis metabolites or glycolytic enzyme activities. However, inhibitory effects coincided with a dramatic increase in intracellular glucose up to 150 mM relative to cell water as opposed to 2.5 mM in wild-type cells. This abnormal behavior is interpreted as a result of an uncontrolled maltose uptake in hex2 mutants, which in combination with increasing maltase activity results in an accumulation of intracellular glucose. Obviously the amount of available glucose surpassed glycolytic capacity in hex2 mutants. Properties of mutant alleles hex2 and hex1 (see Entian and Zimmermann, 1980) clearly show, that specific gene functions are involved in adapting the rate of sugar uptake into the cell to the actual glycolytic capacity.
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PMID:A defect in carbon catabolite repression associated with uncontrollable and excessive maltose uptake. 700 23

Organoleptic and some of the chemical parameters of sugar honey were compared with those of nectar beehoney. Rapid methods were devised to determine the main parameters characteristic of the soundness of beehoney. It was found that beehoney containing over 7% of saccharose may be regarded as feed, immature or sugar-falsified. In natural beehoney, the amount of saccharose, amylase (diastase) and invertase mainly depends on the degree of maturation and physiological status of the bee families during yield of honey. Sugar honey is characterized by the increased content of saccharose and water, reduced quantity of inverted sugar and low diastase activity.
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PMID:[Criteria for distinguishing sugar-adulterated honey from the natural]. 707 84

We compared the absorption of carbohydrate from solutions of glucose oligomers and glucose in jejunal Thiry-Vella fistulae, a preparation deprived of pancreatic secretions. The studies were performed with two concentrations (90 and 360 mg/dl) of both glucose and the glucose oligomers. Carbohydrate absorption from glucose solutions (33.1 +/- 2.8, 115.9 +/- 8.9 micrograms/cm/min) was significantly greater (P less than 0.025; P less than 0.005) than that from oligomer solutions (26.6 +/- 2.1 and 92.4 +/- 9.0 micrograms/cm/min). Thin-layer analyses of the perfusates demonstrate digestion of oligomers with a chain length up to eleven and suggest digestion of oligomers of even greater chain length. Atrophy of the jejunal mucosa occurred over the course of the study as evidenced by a decrease in the ratio of villous height to crypt depth from 3.8 to 0.3, and by a 80% decrease in the activity of maltase, sucrase, and lactase. Atrophy was accompanied by a significant decline in the absorption of both glucose oligomers (P less than 0.005) and glucose (P less than 0.01) from the more concentrated solutions but the decrement in absorption of both carbohydrates was similar: glucose oligomers, 79.3 +/- 19.4 micrograms/cm/min; and glucose, 69.8 +/- 14 micrograms/cm/min (P greater than 0.20). Water absorption was enhanced by both carbohydrates, but there was no demonstrable difference between solutions of glucose and glucose oligomers. The osmolality of the solutions clearly influenced water absorption (P less than 0.025) but failed to effect the absorption of carbohydrates.
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PMID:The jejunal absorption of glucose oligomers in the absence of pancreatic enzymes. 722 Jan 47

Ischaemia of the dog intestine lasting 1 h causes desquamation of the epithelium at the villus tips and congestion in the villus capillaries. The crypt cells are relatively undamaged. These changes are associated with a loss of active transport of organic solutes, determined in vitro, a reduction in mucosal sucrase activity and an abolition of glucose absorption in vivo. A profuse net loss of water and electrolytes into the lumen in vivo develops. The net sodium loss is due primarily to an inhibition of the lumen-blood flux of this ion, the blood-lumen flux being relatively unchanged. In uraemic dogs, the loss of urea into the lumen is the same in control and ischaemic loops, testifying to the lack of change in the unidirectional water flow from blood to lumen. Perfusion of the dog intestine with 1% Triton X-100 leads to morphological changes that have certain similarities with those provoked by ischaemia. Damage was restricted to the villus tips, protection from further alterations apparently being provided by a mucus layer that forms on the mucosal surface; the crypt region remained unchanged. After 10 min exposure, organic solute transport in vitro and glucose absorption in vivo were both reduced by not abolished; sodium and water absorption in vivo were suppressed, but no net secretion occurred. To account for these observations, we have suggested that the normal crypt cell is a secretory element with respect to sodium and water. During maturation, its absorptive properties develop such that the mature enterocyte, possessing both absorptive and secretory mechanisms, is capable of net absorption of sodium. After destruction of the villus tips, net secretion continues in the crypts; if there are insufficient villus cells remaining to ensure reabsorption, a net secretory capacity is observed.
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PMID:Source of net water and electrolyte loss following intestinal ischaemia. 736 61

Two studies using broiler chicks and one using adult White Leghorn roosters were conducted to determine the influence of stachyose and raffinose (alpha-galactosides of sucrose) present in soybean meal (SBM) on the nutritional value of the meal. In Experiment 1, the addition of four levels (0, .05, .10, or .20 g/kg) of alpha-galactosidase with and without 1 g/kg of invertase to a corn-SBM diet had no effect on weight gain, feed efficiency, protein digestibility, or the digestible energy value of the feed when fed to broiler chicks. However, both enzymes decreased (P < .001) dietary AMEn. In Experiment 2, ethanol extraction and incubation of SBM with alpha-galactosidase decreased the concentrations of the alpha-galactosides of sucrose in SBM from 6.59 to .81 and 1.43%, respectively. However, when broiler chicks were fed semi-purified diets containing SBM, ethanol-extracted SBM, water-incubated SBM, or water plus alpha-galactosidase-incubated SBM, no improvements in weight gain, feed efficiency, or apparent protein digestibility were observed. There was also no improvement in TMEn when the above meals were precision fed to adult White Leghorn roosters (Experiment 3). These results indicate that the removal of up to approximately 90% of the alpha-galactosides of sucrose has no beneficial effect on the nutritional value of SBM for chickens.
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PMID:Removal of the alpha-galactosides of sucrose from soybean meal using either ethanol extraction or exogenous alpha-galactosidase and broiler performance. 750 93

Cadmium compounds are found widely in our environment: for example, in food, water, soil, and ambient air. The most important exposure route of animals to cadmium in the general environment is via oral exposure. In oral cadmium intoxication, the immediate target organ is the gastrointestinal tract. The aim of the present work was to determine how cadmium acts on the intestinal absorption of sugars and on the sucrase activity through rabbit jejunum, after in vitro administration and/or oral administration of CdCl2 in drinking water. Results obtained show that cadmium decreases D-galactose accumulation in the jejunum tissue. This effect seems to be the results of an action mainly located on Na(+)-dependent sugar transport of the mucosal border of the intestinal epithelium, because cadmium seems not to modify the sugar diffusion across the intestinal epithelium. Cadmium has also been shown to inhibit the (Na(+)-K+)-ATPase activity of the enterocyte, which might explain the inhibition of the D-galactose Na(+)-dependent transport. Nevertheless, a direct action of the cadmium molecule on the Na(+)-dependent carrier cannot be discarded. Cadmium altered the sucrose activity when it was administered in the drinking water for 4 d.
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PMID:Effect of cadmium on enzymatic digestion and sugar transport in the small intestine of rabbit. 750 39


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