Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.108 (lactase)
 2,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Disaccharidase activities of the small-intestinal brush border membrane were studied in six laboratory lines of the house musk shrew, Suncus murinus. 2. Sucrase activity was detected in all shrews of one line, but not in any shrew of three lines. In the other two lines it was found in some shrews, but not in the others. 3. Maltase, isomaltase, trehalase and lactase activities were found in all shrews of all the lines examined. 4. Sucrase was normally associated with isomaltase to form an enzyme complex. 5. Detergent-solubilized isomaltase, whether associated with sucrase or not, was inhibited by antibodies against rabbit sucrase-isomaltase to almost the same extent as the rabbit one, suggesting that isomaltase is not affected by a mutation(s) in sucrase.
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PMID:Intestinal disaccharidases in the house musk shrew, Suncus murinus: occurrence of sucrase deficiency. 145 37

The activities of four disaccharidases were examined in resistant (C57Bl/6) and susceptible (C3H/HeN) mice during the primary infection with Giardia muris and after challenge with either trophozoite extract or cysts. Significant decreases in lactase, sucrase, trehalase, and maltase activities in C57Bl/6 mice and lactase and sucrase activities in C3H/HeN mice in the anterior 25% of the small intestine were observed on day 10 after infection. The activities of maltase, sucrase, trehalase, and lactase in the jejunum of C3H/HeN mice were significantly reduced after challenge with trophozoite extract, when compared with the uninfected or infected, but not challenged animals. Decreases in enzyme activities of C3H/HeN mice were evident as early as 12 hours after challenge with the extract. The resistant C57Bl/6 mice showed little change in disaccharidase activity after challenge with trophozoite extract. On the other hand, challenge with cysts resulted in a few decreases in disaccharidase activities in both strains of mice: C57Bl/6 mice showed decreases in the duodenum, while disaccharidases of C3H/HeN mice had lower activity more posteriorly. Thus, challenge with parasite antigen results in a more severe disaccharidase deficiency in susceptible hosts when compared with resistant ones.
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PMID:Disaccharidase activity in the small intestine of susceptible and resistant mice after primary and challenge infections with Giardia muris. 153 93

Twenty (12 Holstein, 8 Longhorn cross) calves (198 kg and 7 mo old) were used in a randomized complete block design to evaluate the effects of dietary forage concentration and feed intake on carbohydrase activities and small intestinal (SI) morphology. Calves were individually fed 90% forage (alfalfa) or a 90% concentrate (50% sorghum: 50% wheat) diet at either one or two times NEm for 140 d and slaughtered; tissues and small intestinal digesta were collected. Increased feed intake increased (P less than .05) pancreatic weight, alpha-amylase and glucoamylase activities in the pancreas, SI length and SI digesta weight. Forage-fed calves gained faster (P less than .01) and had greater (P less than .05) pancreatic protein concentrations, alpha-amylase and glucoamylase activities in the pancreas and greater SI digesta alpha-amylase activities than grain-fed calves did. Increased feed intake increased (P less than .01) mucosal weight/cm small intestine only in forage-fed calves and increased (P less than .05) SI surface/volume only in grain-fed calves. Mucosal weight was greatest (P less than .05) at the terminal ileum, surface/volume was greatest (P less than .05) in the duodenum, and mucosal protein concentration was highest (P less than .05) in the SI mid-section. Mucosal lactase was higher (P less than .05) in proximal segments, whereas mucosal isomaltase was higher in middle and distal segments of the small intestine. For mucosal maltase activity, there was a feed intake x SI sampling site interaction (P less than .05) and for trehalase, a diet x feed intake x SI sampling site interaction (P less than .05). The SI distribution patterns of maltase and isomaltase were similar, as were those of trehalase and lactase. The alpha-amylase activity in the pancreas and SI morphology were influenced greatly by diet composition and feed intake by calves.
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PMID:Influence of dietary forage and feed intake on carbohydrase activities and small intestinal morphology of calves. 169 58

The present study intended to evaluate the influences of Metagonimus yokogawai on the activities of brush border membrane bound enzymes of the small intestine. Mice were infected with 500 metacercariae respectively, and the worm recovery, morphological changes and enzyme activities were observed chronologically. A part of them were followed after the treatment. Recovered worms decreased in number continuously after the infection, and they were less than 10% after 2 weeks and almost zero after 28 weeks. Villous atrophy and stromal inflammation were found at two locations of the proximal jejunum from 2 weeks to 4 weeks after the infection. The enzymes, alkaline phosphatase, leucine aminopeptidase and disaccharidases (sucrase, lactase, maltase, and trehalase), showed lowered activities in the duodenum and proximal jejunum of the infected mice but they increased in the distal jejunum for the first two weeks. From three weeks after the infection, the activities were gradually recovered. In one week treated mice, they recovered the activities at 2 weeks from the treatment, but there found no differences of the activities between the 3 week treated group and infected controls. The present data reveal that M. yokogawai infection induces degenerative changes of the host's intestinal mucosa not only morphologically but functionally during the initial phase of infection. The lowered enzyme activities in acute metagonimiasis should be associated with malabsorption and diarrhea.
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PMID:Activities of brush border membrane bound enzymes of the small intestine in Metagonimus yokogawai infection in mice. 191 29

Acute uremia was induced in rats with temporary clamping of the left renal pedicle and contralateral nephrectomy. Jejunal peptidase activities (aminopeptidase N, dipeptidyl peptidase IV and aminopeptidase A), disaccharidase activities (maltase, sucrase, lactase and trehalase) and morphology were studied. A significant (p less than 0.05) increase in aminopeptidase N activity and a positive correlation between aminopeptidase N activity and serum urea was found in the uremic rats. The other peptidase activities showed a slight increase in the uremic rats. A shortening of the microvilli of the small intestinal epithelial cells in the uremic rats was seen by electron microscopy. The disaccharidase activities was unaltered. This study shows the presence of functional alterations in the small intestine in rats with acute uremia. The observations are also compatible with different regulation mechanisms for the brush border peptidases and disaccharidases.
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PMID:Small intestinal peptidases and disaccharidases in rats with acute uremia. 192 11

Intestinal lactase activity in mammals is high at birth but begins to decline around weaning and reaches very low levels in adult life. The triggering mechanism for this decline is not clear. Because of the association of the decline with weaning, lack of lactose in the diet has been implicated. In 110 growing rats, the effect of continued supplementation of the diet after weaning with physiological amounts of either cows' milk or a 5% lactose solution on intestinal lactase and other disaccharidase enzyme activities was investigated. In both control and test animals, the specific lactase activity decreased from a peak value of 115 +/- 4 mumol min-1 g-1 protein before weaning to about 10% at maturity. There was no significant difference in the level or the pattern of decline between the groups. Sucrase, maltase and trehalase showed the normal maturational changes without being affected by the test diets. The finding suggests that diet, particularly the presence or absence of physiological amounts of lactose, has no appreciable effect on the age related spontaneous decline of intestinal lactase activity or on the pattern of development of the other disaccharidases.
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PMID:The effect of continued feeding of physiological amounts of lactose on the level of intestinal lactase and other disaccharidase enzyme activities in the rat. 211 Nov 52

In order to establish whether an enzymatic method (a "functional" test) could be used instead of the histological picture as an indicator of damage to enterocytes of duodenal mucosa, biopsies were taken from 39 patients with upper gastrointestinal symptoms suggestive of peptic ulcer disease, but without active ulcers at endoscopy. Eleven patients with a normal appearance of the duodenal bulb mucosa and twenty-eight patients with various degrees of endoscopic inflammation ("bulbitis") were evaluated. The histological degree of duodenitis was assessed, and the activities of maltase, invertase, trehalase and lactase in the biopsy specimens were measured. Disaccharidase activities were inversely proportional to severity in both endoscopic and histological scoring of degree of inflammation. Low disaccharidase activities were also present in patients with endoscopic inflammation of the duodenal bulb, but without histological duodenitis. Focal and especially widespread gastric metaplasia was, in itself, significantly associated with low disaccharidase activities. The correlation between endoscopic and histologic scoring of inflammation of duodenal mucosa was not significant as assessed by kappa statistics. A previous history of peptic ulcer disease was significantly more common in patients with, than in those without, endoscopic inflammation of the duodenal bulb.
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PMID:Low activities of disaccharidases associated with inflamed duodenal bulb mucosa. 211 Dec 72

Two hundred and ninety four duodenal and jejunal mucosal biopsy specimens from patients with coeliac disease, treated and untreated, and other conditions were examined histologically and by histochemical staining for five peptidase and three disaccharidase enzymes to determine profiles of activity. Suppression of activity paralleled the histology with the following enzymes: lactase, trehalase, brush border endopeptidase, dipeptidyl peptidase II and isomaltase. Lactase, trehalase, and brush border endopeptidase were specifically suppressed in untreated coeliac disease and were diagnostically useful. Examination of a combination of enzymes is recommended.
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PMID:Brush border enzymes in coeliac disease: histochemical evaluation. 218 3

The effect of supplementation of the diet with galactose on the age-related decline of intestinal lactase activity was investigated in 108 growing rats. Starting from 14 days of age, the rats were divided into two groups and fed with chow, and with fluid either as tap water or 5% galactose solution. At 14 days the specific lactase activity was 112.8 +/- 3.2 mumol min-1 (g protein)-1, which decreased to less than 10% of this value at maturity. Galactose supplementation did not prevent the decline. The increase of maltase, sucrase and trehalase was also unaffected. The result suggests that galactose plays no significant role in the regulation of disaccharidase activities in the rat.
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PMID:The effect on intestinal disaccharidase activity of feeding galactose to growing rats. 224 21

Three pseudo-aminosugars, validamine, valienamine and valiolamine, produced by Streptomyces hygroscopicus subsp. limoneus showed potent inhibitory action on rat small intestinal carbohydrase activities such as sucrase, maltase, glucoamylase, isomaltase and trehalase activities, but negligible action on lactase activity and pancreatic alpha-amylase activity. Where inhibition was seen, kinetic analysis showed fully competitive inhibition of the carbohydrase activities by all three inhibitors. Valiolamine has more potent carbohydrase inhibitory activity than validamine or valienamine, and the apparent Ki values of valiolamine for sucrase, maltase, glucoamylase, isomaltase and trehalase activities were 3.2 x 10(-7), 2.9 x 10(-6), 1.2 x 10(-6), 9.1 x 10(-7) and 4.9 x 10(-5) M, respectively, which are 10(-5) to 10(-3) times smaller than the apparent Km values.
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PMID:Inhibitory effect of validamine, valienamine and valiolamine on activities of carbohydrases in rat small intestinal brush border membranes. 226 98


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