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)

Human small bowel early organogenesis was studied by scanning electron microscopy and found to be correlated to brush border enzymology. The appearance of the brush border enzymes sucrase, lactase, and aminopeptidase (measured in a purified apical membrane fraction) coincides with the first outgrowth of villi (eight weeks). Alkaline phosphatase was detected at seven weeks. The content of these enzymes furthermore increased up to the 14th week when both sucrase and aminopeptidase activities were comparable with adult values.
Gut 1984 Sep
PMID:Early organogenesis of human small intestine: scanning electron microscopy and brush border enzymology. 643 34

Parenchymal cells isolated from rat liver are capable of taking up free hemoglobin. Uptake was saturable with a concentration for half-maximal velocity of 1.35 mg/ml (1.99 X 10(-5) M) hemoglobin. At a concentration of 0.088 mg/ml, the endocytic index for hemoglobin uptake was 4.5 microliters/h per mg of cell protein. This may be compared with the rate of fluid pinocytosis by these cells of 0.025 microliter/h per mg of cell protein (determined with yeast invertase as the marker). Free beta globin chains were also taken up with an endocytic index of 26.7 microliters/h per mg of cell protein at a beta chain concentration of 0.075 mg/ml. Hemoglobin inhibited the uptake of labeled beta globin. Hemoglobin-haptoglobin complex at a concentration of 0.12 mg/ml (as hemoglobin) was cleared at a rate of 0.89 microliter/h per mg cell protein and its uptake was also inhibited by free hemoglobin. We conclude that haptoglobin serves to conserve the iron of hemoglobin by preventing its renal clearance and not by promoting its hepatic uptake.
Biochem Biophys Res Commun 1984 Sep 17
PMID:Uptake of free hemoglobin by rat liver parenchymal cells. 648 98

Food was given to pigs before weaning to determine whether a hypersensitive response to dietary antigen might be a predisposing factor to postweaning diarrhea. Small amounts of food increased the severity and accelerated the onset of postweaning diarrhea. Postweaning diarrhea was dependent on the presence within the diet of antigenic material (bovine casein). A weaning diet, containing little antigenic material (hydrolyzed casein), had less effect on sucrase concentration in intestinal brush borders than did diets rich in antigens (native casein). Seemingly, immune-mediated intestinal damage may predispose the pig to postweaning diarrhea.
Am J Vet Res 1984 Sep
PMID:The importance of dietary antigen in the cause of postweaning diarrhea in pigs. 649 29

Activities of several carbohydrases and peptidases were determined in proximal, middle, and distal thirds of the jejunoileum of female 16-wk-old rats that were fed a high-starch (70 cal%), low-fat (7 cal%) diet for 2 wk and also in rats that (after this introductory period) were fed an isocaloric low-starch (5 cal%), high-fat (73 cal%) diet for 1, 2, and 3 days. The body weight changes, food intake, amount of protein per intestinal segment, and rate of enterocyte migration were practically the same in all groups during these experimental periods. The decreased intake of starch was followed by a rapid decrease (40-80%) of carbohydrases (lactase, sucrase, maltase, and glucoamylase) within the first 24 h in total intestinal homogenates--and as studied in cryostat serial sections--in all regions of the jejunal villus-crypt columns, and mainly in proximal and middle segments. In contrast, the activities of leucylnaphthylamidase and L-phenylalanylglycine hydrolase exhibited little change except for a slight temporary decrease of activity on the 1st day in the proximal segment only (25-30%). Thus these data show that a decrease of starch content in an isocaloric diet evokes a rapid decrease in the activity of microvillar carbohydrases and that activity of these enzymes both in mature and immature enterocytes is capable of reacting to a change (decrease) of dietary carbohydrate content.
Am J Physiol 1983 Sep
PMID:Dietary-induced rapid decrease of microvillar carbohydrase activity in rat jejunoileum. 661 86

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.
Pediatr Res 1983 Sep
PMID:Jejunal transport in experimental nephrotic syndrome. 662 9

The development of glucoamylase activity was compared to that of disaccharidase in the small intestinal mucosa of infants and children. By the age of one month, infants have glucoamylase and disaccharidase levels comparable to those of young adults, indicating that young infants may be able to digest and absorb starches. In infants and children with varying degrees of mucosal injury of the small intestine, the activities of glucoamylase decreased progressively with increasing severity of the villus atrophy. However, the reduction of lactase, palatinase, and sucrase activities was more severe than the loss of activities of glucoamylase and maltase. Thus, children and infants may tolerate polymers of glucose better than disaccharides when they have mucosal injury associated with prolonged diarrhea.
J Pediatr 1980 Sep
PMID:Glucoamylase and disaccharidase activities in normal subjects and in patients with mucosal injury of the small intestine. 677 72

Research into the activity of the enzymes invertase, gamma-amylase, alkaline phosphatase in the macrocolonies of the rat small intestine has shown that each macrocolony has stringently individual functional properties and the predominance of one of the enzymes. The data have been also obtained, indicating different rate of lysin and leucin absorption by the macrocolony epithelium of the small intestine. The results prove the existence of a definite functional differentiation of epitheliocytes (macrocolonies) arising from the same stem cell of the intestinal epithelium.
Biull Eksp Biol Med 1980 Sep
PMID:[Enzymatic differentiation and absorptive capacity of the epithelium of small intestine macrocolonies]. 677 7

Lactase and sucrase are two disaccharidases that differ not only in their substrate specificity and developmental patterns, but also in their resistance to mucosal insult. In this experiment, we tested the hypothesis that there might be a dichotomy in expression of enzyme activity along the jejunal villuscrypt unit. Sectioning of the villus-crypt unit in a cryostat enabled direct comparison of the distribution of lactase and sucrase enzyme activities in the adult rat. There is a stepwise increase in mean lactase/sucrase ratio going from crypt to villus. The data indicate that unlike sucrase activity, which is expressed maximally in enterocytes along the entire villus, maximal lactase activity is not attained until midvillus. The delay in expression of maximal lactase activity might help to explain the vulnerability of this enzyme to acute mucosal insult such as occurs in viral gastroenteritis.
Gastroenterology 1980 Sep
PMID:Demonstration of a difference in expression of maximal lactase and sucrase activity along the villus in the adult rat jejunum. 677 2

In infants suffering from protein-calorie malnutrition, the decreased intestinal mucosal lactase specific activity could be due either to the protein-calorie malnutrition or to the commonly associated enteritis (viral or bacterial) and intestinal parasites. We studied intestinal mucosal disaccharidase (lactase, sucrase, and maltase) specific activity in suckling (1 and 2 wk old), weanling (3 wk old), and postweaning (4 and 6 wk old) control and growth-retarded (malnourished) rats. Growth retardation was induced by feeding mother rats and postweaning rats a diet deficient in protein. In the malnourished rats, with few exceptions, specific activity of the disaccharidases in the intestinal mucosa were similar to those in the corresponding control groups of rats. However, because of marked mucosal atrophy total intestinal mucosal disaccharidase activities were more than 50% lower in the malnourished rats. These findings suggest that the specific activity of the intestinal mucosal disaccharidases is not affected by malnutrition per se.
Am J Clin Nutr 1981 Sep
PMID:Intestinal disaccharidases in malnourished infant rats. 679 98

Female rats of the Wistar strain, weighing 40-60 g were used to study the effect of fish meals (Coryphaenoides rupestris, Chimaera monstruosa and Merluccius merluccius) on the disaccharidases and alkaline phosphatase in the small intestine in relation to the control group which consumed casein. Fish meal diets diminished lactase and alkaline phosphatase activity, the latter being most remarkable in animals fed Ch. monstruosa meal, while no statistical variations in maltase and sucrase activity were observed. Maltase, sucrase and lactase activity of animals fed Ch. monstruosa meal dropped in comparison with those fed C. rupestris meal, while the alkaline phosphatase activity showed no significant changes.
Rev Esp Fisiol 1982 Sep
PMID:[Effect of various fish meals on disaccharidases and alkaline phosphatase of the small intestine in rats]. 681 26


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