Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A modified Roux-en-y repositioning of rat proximal small intestine resulted in a gut segment (A) exposed only to digestive secretions, but not to food and a gut segment (B) exposed to food, stomach juice and by reflux only to digestive secretions, and a third segment (C) exposed to both, food and digestive secretions. The changes in segment A were qualitatively very similar to those occurring after removal of luminal nutrition (intravenous feeding, self-emptying blind loop, and Thiry Vella loop). These findings support the hypothesis that the presence of luminal nutrition is a major factor regulating mucosal mass and enzyme activity in rat proximal small intestine. The changes in the luminal environment in segment B caused an increase in mucosal mass (in the proximal half only), an increase in sucrase activity which paralleled the increase in mucosal mass, and no change in activity of alkaline phosphatase which in fact was a decrease in activity ;at the cellular level'. Later on the net absorption of sodium and potassium was improved and the disappearance of galactose was unchanged when referred to unit length of small intestine.In segment C there was a small increase in mucosal mass, an increase in activity only for alkaline phosphatase, and an improvement of the net absorption of sodium without changes in the disappearance of galactose. These changes were compatible with a more proximal promotion of a distal gut segment.
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PMID:Analysis of the effects of food and of digestive secretions on the small intestine of the rat: III. Mucosal mass, activity of brush border enzymes, and in vivo absorption of galactose, sodium, and potassium. 68 Jun 2

Intravenous administration of 1 U cholecystokinin-pancreozymin (CCK-PZ) to rats caused the release of enteropeptidase, alkaline phosphatase (AP), and sucrase to the intestinal lumen in the absence of a concomitant increase in luminal DNA. Thus, the hormone elicited hydrolase secretion was not due to cell desquamation. Pentagastrin also stimulated hydrolase release. Following CCK-PZ administration enteropeptidase was released preferentially over sucrase and AP and showed a linear correlation with total protein output. The specific enteropeptidase activity was higher in the perfusate following secretion than in the mocosa. Enteropeptidase was found mainly in soluble form in both mucosa and perfusate; addition of bile following enteropeptidase release further increased its activity. In contrast, sucrase and AP were found mainly in insoluble form in both mucosa and perfusate and their specific activities were higher in the mucosa. The presence of bile rendered both sucrase and AP more soluble in the perfusate. The data indicate that enteropeptidase is released by a specific secretory process and that its subcellular site of origin is different from that of sucrase and AP. By eliciting the coordinated release of trypsinogen, enteropeptidase and bile, CCK-PZ plays a central role in the initiation of protein digestion.
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PMID:Studies on intestinal enzyme secretion; the action of cholecystokinin-pancreozymin, pentagastrin and bile. 68 84

Brush-border membranes were isolated from the rat small intestine and then treated with sodium dodecyl sulphate under non-reducing conditions at room temperature. Analysis of the solubilized components by polyacrylamide-gel electrophoresis identified three major glycoproteins that co-migrate with glucoamylase-maltase-sucrase, lactase and isomaltase-maltase-sucrase activities. High activities of alkaline phosphatase and trehalase were detectable, but they could not be attributed to distinct co-migrating protein bands. Analysis of mucosa from the distal small intestine by the same methods showed a pattern of bands different from that obtained with the proximal intestine, which appeared to correlate with the relative deficiency of some of the enzymes in the distal region.
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PMID:The identification of rat intestinal membrane enzymes after electrophoresis on polyacrylamide gels containing sodium dodecyl sulphate. 69 63

1. Rats were fed with the elemental diet Vivonex for 1 or 3 months and their jejunal histology was compared with that of an equal number of rats fed on a normal diet. 2. After 1 month of Vivonex feeding a significant reduction in the ratio of crypt height: villus height (CH:VH) was found in the Vivonex-fed rats (n = 4) compared with the control rats (n = 4) (P less than 0.05). 3. After 3 months the CH:VH ratio was also reduced in the Vivonex-fed rats (n = 18) compared with control rats (n = 18) (P less than 0.002). Villus height was significantly increased (P less than 0.002) and crypt height decreased (P less than 0.05). 4. Jejunal protein content, alkaline phosphatase and disaccharidase activity were also determined in 12 control and 12 Vivonex-fed rats from the 3 months study. 5. Alkaline phosphatase activity was increased from a control value of 201 +/- 8 to 243 +/- 15 munits/cm in the Vivonex-fed rats (n = 12) (P less than 0.05) but no significant changes in lactase, sucrase or maltase activites were found. The observed decrease in the CH:VH ratio suggested an improved survival of the mature enterocyte population during elemental diet feeding.
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PMID:Small-intestinal changes induced by an elemental diet (Vivonex) in normal rats. 72 6

When rats are hypophysectomized in neonatal life, the growth of the small intestine is more severely retarded than the growth of the body as a whole. It was shown previously that intestinal growth is not rectified by doses of cortisone and/or throxine that restore normal activity of brush border enzymes in hypophysectomized sucklings; growth hormone did not affect relative weight or enzyme activity. Reexamination of this problem with much lower doses of hormones than previously employed has now shown that relative weight of the intestine is enhanced by cortisone and thyroxine together, and is normalized by cortisone and thyroxine in combination with rat growth hormone. Growth induced by treatment with the three hormones involved increases of crypt depth and villus height, and of mitotic index. Body weight was not affected by hormonal treatment, but the tails of the hypophysectomized sucklings were significantly lengthened by thyroxine alone, the effect being enhanced when growth hormone was also given. The physiological dose of hormones used in the present study were as effective in elevating activity of alkaline phosphatase and sucrase as the larger doses previously used. Cortisone had a greater effect on sucrase, thyroxine on phosphatase. Pentagastrin did not influence either growth or enzyme activity.
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PMID:Hormonal influences on the growth and enzymic differentiation of the small intestine of the hypophysectomized rat. 75 Mar 12

The effect of 8-hydroxyquinoline, a rapid inhibitor of RNA synthesis, was followed on the activity of a number of enzymes in cultures of the fission yeast Schizosaccharomyces pombe. Two types of effect were found. In the first the activity continued to rise for a period and then remained constant. This occurred with alkaline phosphatase, basal and derepressed acid phosphatase, hexokinase, and derepressed sucrase and maltase at low cell density. It is consistent with control being exercised by an unstable mRNA or by an unstable stimulator of translocation. In the second the activity increased above the control values for several hours. This occurred with basal sucrase and maltase, and suggests a stable mRNA and an unstable inhibitor of translation. The extent of 'superproduction' of sucrase varied with cell density and with growth medium and this may be due to differences in the degree of translational inhibition. The possiblilty of a stable mRNA has interesting implications for the control of enzyme synthesis through the cell cycle.
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PMID:The effect of 8-hydroxyquinoline on enzyme synthesis in the fission yeast Schizosaccharomyces pombe. 81 99

The effects of carbohydrate intake on jejunal disaccharidases in rats with chronic mannitol-induced, osmotic diarrhea were studied. Weanling rats were force-fed 5 ml/100 g of body weight of water of 20% mannitol (w/v 1300 mOsm) daily for up to 14 days. Diets containing 70% of either starch, sucrose, glucose, or 20% lactose with 50% starch were fed ad libitum. Mannitol-fed rats had increased water intake and diarrhea. They gained weight, but less than controls. The levels of intestinal disaccharidases in mannitol-fed rats were related to dietary carbohydrate intake. Seven days of mannitol treatment led to lactase and sucrase deficiencies in rats fed starch whereas jejunal maltase and alkaline phosphatase were unchanged. Deficiencies in lactase and maltase but not in sucrase were induced when rats were fed a sucrose diet, while a decrease only in sucrase occurred in rats fed a lactose-starch diet. Rats with mannitol-induced diarrhea fed a glucose diet had reduced levels of all disaccharidases. The changes in intestinal disaccharidases were not associated with alterations in the number of epithelial cells or ultrastructural abnormalities. 3H-thymidine incorporation into DNA following 7 days of mannitol treatment was similar to water-fed controls. Absorptive epithelial cells were not damaged and the microvilli were normal in height and appearance. These data suggest that the levels of specific disaccharidases show and enhanced dependence upon the corresponding dietary substrates during diarrhea induced by an osmotic load.
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PMID:Interaction between dietary carbohydrates and intestinal disaccharidases in experimental diarrhea. 85 Oct 74

The separation by polyacrylamide gel electrophoresis and subsequent enzymatic analysis of the components of the guinea pig intestinal brush border membrane revealed the presence of three enzyme complexes: maltase-glucoamylase, maltase-sucrase-glucoamylase and maltase-sucrase. Additional bands possessing lactase, trehalase and alkaline phosphatase activity were identified but no phlorizin hydrolase or palatinase was detectable. After exposure to strong dissociating conditions the bands possessing enzymatic activity were either absent or greatly reduced in intensity.
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PMID:Glycosidases of the guinea pig brush border membrane. 86 Dec 25

Widely used methods in diagnostical and experimental gastroenterology like measuring the protein-and DNA-content and the activity of alkaline phosphatase and sucrase of intestinal mucosa were adapted to a microliter system and partly automatized. With "artificial" control material a system for statistical quality control was established. Lastly the results on up to three years experience with this control system were presented showing an imprecision within run below 5% and an in-imprecision between run below 8% in all methods.
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PMID:Measurement of enzyme activity and substrates in intestinal mucosa. Evaluation of a system for quality control in clinical and experimental gastroenterology. 88 67

The incorporation of [14C]glucosamine into brush border glycoproteins by human small intestinal mucosa in organ culture has been investigated. The experiments were based on the observations that (1) isolated brush border membrane fragments from cultured explants showed an unchanged pattern of protein bands and brush border enzyme activities on sodium dodecyl sulfate/polyacrylamide gels after electrophoresis and (2) the rate of overall [14C]glucosamine incorporation measured in the tissue homogenate remained constant up to 48 h. After 24 h of culture, the radioactivity peaks on gels due to incorporation of [14C]glucosamine were found exclusively in the high molecular weight region and corresponded to protein bands identified as maltase-glucoamylase, lactase, sucrase-isomaltase, enterokinase and alkaline phosphatase. Enzymatic activity could not be assigned to the three remaining labelled bands. Most of these glycoproteins were already labelled after 5 h. Newly glycosylated brush border enzymes remained predominantly associated with the brush border membrane of intact cells with little release into the medium up to 24 h.
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PMID:Biosynthesis of brush border glycoproteins by human small intestinal mucosa in organ culture. 88 74


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