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

The rat small bowel was perfused in vivo and ex vivo in the absence of biliary and pancreatic secretion. Intraluminal release of sucrase, alkaline phosphatase, aminopeptidases and enterokinase was significantly increased after administration of pentagastrin, caerulein and glucagon at doses ranging between 1 pg and 10 microgram. This suggests that there is a direct hormonal stimulation of the intestinal mucosa. This effect might at least partly be mediated through cyclic AMP since dibutyryl derivates of this cyclic nucleotide exerted a significant stimulatory effect on intraluminal release of proteins, sucrase and enterokinase, although the pattern of enzyme was quite different from the effect produced by the three peptides.
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PMID:Hormonal stimulation of intestinal brush border enzymes release. 20 30

The effects of corticosteroid have been studied in rats submitted to oral administration of prednisone (5 mg. per kg. per day) during 8, 15, 30, and 90 days. The results were compared to those obtained after parenteral administration of hydrocortisone acetate (50 mg. per kg. per day intramuscularly). The morphometric changes of the villus-crypt axis and the brush border enzymic content of the mucosa (sucrase, enterokinase, alkaline phosphatase, and aminopeptidase) were the parameters investigated at the duodenal, jejunal, and ileal levels. Oral administration of prednisone resulted in a significant increase of the duodenal villous height at the 15th (+ 13 per cent, p less than 0.01), 30th (+ 33 per cent, p less than 0.001), and 90th day (+ 56 per cent, p less than 0.001), whereas in the jejunum a constant decrease of the villous height was noted. Parenteral hydrocortisone administration did not affect intestinal morphology. Effects of oral corticosteroids on the microvillous enzymic activities were related to both intestinal level and duration of corticoids administration: (1) in the duodenum increase of sucrase, alkaline phosphatase, and aminopeptidase during 30 days followed by normalization at the 90th day, (2) an initial increase of sucrase, alkaline phosphatase, and aminopeptidase limited to the first 8 days in the jejunum, and (3) a significant rise of alkaline phosphatase (greater than 100 per cent, p less than 0.001) and enterokinase (greater than 100 per cent, p less than 0.001) in the ileum at the 15th day of treatment. Parenteral corticosteroid administration was associated with a significant increase of both sucrase and enterokinase activities. The present study suggests that: (1) Corticosteroids exert a direct effect on the intestinal morphology varying with the intestinal level and duration of treatment. (2) No correlation could be established between anatomic and functional changes. (3) Oral corticosteroids exert an enhancing effect of the brush border enzymic activities, even in the adult mucosa and particularly at the ileal level where they stimulate significantly the enterokinase mucosal activity. (4) Parenteral corticosteroids exert a more specific effect limited to sucrase and enterokinase enhancement.
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PMID:Effects of oral and parenteral corticosteroids on intestinal villous morphology and brush border enzymes in the rat. 31 75

1. Specimens of human duodenal mucosa were obtained at duodenotomy. Superficial mucosal scrapings were homogenized in isotonic sucrose solution and fractionated by differential centrifugation. The distribution of organelles among the subcellular fractions was monitored by assay of suitable marker enzymes. 2. Enterokinase was recovered predominantly in the nuclear+brush-border fraction and 80% of the total activity was found to be particulate; approximately 20% of the enzyme was present in the soluble fraction, compared with 1% of the brush-border markers sucrase and alkaline phosphatase. 3. The brush-border-containing fraction was subfractionated by treatment with hypertonic Tris followed by differential and density gradient centrifugation. Enterokinase was distributed among the subfractions in parallel with brush-border markers and was concentrated in a subfraction which was highly enriched in microvillous membranes. 4. It was concluded that enterokinase is localized primarily to the microvillous membrane of the epithelial cell brush border in man, but that in addition a proportion of the enzyme may be present in a soluble or easily released form in the duodenal mucosa.
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PMID:Subcellular localization of enterokinase in human duodenal mucosa. 58 40

In rats exposed to a long-term effect of carbon disulphide vapours in concentrations of 10 and 100 mg/m3 of air subject to a dynamic study were the activity of the enterokinase and alkaline phosphatase of the small intestine mucosa and feces, the presence of protein of non-alimentary origin and of the mucus in feces, coprocytograms, this being accompanied by a histomorphological verification of the microflora. In rats exposed to the effect of carbon disulphide in concentrations of 50 and 200 mg/m3 the studies covered parietal digestion by using as substrates carbohydrates and dipeptide. The degree of pathology was found to depend on the concentration of the toxic agent and the duration of priming.
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PMID:[Cavitary and parietal digestion in the action of a toxic agent on the animal organism]. 60 1

A micromethod for the isolation of brush border membrane fragments from single peroral duodenal biopsies, and their subsequent analysis by polyacrylamide gel electrophoresis is described. The quantity of biopsy material used varied between 5 and 15 mg wet weight, leaving enough mucosa for histological examination. By cutting the gels longitudinally into two halves it was possible to identify several maltases, sucrase, isomaltase and lactase and to correlate these enzymatic activities with distinct co-migrating protein peaks. For alkaline phosphatase and enterokinase this correlation was not possible. This method is suitable for the study on single biopsies of the molecular alterations occurring in the various congenital enzyme deficiencies of the human small intestine.
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PMID:A micromethod for separation and identification of digestive enzymes in brush border membrane fragments of single human intestinal biopsies. 66 14

The influence of parenteral nutrition on digestive tolerance was studied in 26 dogs receiving total abdominal irradiation, (1 110 rads were delivered in a single dose at mid-thickness of the abdomen). We studied enzymatic perturbations (lactase, maltase, alkaline phosphatase and enterokinase) in the duodenum, jejunum and ileum and we observed a correction of the 75% decrease of the intestinal enzymatic activities after total abdominal irradiation in the dogs fed exclusively by parenteral routes while the dogs fed orally died in few days with severe digestive and metabolic disturbances.
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PMID:Total abdominal irradiation and parenteral nutrition: an experimental study in the dog. 82 50

In rats fed equal amounts of isocaloric high-protein (HPR) and low-protein (LPR) diets, studies were performed on the mucosal activities of enterokinase and alkaline phosphatase and on the activities of these enzymes and of trypsin in washings obtained from the contents of two standard 5 cm. segments of duodenum, located proximal (Segment I) and distal (Segment II) to the main pancreatic duct. Mean mucosal weights and tissue protein per segment were 1.3-fold higher in rats fed HPR diets. In Segment I, but not Segment II, mucosal activities per segment were higher in HPR for enterkinase (threefold) and alkaline phosphatase (twofold). In luminal washings trypsin did not differ between the two groups; in HPR luminal levels of enterkinase were significantly higher in Segment II and those of alkaline phosphatase were similarly elevated in Segment I. Irrespective of diet the major activity of both enzymes was in mucosal fractions. Studies of total activity of each enzyme showed that the enzymes behave rather similarly, with the major differences between the dietary groups discernible in Segment I. These data stress the importance of dietary protein content in intestinal enzyme adaptation and reveal regional variation in the responses of the different enzymes.
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PMID:Alterations in enterkinase, trypsin, and alkaline phosphatase in response to variation in dietary protein content in the rat. 83 Jul 83

The subcellular localization of enterokinase is controversial. In this study, enterokinase was extracted from a soluble fraction and a brush border fraction of rat small intestine by differential centrifugation. The soluble fraction contained 41% of the initial enterokinase activity while the brush border fraction contained only 4.6% of the initial activity. In contrast, alkaline phosphatase monitored as a brush border marker, yielded 26.3% in the brush border fraction and only 6% in the soluble fraction. Further separation of the soluble fraction on a Sepharose 4B column revealed three peaks of enterokinase activity. One small peak (3%) of a bound enzyme (Mr, 2 - 10(6)) and two larger peaks of free enzyme (Mr, 3 - 10(5) and 9 -10). In contrast, alkaline phosphatase major fraction was in a high molecular weight peak of bound enzyme. When the brush border fraction was chromatographed only a single peak of bound enterokinase and alkaline phosphatase were found. In the lower part of the small intestine, no brush border-bound enterokinase was found, while the peak of alkaline phosphatase was the same as in the upper intestine. These data suggest that enterokinase activity in the rat intestine is mainly in a free form localized in the mucin and soluble fraction and to a negligible extent in the brush border.
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PMID:Subcellular localization of enterokinase (enteropeptidase EC 3.4.21.9) in rat small intestine. 87 77

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

Rat small bowel was perfused in vivo and ex vivo in the absence of biliary and pancreatic secretion. Intraluminal release of sucrase, alkaline phosphatase, aminopeptidase and enterokinase was significantly increased after administration of PG E1 and E2 1 and 5 microgram/kg. This suggests a direct stimulation of the intestinal mucosa, which might be mediated through cyclic AMP; dibutyryl cAMP significantly stimulates intraluminal release of proteins, sucrase and enterokinase.
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PMID:Prostaglandins E1 and E2 stimulate release of intestinal brush border enzymes. 90 72


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