Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.9 (enterokinase)
 675 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

The experiments on dogs have shown that during 3-5 weeks after resection of 1/3 and 2/3 of the pancreas the total amount of the excreted intestinal juice and the content of proper enteric enzymes in it (enterokinase, alkaline phosphatase and saccharase) are decreased. According to the author's data the activity of intestinal juice amylase and lipase being enzymes mostly of the pancreatic origin, transferred in the small intestine from blood, is enhanced due to impairment of the histo-hematic barrier in the region of the resected pancreatic stump. 2-3 months following resection of 2/3 of the pancreatic gland the amount of excreted intestinal juice was nearly unchanged, but the content of proper enteric enzymes was somewhat increased, as compared with background indices.
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PMID:[Secretory activity of the small intestine after resection of the pancreas]. 101 22

A study of the cavitary and membrane digestion of lipids, carbohydrates, proteins and data of the histological structure of the bioptate of the duodenal mucosa in 34 patients with chronic pancreatitis revealed the morphological picture of chronic duodenitis. This resulted in a reduction of the sorption properties of the intestinal epithelium that was manifested in a reduction of the rate of membranous digestion, mainly of lipids and lactose. Lesser degrees of protein, starch and saccharose hydrolysis were observed. Biopsy specimens of the duodenal mucosa showed a reduced activity of enterokinase and alkaline phosphatase. Antacids (almagel, phosphalugel), mineral waters ("Borzhomi", "Poliana Kvasova"), regeneration stimulators (Metacyl, retalil), agents stimulating the motor function (cerukal, reglan and oth.) are recommended for the complex treatment of concomitant duodenitis.
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PMID:[The functional-morphological changes in the duodenum in chronic pancreatitis]. 147 21

The change from relative digestive rest to the phase of digestion is characterized by various dynamics of the activity of enterokinase, amylase, and intestinal isoenzyme of alkaline phosphatase. The effect of the food stimulus in 3-hour immobilization can be considered antistress because the activity of the intestinal enzymes is almost the same as that in intact animals. It was found that the intestinal digestive enzymes become adapted to repeated short-term immobilization stress. Administration of alpha- and beta-adrenergic blocking agents changes the response of the digestive enzymes to stress by lowering their activity.
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PMID:[Digestive enzyme activity during immobilization stress and its pharmacologic correction with adrenoblockaders]. 257 68

Enterokinase and alkaline phosphatase activities in the duodenal juice and fecal extract of 37 strongyloidosis patients living in moderate climate and 17 inhabitants of the tropics have been studied. In 60.7% inhabitants of the regions with moderate climate and 80% from the tropics decreased enterokinase activity in duodenal juice has been observed, while the decrease in alkaline phosphatase activity in fecal extract has been noted in 87.8% and 71.4% cases, respectively. After convalescence from 1 to 6 months, no normalization of intestinal enzymatic activity has been observed.
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PMID:[Intestinal enzyme activity in patients with strongyloidiasis]. 261 8

Results of the studies of large intestine microflora, enterokinase and alkaline phosphatase activity in the feces of 298 children and adults suffering from trichocephaliasis are presented. Intestinal dysbacteriosis was observed in 51.7% cases, increased enterokinase activity, in 57.6% cases and increased alkaline phosphatase activity, in 55% cases. Enteric enzyme activity relation to the state of enteric microflora is demonstrated. Specific bephenium hydroxynaphthoate and mebendazole treatment was followed by increased dysbacteriosis and higher intestinal enzyme activity, especially in case of bephenium hydroxynaphthoate treatment. Normalization of the above-mentioned parameters was observed 90-120 days after the end of the treatment.
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PMID:[Microparasitocenosis of the intestines and the activity of intestinal enzymes in patients with trichocephaliasis during treatment]. 277 91

The quantitative release of enterokinase from isolated rat enterocytes following treatment with taurocholate-taurodeoxycholate, papain, chymotrypsin, elastase, carbamylcholine, and cholecystokinin-octapeptide was examined. Alkaline phosphatase and lactate dehydrogenase activities were evaluated simultaneously to check for specificity. Bile salts promoted a concentration-dependent release of all enzymes. Concomitantly, bile salts also led to cell destruction in proportion to the amount of enzymes released. Proteases caused the release of enterokinase and alkaline phosphatase with no concomitant increase of lactate dehydrogenase or cell lysis. At equal concentrations, papain released more enzymes than chymotrypsin and elastase. Chymotrypsin and elastase, however, led to higher ratios of enterokinase to alkaline phosphatase found in the media and suggested a selective release of enterokinase (EK) over that of alkaline phosphatase. Bile salts and pancreatic proteases together seem to have an additive effect of the release of EK. Carbamylcholine and cholecystokinin-octapeptide had no effect on enzyme release. These results suggested that pancreatic proteases are involved in the release of enterokinase by a selective action. Bile salts may also play a role through a nonselective detergent effect.
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PMID:Physiological factors controlling release of enterokinase from rat enterocytes. 390 6

Three enzymes of intestinal origin-enterokinase, alkaline phosphatase, and sucrase-were released into the perfused small intestinal lumen of the rat upon intravenous injection of the gastrointestinal hormone cholecystokinin-pancreozymin (CCK-PZ). The presence of bile in the perfusion fluid greatly augmented this release. The results suggest that a combined mechanism of enzyme liberation due to direct hormonal stimulation of the gut wall and further solubilization of released intestinal enzymes by bile may be responsible for the appearance of these enzymes in the gut lumen.
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PMID:Hormone-elicited enzyme release by the small intestinal wall. 504 Aug 34


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