Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The neutralization of acid introduced into the duodenum has been found to be less intensive in patients with duodenal ulcer than in controls. The present work studied the possibility that chronic gastric hypersecretion injures the duodenal mucosa and thereby influences the neutralization system. Gastric hypersecretion was provoked for 3 weeks in 3 dogs by a daily injection of a gastrin preparation with prolonged effect. After a subcutaneous injection of this preparation given together with a test meal the acidity of both gastric and duodenal contents was found to increase significantly. After the 3 weeks of gastric hypersecretion the pancreatic bicarbonate response to exogenous secretin was unchanged, while the bicarbonate response to duodenal acidification was decreased from 2.03 mEq/30 min to 1.27 mEq/30 min (p less than 0.05), compatible with an impaired secretin release. Also the concentration of lactase, maltase, sucrase, and alkaline phosphatase in mucosal biopsies from the second part of the duodenum was significantly reduced (p less than 0.001). These results indicate that gastric hypersecretion causes mucosal damage in the duodenum and thereby reduces the release of secretin.
 ...
PMID:Effect of gastric hypersecretion on the canine duodenum. 1 Jun 21

Digestive enzymatic activities (disaccharidases, alkaline phosphatase, peptide hydrolases) have been determined in the mucosa of 14 patients with chronic pancreatitis. All had an abnormal secretin-pancreozymin test. Four patients had insulin-dependent diabetes mellitus, four a pathological glucose tolerance test. Nine patients had steatorrhoea. Maltase, sucrase, and alkaline phosphatase activity was significantly elevated in patients with exocrine pancreatic insufficiency, whereas those of lactase, trehalase, and peptide hydrolase were normal. Patients with steatorrhoea had higher maltase and sucrase activity than those without steatorrhoea, whereas decreased glucose tolerance had no effect on brush border enzymatic activity. It is suggested thatdecreased exocrine rather than decreased endocrine pancreatic function is responsible for the increase in intestinal disaccharidase and alkaline phosphatase activity, possible by the influence of pacreatic enzymes on the turnover of brush border enzymes from the luminal side of the mucosal membranes or by direct hormonal stimulation though cholecystokinin.
 ...
PMID:Influence of exocrine and endocrine pancreatic function on intestinal brush border enaymatic activities. 109 2

Glucagon is structurally related to secretin but inhibits the effects of secretin and cholecystokinin (CCK) on pancreatic secretion in vivo. Because secretin is a weak stimulant of pancreatic growth and potentiates the trophic effects of CCK, we hypothesized that glucagon might inhibit CCK-induced pancreatic growth. Four groups of 10 rats were injected with saline, glucagon (30 micrograms/kg, equimolar to a known trophic dose of secretin), cerulein (0.67 microgram/kg), or glucagon plus cerulein every 8 h for 5 days. The pancreas was excised, weighed, and assayed for total content of DNA, protein, amylase, chymotrypsinogen, and lipase. In control and glucagon-alone groups, the small intestine was also removed, weighed, and assayed for DNA, protein, and disaccharidase content. Glucagon alone decreased pancreatic DNA and increased lipase content. Compared with cerulein-treated animals, animals treated with glucagon and cerulein showed significant decreases in pancreatic weight and content of protein, amylase, and chymotrypsinogen. Although glucagon had significant effects on intestinal protein, maltase, and sucrase contents in certain segments, there was no clear pattern of response. The data suggest that glucagon may be an inhibitory regulator of pancreatic growth, acting to block the effects of CCK on pancreatic hypertrophy.
 ...
PMID:Glucagon inhibition of cerulein-induced hypertrophy of the exocrine pancreas. 336 38

The effect of pentagastrin, secretin and cholecystokinin on biochemical parameters of mucosal growth and differentiation was studied in organ cultured rabbit jejunum and ileum. Pentagastrin at 0.05-5.0 microgram/ml did not affect DNA content of the biopsy, but led to a significant decrease of sucrase and alkaline phosphatase activity in the ileum. Secretin prompted a significant decrease of DNA and protein in the ileum at a level of 10(-7) and 10(-5) M, but had no effect in the jejunum. Of the brush border enzymes, sucrase and alkaline phosphatase were suppressed in both parts of the intestine both with respect to specific activity and total biopsy content. Cholecystokinin, like pentagastrin, did not influence DNA or protein content, but reduced sucrase, maltase and alkaline phosphatase activity. HMG-CoA reductase, the key enzyme of cholesterol synthesis, was not significantly affected by any of the three hormones tested. When brush border enzymes or DNA from desquamated cells were measured in the post-culture medium, no consistent effect of any gastrointestinal hormone was apparent. The present study demonstrates a direct "antitrophic" effect of secretin in cultured mucosa. Pentagastrin and cholecystokinin did not influence mucosal DNA content in vitro but apparently inhibited villus cell differentiation.
 ...
PMID:Effect of pentagastrin, secretin and cholecystokinin on growth and differentiation in organ cultured rabbit small intestine. 372 4

Five Beagle dogs, equipped with duodenal and gastric fistulae, were fed a standard diet before receiving the same diet supplemented with wheat bran for 1 month. Pancreatic secretory investigations performed in conscious animals before and 1 month after bran administration showed a significant parallel increase in the flow rate of pancreatic secretion and the outputs of bicarbonate and amylase both in basal and secretin-stimulated conditions. The outputs of protein and chymotrypsin increased only in unstimulated secretions, while the output of lipase was strongly reduced in response to secretin. However, the small intestinal mucosa was not affected by bran administration. Dietary fiber did not alter the height of the villi or the activity of sucrase, maltase and aminopeptidase in mucosal homogenates or isolated brush border membranes from intestinal biopsies. These data suggest that wheat bran supplemented to the standard diet affects the exocrine pancreatic secretion but not intestinal enzyme activities involved in the absorption of carbohydrates and proteins in the dog.
 ...
PMID:Effects of wheat bran on the exocrine pancreas and the small intestinal mucosa in the dog. 620 61

To determine the prevalence of short polymers of glucose and starch malabsorption caused by small intestinal glucoamylase deficiency in children with chronic diarrhea, we studied small bowel biopsy specimens from 511 children (aged 1 month to 9 years) with chronic diarrhea evaluated at 54 medical centers. Glucoamylase and disaccharidase (lactase, sucrase, maltase, and palatinase) enzyme assays were performed. Of the 511 children, 15 had glucoamylase deficiency. Six who had significant small intestinal mucosal injury and disaccharidase deficiencies were defined as having secondary glucoamylase deficiency; the other nine patients with normal mucosal morphologic features were defined as having primary glucoamylase deficiency. Secretin tests showed normal pancreatic amylase values for age in all seven children tested. Four of them had abnormal findings on tolerance tests for starch and short polymers of glucose (rise in blood glucose concentration: < 20 mg/dl) and reducing substances in stools, and three of these four had symptoms of intolerance (abdominal distention, flatulence, and diarrhea). All seven patients responded to a starch elimination diet. After reintroduction of a starch diet, diarrhea recurred in four patients; this was alleviated 48 hours after reelimination of starch. We conclude that intestinal glucoamylase deficiency is present in some patients with chronic diarrhea.
 ...
PMID:Small intestinal glucoamylase deficiency and starch malabsorption: a newly recognized alpha-glucosidase deficiency in children. 815 67