Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.108 (lactase)
 2,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was undertaken to investigate the effect of alcohol on the activity of jejunal disaccharidases (DS). The activity of DS in a preparation of purified brush border membrane of hamster jejunum was measured in the absence and in the presence (0.8 to 6.4% wt/vol) of ethanol. To compare the effect of alcohol on DS with its action on a brush border enzyme of a different group, we also measured the activity of alkaline phosphatase (AP) under similar conditions. Ethanol depressed the activity of sucrase, maltase, and lactase in a dose-dependent and time-dependent manner, but it stimulated the activity of AP. The ethanol-induced inhibition of DS was completely reversible. Kinetic studies indicate that ethanol depressed the Vmax and increased the Km of sucrase and lactase. The Vmax of maltase also decreased, but the Km of this hydrolase was not affected by ethanol. From the results of this study it would appear that acute exposure of the jejunal brush border to ethanol depresses the DS activity of the membrane and that (because the AP was not depressed) the ethanol-induced inhibition of DS is not the result of a general inhibition of all enzymes of the brush border.
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PMID:Effect of ethanol on disaccharidases of hamster jejunal brush border membrane. 11 61

Of 40 patients with a partial gastrectomy (Billroth-II) 10 developed a milk intolerance and 11 had a lactase deficiency, the latter in 4 cases appearing together with a decrease in other disaccharidases. Only 2 of the 11 lactase-deficient patients complained of milk intolerance. The Ethanol lactose tolerance test (ELTT) was performed in 21 patients and was found to be abnormal in 6. Whereas cases of abnormal ELTT usually (4 of 6 cases) showed a lactase deficiency, only 2 patients with milk intolerance showed an abnormal ELTT and lactase deficiency. Milk intolerance can therefore only exceptionally be explained by lactase deficiency, and lack of lactase in the upper jejunum usually does not produce intolerance symptoms. Moreover, in comparable determinations from the afferent and efferent jejunal loop no differences in enzyme activities could be observed.
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PMID:[Milk intolerance, lactose intolerance and lactase deficiency in partial resection of the stomach]. 94 55

The acute effects of intraduodenal administration of ethanol, 5 g/kg body weight, on intestinal activities of lipid-reesterifying and disaccharidase enzymes of the small bowel were studied. Results were compared to those produced in controls receiving isocaloric amounts of glucose by the same route. Acyl-CoA:monoglyceride acyltransferase, acyl-CoA synthetase (acid:CoA ligase (AMP) EC 6.2.1.3), sucrase, and lactase assays were performed on jejunal samples; acyl-CoA synthetase assay was performed on ileal samples. Ethanol produced greater activities of the lipid-reesterifying enzymes in the jejunum than did glucose. Ileal specific activity of acyl-CoA synthetase was also increased in the experimental group. No effect of ethanol on jejunal disaccharidase enzyme activities was noted. It is concluded that ethanol given acutely has a specific stimulating effect on intestinal enzymes involved in lipid absorption.
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PMID:The effect of acute ethanol treatment on lipid-reesterifying enzymes of the rat small bowel. 116 87

1. The metabolic consequences of chronic ethanol feeding was investigated by assay of urinary metabolites. Male Wistar rats were fed a liquid diet containing 35% of total energy as ethanol or isovolumetric, isocaloric and isonitrogenous amounts of the same diet in which ethanol was substituted by isocaloric glucose (controls). 2. At 6 weeks the entire skeletal muscle mass was reduced by approximately 20%. The urinary excretion of nitrogen, urea and uric acid increased by between 23 and 128%. Urinary creatinine excretion was not significantly altered. 3. Urinary excretion of magnesium was significantly increased by 43%. Urinary excretion of sodium, potassium, calcium and phosphate was increased slightly (i.e. 5-22%), but this change was not statistically significant. 4. Proton n.m.r. spectroscopic analysis showed that ethanol feeding reduced the urinary excretion of citrate and 2-oxoglutarate (by approximately 50%), suggesting decreased citric acid cycle activity. There was an increased excretion of alanine (44%), but excretion of succinate and acetate was not significantly altered. Ethanol in the urine of ethanol-fed rats comprised approximately 2% of total ethanol intake and less than 1% of total energy intake. 5. Lactose was detectable in urine of ethanol-fed rats, but not in control rats, reflecting the reported decreased intestinal lactase activity and increased gut permeability in alcoholics. Urinary galactose excretion decreased by 41%, but relatively large increases in lactate excretion (50%) did not achieve statistical significance. 6. It was concluded that chronic ethanol feeding causes disturbances in whole-body nitrogen homoeostasis and alterations in intermediary metabolism.
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PMID:Urinary excretion of nitrogenous and non-nitrogenous compounds in the chronic ethanol-fed rat. 185 Oct 76

Ethanol consumption has a toxic effect on the epithelium of the small bowel, but enterocyte maturity is very difficult to measure under these circumstances. However, when ethanol intake is combined with enterectomy, enterocyte immaturity is greater, permitting an easier separation of these two effects. In a group of rats (13 male Wistar rats weighing approximately 220 g) fed a liquid diet containing 35% ethanol for 4 weeks after resection of the proximal jejunum, the residual small intestine brush border maltase, sucrase, and lactase activities were similar to those of a pair-fed control group (13 animals). However, alkaline phosphatase activity was decreased in the mucosa and in the enterocyte brush border, probably because of the lower activity of this enzyme in the jejunum-ileum remnant of the alcoholic group.
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PMID:Effect of chronic ethanol consumption on the activities of residual small bowel brush-border enzymes after proximal jejunum resection in the rat. 865 45