Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Brush-border membranes prepared from proximal and distal human small intestine were characterized with respect to lipid fluidity, lipid composition, and protein-lipid interactions. Steady-state fluorescence polarization and differential polarized phase fluorometry revealed that the "static" and "dynamic" rotational components of fluidity (assessed by r infinity values of 1,6-diphenyl-1,3,5-hexatriene and r values of 12-anthroylstearate, respectively) were greater in the distal membranes compared with their proximal counterparts. The lipid fluidity of distal brush-border membranes was also greater as measured by excimer/monomer fluorescence ratio intensities of pyrene decanoate. A lower molar ratio of cholesterol/phospholipid in the distal membranes was responsible for these regional fluidity differences. Lipid thermotropic transitions were detected at 26-28 degrees C using 1,6-diphenyl-1,3,5-hexatriene in proximal and distal membranes. Arrhenius plots of p-nitrophenylphosphatase and gamma-glutamyl transpeptidase activities demonstrated breakpoints in the vicinity of the lipid thermotropic transition temperatures (28-30 degrees C), whereas maltase and sucrase yielded a single activity slope over the range of 10-40 degrees C. Moreover, 50 mM benzyl alcohol fluidized proximal brush-border membranes and increased p-nitrophenylphosphatase activity in this membrane. This agent also shifted the phase transition temperature of the membrane and breakpoint temperature of this enzymatic activity from approximately 28 degrees C to 19 degrees C. These findings demonstrate that differences in human small intestinal brush-border membrane lipid fluidity and lipid composition exist between proximal and distal regions of this organ. Furthermore, alterations in fluidity and/or lipid composition modulate p-nitrophenylphosphatase and gamma-glutamyl transpeptidase but not sucrase or maltase activities in these membranes.
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PMID:Protein-lipid interactions in human small intestinal brush-border membranes. 259 11

The present study was designed to evaluate the effects of three non-steroidal anti-inflammatory drugs (NSAIDs) with varying cycloxygenase selectivities on the small intestinal biochemical composition, function and histology during 1, 2-dimethylhydrazine (DMH) administration. Sprague Dawley male rats were divided into five different groups viz: Group 1 (control, vehicle treated), Group 2 (DMH-treated, 30 mg/kg body weight/week in 1 mM EDTA-saline, subcutaneously), Group 3 (DMH + aspirin-60 mg/kg body weight), Group 4 (DMH + celecoxib-6 mg/kg body weight), Group 5 (DMH + etoricoxib-0.64 mg/kg body weight). After six weeks of treatment, brush border membrane was isolated from the jejunum segment of all the groups and changes in the associated enzymes such as sucrase, lactase, maltase, alkaline phosphatase, membrane lipid composition, fluorescence polarizations of diphenylhexatriene, pyrene excimer formation, histological changes and surface characteristics were studied. The results indicated a significant alteration in the enzyme activity as well as changes in the structure and function of the intestine in the presence of the pro-carcinogen, DMH, which suggests the possible chemopreventive efficacy of NSAIDs against the intestinal cancer.
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PMID:Effect of non-steroidal anti-inflammatory drugs and the pro-carcinogen 1,2 dimethylhydrazine on the rat intestinal membrane structure and function. 1916 Aug 94