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Biomedical subjects

A Singh

Publications and source records attributed to A Singh.

At least 901 records · Page 50Linked to original sources
PubMed1973

Fat absorption in essential fatty acid deficiency: a model experimental approach to studies of the mechanism of fat malabsorption of unknown etiology.

Male rats were made deficient in essential fatty acids by feeding them a fat-free diet supplemented with 4% tripalmitin for 8-12 wk from the time of weaning. After feeding 0.5 ml of [(14)C]triolein or [(3)H]oleic acid, 72-hr stool recoveries of radioactivity were significantly greater in deficient rats than in chow-fed controls. Essential fatty acid deficiency did not reduce the absorptive capacities for triolein or for a medium-chain fat, trioctanoin, measured after 3 and 2 hr of maximal-rate duodenal infusion. In everted jejunal slices from essential fatty acid-deficient rats, uptake of micellar [(14)C]oleic acid at 0-1 degrees C was similar to that of controls, but the rate of incorporation of fatty acid into triglyceride after rewarming to 37 degrees C was significantly reduced. The specific activities of the microsomal esterifying enzymes, acyl CoA:monoglyceride acyltransferase and fatty acid CoA ligase in jejunal mucosa were 30% lower in essential fatty acid-deficient rats. However, the total microsomal enzyme activity adjusted to constant weight did not differ significantly in deficient rats compared with controls. After intraduodenal perfusion of triolein, accumulation of lipid in the intestinal wall was increased in the deficient rats. Because over 90% of the absorbed mucosal lipid was present as triglyceride, essential fatty acid deficiency appears to affect the synthesis or release of chylomicron lipid from the intestine. Analysis of regions of intestine showed that this delay in transport was most marked in the midportion of the small intestine.

Acyltransferases↗
PubMed1973

New colorimetric method for the quantitative estimation of phospholipids without acid digestion.

A unique colorimetric method for the quantitative determination of phospholipids that does not involve the acid digestion of the lipid is described. The phospholipids, after separation by thin-layer chromatography and elution from the silica gel, are heated with a chromogenic solution that is a modification of a spray reagent formulated by Vaskovsky and Kostetsky (1968, J. Lipid Res., 9: 396). The absorbance of the colored complex was read at 710 nm, and it followed Beer's law in the range of 1-10 micro g of phospholipid phosphorus.

Chromatography, Thin Layer↗