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Biomedical subjects

G R Thompson

Publications and source records attributed to G R Thompson.

At least 235 records · Page 13Linked to original sources
PubMed1971

Action of neomycin on the intraluminal phase of lipid absorption.

Administration of a single 1 g dose of neomycin sulfate to five healthy subjects simultaneously with a test meal caused a marked increase in the proportion of fatty acid and bile acid in the ultracentrifuged deposit of aspirated intestinal contents. Labeled cholesterol was precipitated in a similar manner in two hypercholesterolemic patients. Neomycin had no effect on the pancreatic lipase concentration or on the pH of intestinal contents. These results confirm that the ability of neomycin to precipitate micellar lipids is due to interaction between the polybasic neomycin molecule and ionized fatty acids and bile acids. This mechanism provides an explanation for both the steatorrhea and hypocholesterolemia induced by this compound.

Administration, Oral↗
PubMed1969

Effect of cholestyramine on the absorption of vitamin D3 and calcium.

The absorption of 10 mug doses of vitamin D(3)-(3)H in rats was found to be decreased by the addition of cholestyramine to the diet in an amount sufficient to cause steatorrhoea. Studies in vitro suggested that the effect of cholestyramine was due to its known ability to bind bile salts and thus disrupt micelles containing vitamin D. The absorption of 1 mg (47)calcium chloride was similar in both control and cholestyramine-fed rats, whether estimated by the whole body counting or the faecal excretion technique. These findings show that the administration of cholestyramine causes a reduction in the absorption of vitamin D(3)-(3)H but not of radiocalcium.

Animals↗
PubMed1969

Effect of mixed micellar lipid on the absorption of cholesterol and vitamin D3 into lymph.

The absorption of endogenous cholesterol, labeled with tracer doses of cholesterol (14)C or cholesterol-(3)H and of near physiological doses of vitamin D(3)-(3)H was studied in rats with cannulated intestinal lymphatics. The effects of administering mixed micellar solutions of fatty acid, monoglyceride, and bile salt on the absorption of these labeled sterols was determined. It was observed that the specific activity of free cholesterol and the amounts of vitamin D(3) appearing in lymph were significantly increased during the intraduodenal administration of mixed micellar solutions of either linoleic or palmitic acid, in contrast to control rats receiving a micellar solution of taurocholate. These increases were related linearly to the lymph triglyceride level. In addition it was observed that when the linoleic acid solution was administered there was a more marked increase in the ratio of the specific activities of free and esterified cholesterol in lymph than with either the palmitic acid or taurocholate solutions. Additional studies in rats with intact lymphatics showed that the uptake of labeled cholesterol and vitamin D(3) from the intestinal lumen into the wall was similar whether the sterols were administered in taurocholate or in mixed micellar solution. These findings suggest that mixed micellar lipid increased the rate of appearance of labeled free cholesterol and vitamin D(3) in lymph by enhancing their transport out of the intestinal mucosa, rather than by an effect on uptake.

Animals↗