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Biomedical subjects

S Reiser

Publications and source records attributed to S Reiser.

At least 91 records · Page 5Linked to original sources
PubMed1977

Stimulation of neutral amino acid transport by fructose in epithelial cells isolated from rat intestine.

Interest in the nutritional and physiological implications of the high dietary intakes of fructose from sucrose and isomerized corn sweeteners has directed attention to the specific metabolic properties of this monosaccharide. Epithelial cells isolated from the small intestine of Wistar rats fed a stock diet showed 24% to 57% higher transport of 1 mM leucine, isoleucine, valine, alanine, phenylalanine tryptophan and histidine in the presence of 10 mM fructose than in its absence. In contrast, 10mM glucose generally inhibited the transport of these amino acids and 10mM sorbose had no effect on leucine transport. Fructose failed to consistently stimulate the transport of basic amino acids and generally inhibited the transport of glucose and galactose, indicating that the stimulation was relatively specific for neutral amino acids. Cells preloaded with fructose optimally stimulated leucine transport in the absence of extracellular fructose. Ouabain and dinitrophenol inhibited the stimulation of leucine transport by intracellular fructose after 2 minutes. A stimulation mediated by an exchange transport mechanism was rejected on the basis of the failure of 1 mM neutral amino acids either to inhibit the transport of 10 mM fructose or to accelerate the movement of fructose out of fructose-loaded cells. Although the mechanism remains unknown, these results demonstrate a specific effect of fructose at the intestinal level that produces a stimulation of neutral amino acid transport.

Amino Acids↗
PubMed1975

Effects of sucrose feeding on the intestinal transport of sugars in two strains of rats.

The rates of intestinal transport of dietary monosaccharides and disaccharides were determined in Wistar rats and the carbohydrate-sensitive BHE rats fed either a stock diet or a 65% sucrose diet. Sucrose-fed rats of both strains generally showed large and significant increases in the rates of glucose, alpha-methylglucose, fructose, and sucrose transport. The transport of galactose, maltose, and lactose did not show consistent increases due to sucrose feeding. Although the magnitude of the increases in sugar transport due to sucrose feeding was only slightly greater in BHE rats than in Wistar rats, BHE rats tended to exhibit a greater rate of sugar trnasport when fed both strains and in the BHE rats fed the stock diet. Lipogenic enzyme activity was greatly increased as a result of sucrose feeding; however, BHE rats did not show greater levels of enzyme activity than did Wistar rats. Liver lipids were increased in both the Wistar and the BHE sucrose-fed rats and in BHE rats fed either diet.

Animal Nutritional Physiological Phenomena↗
PubMed1975

Effects of sugars on leucine and lysine uptake by intestinal cells from rats fed sucrose and stock diets.

The effect of various dietary sugars on the uptake of 1 mM leucine and 1 mM lysine by intestinal cells isolated from stock-fed and sucrose-fed rats was determined. Leucine uptake was activated by 10 mM fructose and inhibited by 10 mM glucose or 20 mM sucrose on both diets. The major dietary effect noted was a significant increase in the inhibition of leucine by glucose in the sucrose-fed rats. The uptake of lysine was minimally affected by the sugars irrespective of the diet fed. These results demonstrate an important dichotomy in the properties of glucose and fructose transport in the intestine and suggest that dietary fructose may increase the transport of certain amino acids.

Animals↗