Intestinal absorption of sucrose in man: interrelation of hydrolysis and monosaccharide product absorption.

Open Access
Publisher Website
Google Scholar
Abstract
Sucrose absorption was studied in man and expressed in terms of sucrose hydrolysis and absorption of its component monosaccharides, glucose and fructose. Sucrose hydrolysis rates exceeded the monosaccharide product absorption rates, and the glucose component was absorbed considerably more rapidly than the fructose component. Moreover, paired experiments demonstrated the same absorption rates of these monosaccharides from sucrose as from an equivalent glucose-fructose mixture. Hence, hydrolysis does not appear to be rate limiting in the process of sucrose absorption, and the individual absorption rates for glucose and fructose may define the rate of the disaccharide absorption process. Comparison of absorption from solutions having different concentrations of sucrose showed the kinetic relationships to be variable from subject to subject, but Lineweaver-Burk plots revealed saturation kinetics that were nearly identical for sucrose hydrolysis and glucose product absorption, suggesting an interdependence of these 2 processes. The addition of galactose to the sucrose solution infused caused an appreciable decrease in sucrose hydrolysis and glucose product absorption, but had no effect on fructose product absorption. Since galactose is known to compete , with glucose for the active transport process, this suggests that intestinal sucrase is inhibited either by the glucose product or by a feedback inhibition by a saturated active transport mechanism.

This publication has 35 references indexed in Scilit: