Sodium Activation of Intestinal Sugar and Amino Acid Transport: A General or an Individual Effect?

Abstract

In the course of a more comprehensive study of the kinetics of sugar transport in guinea-pig small intestine, it was found that changing the ratio of the monovalent cations, sodium and potassium, had qualitatively different kinetic effects on the transport of the two isomers, α- and β-methylglucopyranoside. Such result seems to shed a new light on the interactions between sugar and amino acid transport systems in the small intestine, and particularly on the problem of whether the sodium-binding sites involved in the activation of sugar transport are the same as those involved in amino acid transport activation.