Inhibition of Intestinal Amino-acid Transport by Sugars

Abstract

GALACTOSAEMIA, an inborn defect of galactoso metabolism, is known to be associated with derangements in the renal tubular transport of amino-acids¹. It is of interest that some of the features of this disease, including amino-aciduria, can be reproduced in rats by feeding them a diet containing 30 per cent galactose². Recently, Segal et al.³ have shown that the uptake of certain amino-acids by rat kidney slices can be inhibited in vitro by galactose and fructose at relatively low concentrations (5.6 m molar), while at a higher concentration (16.8 m molar) glucose also exerts some inhibitory effect. Since in the mammalian organism many of the transport processes of the kidney and the small intestine appear to be similar we have examined the effect of sugars, especially galactose, on the transport of amino-acids by the small intestine of the rat.