THE DIGESTION AND ABSORPTION OF MALTOSE AND TREHALOSE BY THE INTACT RAT.

Abstract

AbstractThe rates and sites of absorption of equal amounts of maltose and trehalose were studied and compared with those of their component monosaccharide, glucose. Using polyethylene glycol as a water‐soluble nonabsorbable marker, the transits through the gastrointestinal tract and the absorption indices for the sugars in the various segments were calculated. The rates and sites of absorption of the disaccharides were also compared with the amounts and localizations of the corresponding disaccharidases in the intestinal wall. The rates and loci of maltose and glucose absorption were the same. The rate of the intracellular hydrolysis of maltose was not rate‐limiting for its absorption. The rate of trehalose absorption during the first 2 hr after administration was not significantly different from that of glucose. During the later phase of trehalose absorption, when the remaining trehalose was in the lower small intestine and colon, this sugar was absorbed considerably more slowly. This suggests that the relative lack of trehalase in the lower small intestinal mucosa limited the rate of absorption of trehalose at this site. A considerable amount of trehalose was absorbed from the lower third of the small intestine and the colon, in contrast to glucose and maltose.