A common pathway for sugar transport in hamster intestine

Abstract

The competition between different sugars for the transport mechanism of hamster small intestine was tested with an in vitro method which allowed the use of a single segment of intestine for both control and experimental periods. The transport of the test sugar d-galactose was inhibited by other sugars known to be actively absorbed by the intestine; namely, d-glucose, α-methyl-d-glucoside, i-deoxy-d-glucose, 6-deoxy-d-glucose and 3-o-methyl-d-glucose. On the other hand d-mannose and d-xylose, two sugars not actively transported, did not inhibit d-galactose absorption. In addition, sugars known to be actively absorbed produced an inhibition of transport of d-glucose and 6-deoxy-d-glucose when these were selected as test sugars. The results of these experiments are consistent with the view that all transported sugars compete for a common pathway in hamster intestine. Various hypotheses of sugar transport are discussed in light of the present data.