EFFECTS OF KETOHEXOSEMIA ON THE KETOHEXOSE TRANSPORT IN THE SMALL-INTESTINE OF RATS

It was previously observed that sustained hyperglycemia enhances the intestinal transport of aldohexoses; on the other hand, hyperfructosemia primarily affects the transport of fructose. The hyperketosemia-induced intestinal ketose transport is examined in detail. I.v. infused 3-O-methylfructose produces marked 3-O-methylfructosemia without concomitant hyperglycemia; in such animals the intestinal transport of both fructose and 3-O-methylfructose increased. The hyperketosemia-induced increased ketose transport was inhibited by phloretin, but only if placed on the serosal compartment. Phlorizin affects neither the basal nor the induced intestinal ketohexose transport. The enhancement of the intestinal ketohexose transport is not Na-dependent and is not inhibited by ouabain.