The phosphorylation and absorption of sugars in the rat. 2. Sugar absorption in vivo, and its relationship to the phosphorylation of sugar in vitro

Abstract

The stock of rats used in the expts. on the hexokinase reaction in vitro show the same behavior regarding absorption of sugar in vivo as do rats used in expts. upon absorption descr. in the literature. The phos-phorylation-rate ratios for sugars investigated are very similar to their absorption rate ratios. The rate of the hexokinase reaction catalyzed by the intestinal mucosa is more than sufficient to account for the phosphorylation of all the sugar absorbed during the expts. in vivo. It is sufficient to account for the phosphorylation of at least 50% of the carbohydrate consumed by a normal 150 g. rat during 24 hrs., and for the phosphorylation of 70-100% of this carbohydrate after certain legitimate corrections were applied to the figures for the hexokinase reaction.