Action of Insulin on Transfer of Sugars Across Cell Barriers: Common Chemical Configuration of Substances Responsive to Action of the Hormone

Abstract

It had been previously demonstrated in the authors'' laboratory that the distr. of D-galactose is affected by insulin. Under the influence of the hormone the sugar enters the intracellular compartment more readily and is finally distributed in total body water. The exptl. conditions were such (evisceration and nephrec-tomy) that galactose was not metabolically utilized. In the present work, it was shown that D-xylose and L-arabinose behave in exactly the same way as galactose. On the other hand, D-arabinose, L-rhamnose, and D-sorbitol (which are nonutilizable) and D-mannose, D-fructose, L-sorbose (which are utilized) are not affected by the admn. of insulin in this manner. It appears from the present data that only the sugars possessing the same configuration as D-glucose at carbons 1,2 and 3 are aided by insulin to enter certain cells. These considerations strengthen the postulate that the physiological action of insulin is to facilitate the transfer of glucose, as a free hexose, from the extracellular fluid to the intracellular space in certain organs and tissues.