Some Experiences with Labeling Sugars by Tritium Gas Exposure

Abstract

Our interest in the Wilzbach direct tritium-labeling procedure [1] was aroused by the possibilities it offered to obtain radioactive counterparts of sugars and sugar analogs for which chemical synthesis from C¹⁴-labeled precursors is either very difficult, prohibitively expensive, or both. With few exceptions, it seems, only naturally occurring hexoses are easily labeled with C¹⁴, inasmuch as biosynthetic methods may be used. In our older studies with animal tissue hexokinase [2], and in our more recent studies of various aspects of membrane transport of sugars in ascites tumor cells [3], kidney cortex slices [4] and intestinal epithelial cells [5, 6] we have found particularly useful a group of compounds which are analogs of D-glucose but which, unlike glucose, cannot be metabolized by animal tissues. It is this very property, metabolic inertness, so useful to us on the one hand, that is, on the other hand, an effective barrier to easy C¹⁴-labeling of these compounds.

Presented at the Fourth Symposium on Advances in Tracer Methodology, 1960.