Mechanism studies of glycogen and glyceride glycerol biosynthesis.

It is well known that isotopic tracer st,udies of a complex system of interrelated reactions can determine the existence and magnitude of reaction sequences for transferring atoms from a given reactant to a particular product and also in many cases, usually through studies involving asymmetrically labeled reactants and including degradation of the products, establish parameters with which postulated mechanisms for the sequences must concur. Such studies have been reported for the system of interrelated reactions yielding liver glycogen; various non-uniformly labeled acetates, propionates, butyrates, lactates, and pyruvates (l-4) and valerate-1-C’3-4-C14 have been used as reactants (5). We have observed the appearance in liver glycogen and carcass glyceride glycerol of Cl4 administered intraperitoneally to normal, intact, male albino rats as glyceroll-Cl4 (6) and are now reporting degradation studies establishing the Cl4 distribution within those molecules.