Glycogen Synthesis from Pyruvate in Muscle

Abstract

UNDER normal conditions glucose is the major source of muscle glycogen. In muscle, pyruvate and lactate make only a minimal contribution to glycogen but the liver can freely convert these compounds into glycogen^1,2. One of the key enzymes in the process of glycogenesis in liver is fructose-l,6-diphosphatase (FDPase)³, and the inability of muscle to convert pyruvate to glycogen was attributed to its absence^4,5. Recently, however, Krebs and Wood-ford6 have shown that the enzyme does occur in striated muscle, so that at least one of the energy barriers in the conversion of pyruvate to glycogen is now known to be surmountable.