Efficient hepatic glycogen synthesis in refeeding rats requires continued carbon flow through the gluconeogenic pathway.

Intragastric infusion of [1-14C]glucose into awake, fasted rats at rates that produced physiological increases in the circulating glucose concentration resulted in active glycogen deposition in liver. However, degradation of this glycogen revealed extensive randomization of the label among the carbon atoms of glucose. By contrast, muscle glycogen-glucose was labeled primarily in C-1. Treatment of…