Conversion of glucose to glycogen after ingestion of a high-carbohydrate diet

¹ Department of Poultry Husbandry and the Donner Laboratory, University of California, Berkeley, California

The glycogen content of nine tissues of trained-fed rats was investigated at fasting and at different times after eating with and without water. With the exception of the brain and muscles, the tissues contained little or no glycogen at fasting and accumulated variable amounts during the course of digestion with peak accumulation in most cases 4–7 hours after the commencement of feeding. The brain glycogen did not vary in the rats in spite of the different experimental conditions of this study. The amount of muscle glycogen in the fed rats was the same or slightly more than the amount found in the fasting rats. The fasting liver incorporated C¹⁴ substrates into glycogen while it was decreasing in amounts. Fasting muscles incorporated C¹⁴ substrates almost as fast as fed muscles indicating that muscle glycogen behaved as an intermediate compound and was metabolized as fast as formed. Accumulation of glycogen in the mesenteric, renal and subcutaneous fatty tissues was decreased by a) feeding without water and b) excessive deposits of fat in the fatty tissues.