There have been several reports of the incorporation of glucosamine into liver glycogen by an intraperitoneal injection of galactosamine, but it has not previously been considered that glucosamine is a normal component of liver glycogen. We now report that glucosamine occurs endogenously in rabbit- and pig-liver glycogens in the amount of about 1 nmol per 10 mg glycogen. Like the glucosamine incorporated by exogenous administration of galactosamine, the endogenous glucosamine takes the place of 1,4-linked α-glucose residues. It is found in both the outer and inner chains of the glycogen molecule.
