Evidence for the presence of glycogen in rat thymus.

Chemical and biochemical analysis of the polysaccharide, present in rat thymus, indicate that it consists of glucose units alpha-1,4 and alpha-1,6 linked. Electron microscopy reveals the presence of a polysaccharide, similar to the beta-glycogen particles observed in liver and muscle with an average diameter of 20-30 nm. They are located in the cytoplasmic area of T-cells from the cortical region of the thymus. Enzymatic analysis indicates that the beta-particles contain a highly branched glucan with short external chains. Some of the enzymes of glycogen metabolism: synthase, phosphorylase and branching were for the first time partially purified from rat thymus and some of their properties were studied. Therefore, glycogen appeared to be synthesized in rat thymus.