A radioautographic study of the distribution of labelled sugars in rat tissues

In various experiments, young rats were given single injections of labelled sugars, particularly 3H-1-galactose and 3 H-1-mannose, and sacrificed after various time intervals. Radioautographs showed that 3H-1-galactose and 3H-1-mannose were incorporated into a great variety of cells. Most mucous cells showed heavy reactions; label appeared first in the Golgi region, later in mucus. In reactions over chondrocytes, label appeared to migrate from Golgi region to surrounding matrix. Many cells utilized 3H-1-galactose and 3H-1-mannose to a different extent. After 3 H-1-galactose only, heavy reactions appeared over certain nonsecretory cells (duodenal columnar, various duct cells) in which label appeared to migrate to cell coat. Argentaffin and osteoclast cells showed intense, diffuse, cytoplasmic reactions, but only after 3H-1-mannose; no migration of label appeared within five hours. Amylase treatment reduced reaction over certain cells, indicating that some label was incorporated into glycogen. In conclusion, 3H-1-galactose and 3H-1-mannose incorporation, for synthesis of glycogen and presumably other complex carbohydrates, is widespread