Incorporation of 3H-fucose label into glycoprotein in the golgi apparatus of rat cells, and its passage to the cell coat and to lysosomes.

Young rats were injected with 3H-fucose and sacrificed after various times. In electron microscopic radioautographs of duodenal villus columnar cells and hepatocyes, at 2 minutes after injection the label was localized mostly over the Golgi apparatus. By 20 minutes, label appeared at all cell surfaces and in lysosomes. It is interpreted that the fucose label was incorporated by the Golgi apparatus into glycoproteins which migrated to lysosomes and to all cell surfaces to be added to the cell coat. A method developed to stain radioautographs of duodenal cells with phosphotungstic acid revealed glycoprotein in all labelled structures, including cytoplasmic vesicles which may transport the labelled glycoprotein to the cell surfaces. In light microscopic radioautographs of many other cell types, label appeared first over the Golgi region and later over cell secretions or over cell surfaces. Thus cell coat synthesis in all cells may be completed in the Golgi apparatus