Radioautographic analysis of ³H‐fucose utilization by fibroblasts of the periodontal ligament

The secretion of ³labeld glycoproteins from periodontal ligament fibroblasts was, studied by light and electron microseopic radioautography. At 5, 10. and 20 minutes after intravenous injection, ³H‐fucose was concentrated in Golgi cisternae and saccules. By 35 minutes, the label was dispersed to the cell periphery and extracellular matrix. At 8 hours after injection, almost all of the radioactive label was associated with the cell surface or the adjacent extracellular matrix. Labeled glycoprotein was contained in collagen secretion granules and appeared to be relesasd simultaneousley with the collagen precursors The distribution of ³H‐fucose labeled material was uniform across the periodontal ligament.