Ultrastructural study of the protein-polysaccharides distribution in enamel from rat incisors.

The distribution pattern of the protein-polysaccharides in the rat incisor enamel was similar whether stained for glycoproteins (phosphotungstic acid) or for proteoglycans (alcian blue, bismith nitrate). Except for the holes at the dentino-enamel junction, where these components seem to exist as amorphous gel, protein-polysaccharides are closely associated to the proteinic fibrous matrix in rods and interrods structures as in prism sheaths where they are particularly abundant.