AUTORADIOGRAPHIC DETECTION OF RADIOSULFATE INCORPORATION BY THE GROWING ENAMEL OF RATS AND HAMSTERS

¹ Department of Histology and Embryology, University of Ottawa, Ottawa, Ontario

Radiosulfate administered subcutaneously to young rats and hamsters has been detected autoradiographically in the ameloblasts and new enamel during the period of growth. It seems to be synthetized into an acid sulfomucoprotein which appears in the matrix before keratin and disappears progressively.

This substance is acid fast and hyaluronidase resistant. When present in large amounts, it may be an inhibitor of mineralization. Its formation and secretion are concomitant with alkaline phosphatase activity.

During the maturation period of the enamel, a concentration of S³⁵ appears at the dentinoenamel junction and diffuses upward. It is probably coming from the dentin, and it might represent an invasion of sulfopolysaccharides favoring mineralization.