A radioautographic study of the effects of vinblastine on the fate of injected 45calcium and [125I]-insulin in the rat incisor.

To examine the effect of vinblastine on the movement of calcium and macromolecules through the enamel organ in the secretion zone and through the odontoblast layer, 45CaCl2 and [125I]-insulin were used as radioautographic tracers. Vinblastine did not alter the localization of either labelled Ca or insulin in the enamel organ and underlying enamel, but eliminated both labels in the pulp, odontoblasts and dentine. It is concluded that vinblastine has no effect on the passage of Ca and macromolecules in the enamel organ and secretory ameloblast layers, whereas its effect on the pulp and odontoblasts prevents passage of these tracers into the predentine and dentine.