Ultrastructural changes of secreting rat-incisor ameloblasts following administration of vincristine and vinblastine.

Ultrastructural changes of secreting rat-incisor ameloblasts after administration of vincristine and vinblastine were observed. Polarity of nuclei and cytoplasmic organellae was remarkably disturbed; consequently, the regular secreting orientation of cellular products was altered greatly, leading to heterotopic deposition of large amounts of enamel matrix.