differential localization of calmodulin the 67kda calcimedin and calpactin ii in secretory ameloblasts by using specific antibodies we have shown by western blots that dental tissues contain calmodulin the 67 kda calcimedin and calpactin ii moreover by immunogold electron microscopy we were able to compare the intracellular distribution of these three calciumbinding proteins in secretory ameloblasts they were all found in the cytosol of these cells but only calcimedin was detected in the mitochondria calpactin ii was the only one present in secretory vesicles twice as much calmodulin and calpactin ii were detected in cell bodies as in tomes processes but calcimedin was more abundant in the latter the presence of these calcium mediators in well defined areas of ameloblasts may indicate differential ways for these cells to regulate different calciumdependent processes during enamel formation