Ruffle-ended maturation ameloblasts in the pigmentation zone of rat incisor

Rats were perfused with glutaraldehyde and the incisors were dissected free. Midsagittal slice of the incisor were demineralized and the pigmented zone were further sliced into thin cross sections. The lysosomal activity was demonstrated utilizing CMPase. Two patterns of localization were observed. Weak local reaction product associated with the pigment granules. The second one was intense reaction product with some of the ruffled border of ameloblasts. A suggested role for these localizations were discussed in relation to pigment release into the enamel surface.