[Immunohistochemical localization of enamelin in developing rat tooth germ].

OBJECTIVE:To observe the immunohistochemical localization of enamelin in enamel formationand mineralization. METHODS:Tissue sections of the first mandibular molar tooth germ from 1, 3, 7, 10, 14 days rats after birth were prepared, expression of the enamelin protein was identified by immunohistochemical technique. RESULTS:Enamelin was found in the cytoplasm of ameloblasts in 1-10 days old rat postnatal first mandibular molar tooth germs. Enamelin appeared weakly in the tooth germs of 1 day rats. From 3 to 10 days, enamelin localized both in the cytoplasm of ameloblasts and the uncalcified enamel from the dentino-enamel junction to surfaces of the tooth. Enamelin protein was negative in the tooth germs of 14 days rats postnatally. CONCLUSION:Enamelin protein is synthesised and secreted by ameloblasts, specially localized in enamel from DEJ to surfaces of the tooth, suggesting that enamelin has important roles in enamel formation.