IMMUNOHISTOCHEMICAL LOCALIZATION OF L-TYPE CALCIUM CHANNELS IN THE DEVELOPING 1ST MOLAR OF THE RAT DURING ODONTOBLAST DIFFERENTIATION

To study the presence of L-type calcium channels during the different steps of odontoblast differentiation, a specific monoclonal antibody a gainst 1,4-dihydropyridine receptors was used in combination with avid in-biotin-peroxidase complex labelling. Staining was seen on the cell bodies of pre-odontoblasts, concentrated at the apical pole (distal po rtion) of functional odontoblasts and localized on cell bodies and pro cesses of mature odontoblasts. Thus calcium channels were expressed at the onset of differentiation and maintained in the differentiated cel ls but with some changes of localization. It is suggested that these c hannels may facilitate the entry of calcium to act as a second messeng er for cellular polarization or be involved in the transcellular trans port of calcium to the mineralizing front.