1996 Volume 21 Issue 3 Pages 205-214
The localization of Na/K-ATPase in the mouse molar enamel organs and the subunit constitution of the enzyme were investigated by means of enzyme histochemistry and immunohistochemistry, using ahtibodies for the α and β subunits of the anti-rat Na/K-ATPase. Intense enzyme reaction of ouabain-sensitive p-nitrophenylphosphatase was specifically localized on the stratum intermedium. Among five different anti-subunits of Na/K-ATPase, only α2 and β1 subunits were immunohistochemically localized on the stratum intermedium. When the chronological change in the localization of Na/K-ATPase during tooth development was immunohistochemically assessed using anti-β1 subunit, the area of positive reaction in stratum intermedium moved from the cuspal region to the cervical region as the enamel matured. After the completion of the enamel matrix maturation, the immunoreaction for the anti-β1 subunit disappeared from the enamel organ. These results indicate that Na/K-ATPase in the stratum intermedium is composed of α2 and β1 subunits, and that the enzyme is significantly involved in the enamei maturation.
