Ultrastructural localization of adenosine triphosphatase in the stellate reticulum, stratum intermedium and ameloblasts of the mouse molar.

ATPase activity in the developing first mandibular molar of the mouse was demonstrated at the electron microscopic level with the method of Wachstein & Meisel (1957). It was localized along the cell surfaces of the ameloblast and stratum intermedium interface, the stratum intermedium and the stellate reticulum. The ATPase final reaction product was also present at the cell membranes of the proximal region of adjacent ameloblasts and extended to the level of the nuclei. The demonstration of ATPase mainly on the plasma membranes was similar to the observations by other investigators of various non-odontogenic cell types involved in the exchange of materials across plasma membranes.