HISTOCHEMICAL OBSERVATION ON PHOSPHATASE ACTIVITIES OF DIFFERENTIATING TASTE BUD

Adenosine triphosphatase, alkaline phosphatase and acid phosphatase activities of the developing taste buds were observed histochemically in the rat circumvallate papilla. Adenosine triphosphatase activity was already demonstrable in a cluster of cells in the epithelium of the papilla on the first day of birth, when taste buds could not yet be morphologically identified. The cells with the activity are certainly considered as the differentiating taste bud cells. These cells took the form of a bud similar to the adult one about the fourth day of life. Alkaline phosphatase activity was demonstrated first on the superficial cell layers of the epithelium of its apical surface as well as on that of the epithelium in the gutter of circumvallate papilla just after birth. The activity in the gutter then rapidly increased, while the activity of the apical surface abruptly decreased and disappeared on the second day of life. Acid phosphatase was demonstrable only in some cells of the taste bud on the fourth day of life. The final pattern of the activity, which is found in the supranuclear cytoplasm of taste bud cells, was established after the eighth day of life. Copyright © 1969 Wiley‐Liss, Inc.