<ORIGINAL ARTICLE>Histochemical Localization of Carbonic Anhydrase in the Taste Buds of the Mouse and Goldfish

Abstract

The activity of carbonic anhydrase in the taste buds of the mouse and goldfish was examined by enzyme histochemistry. An intense reaction of carbonic anhydrase was observed in the middle and basal regions of the taste buds in the mouse circumvallate papillae. Under the electron microscope, the reaction product was found in the cytoplasm of type-I cells which are characterized by the presence of ribosomes and rough endoplasmic reticulum. In other cell types (type-II and type-Ill cells), no reaction was detected. In the fungiform papillae, the reactivity was similar to that in the circumvallate ones; however, only a few cells were positively stained. In the goldfish, the receptor cells, which are characterized by the presence of tubular system, showed strong carbonic anhydrase activity. The results suggest that the activity of carbonic anhydrase, which is usually associated with H^+ or HCOs transport, is present in a specific type of taste bud cells