CYTOCHEMICAL-LOCALIZATION OF GUANYLYL CYCLASE ACTIVITY IN RABBIT TASTE BUD CELLS

Guanylyl cyclase activity was cytochemically demonstrated in rabbit foliate taste buds. The enzymatic activity was localized in the apical portion (microvilli and neck) of taste bud cells. Especially strong activity was observed on the microvillous membrane of type I (dark) cells and often on a blunt process of type III cells. The microvilli of type II (light) cells showed weak enzymatic activity. Considering that the apical portion of taste cells is a likely site of interaction between taste stimuli and the cells, the results support the idea that cyclic GMP is involved in taste transduction.