Induction of apoptosis by colchicine in taste bud and epithelial cells of the mouse circumvallate papillae

Apoptotic cells in the taste buds and epithelia of mouse circumvallate papi llae after colchicine treatment were examined by the methods of in situ DNA nick-end labeling, immunocytochemistry, and electron microscopy. After col chicine treatment, numerous positive cells appeared in the taste buds by DN A nick-end labeling, and some epithelial cells in the basal and suprabasal layers in and around the circumvallate papillae also revealed positive stai ning. Condensed and fragmented nuclei with a high density were occasionally found in the taste bud cells and in the basal and suprabasal layer epithel ial cells by electron-microscopic observation. An immunocytochemical reacti on for tubulin revealed weak staining in taste bud cells, because of the de polymerization of microtubules, and a decrease of the microtubules in the t aste bud cells was observed by electron microscopy. These results indicate that colchicine treatment of mice induces the apoptosis of taste bud and ep ithelial cells in the circumvallate papillae and dorsal epithelial cells ar ound the circumvallate papillae.