Glycoconjugate in rat taste buds

The taste buds of the fungiform papillae, circumvallate papilla, foliate pa pillae, soft palate and epiglottis of the rat oral cavity were examined by lectin histochemistry to elucidate the relationships between expression of glycoconjugates and innervation. Seven out of 21 lectins showed moderate to intense staining in at least more than one taste bud. They were succinylat ed wheat germ agglutinin (s-WGA), Dolichos biflorus agglutinin (DBA), Bande iraea simplicifolia lectin-I (BSL-I), Ricinus communis agglutinin-I (RCA-I) , peanut agglutinin (PNA), Ulex europaeus agglutinin-I (UEA-I) and Phaseolu s vulgaris agglutinin-I (PHA-L). UEA-I and BSL-I showed moderate to intense staining in all of the taste buds examined. They strongly stained the tast e buds of the epiglottis, which are innervated by the cranial nerve X. UEA- I intensely stained the taste buds of the fungiform papillae and soft palat e, both of which are innervated by the cranial nerve VII. The taste buds of circumvallate papilla and foliate papillae were innervated by the cranial nerve IX and strongly stained by BSL-I. Thus, UEA-I and BSL-I binding glyco conjugates, probably a-linked fucose and a-D-galactose, respectively, might be specific for taste buds. Although the expression of these glycoconjugat es would be related to the innervation of the cranial nerve X, the differen tial expression of a-linked fucose and a-D-galactose might be related to th e innervation of the cranial nerve VII and IX, respectively.