Occurrence of gustducin-immunoreactive cells in von Ebner's glands of guinea pigs.

An immunohistochemical examination of guinea-pig taste buds in vallate papillae revealed gustducin-immunoreactive cells in the area of von Ebner's glands, minor salivary glands. Since there have been no reports describing those cells in these locations for other species, we investigated these glands in order both to localize the cells and compare their immunoreactive characteristics with corresponding cells in the vallate taste buds. The gustducin-immunoreactive cells coincided with cells containing no secretory granules in the end portion of the glands, which was supported by the electron-microscopic immunocytochemistry. Double immunofluorescence microscopy confirmed these cells to be entirely immunopositive to type III inositol 1,4,5-triphosphate receptor (IP3R-3), phospholipase Cβ2 (PLCβ2), and villin and also partly immunopositive to neuron-specific enolase (NSE) and calbindin D-28K. The gustducin-immunoreactive cells in the vallate taste buds exhibited completely the same immunoreactivities for these five molecules. Accordingly, the present results give credence to a consideration that the gustducin-immunnoreactive cells in both locations are identical in function(s) e.g., chemo-reception.