IDENTIFICATION OF 3 PHOSPHOLIPASE-C ISOTYPES EXPRESSED IN RAT OLFACTORY EPITHELIUM

THE expression of three phosphoinositide-specific phospholipase C (PLC ) isotypes in rat olfactory epithelium was investigated using monoclon al antibodies. In intact animals, PLC beta 1 was not expressed in the olfactory epithelium but was found in glands below the epithelium. How ever, following unilateral olfactory bulbectomy (OBX), PLC beta 1 was expressed in the dendrites of some olfactory receptor neurons, primari ly in the endoturbinates on the unoperated side. PLC gamma 1 immunorea ctivity was found in the apices of sustentacular cells and in glands b elow the epithelium. PLC delta 1 immunoreactivity was found in the gla nds and in the perinuclear region and dendrites of some receptor neuro ns. Since none of the PLC isotypes studied were expressed in the cilia of receptor neurons, the results suggest that another PLC isotype is likely to be involved in mediating olfactory transduction.