Localisation of P-2x receptors in human salivary gland epithelial cells and human embryonic kidney cells by sodium dodecyl sulfate-polyacrylamide gelelectrophoresis/Western blotting and immunofluorescence

Human salivary gland epithelial cells, a continuous cell line derived from an irradiated human salivary gland and human embryonic kidney cell line hum an embryonic kidney (HEK)293 were examined for the purpose of establishing whether they expressed endogenous P-2X ionotropic receptors at any stage in their cycles. HSG cells were found to express P2X1-6 subtypes using both W estern blotting and immunofluorescence labeling. HEK293 cells had no detect able levels of P2X1-3 and P-2X6 under normal circumstances along with very low levels of P-2X4 and P-2X5 but when the cells were grown past confluence then all subtypes were expressed on the surface membrane with the exceptio n of P-2X2. The results are discussed in terms of the likely influence of A TP acting as an intercellular signaling molecule.