Cloning, tissue distribution and functional characterization of the chicken P2X1 receptor

We describe a new chicken P2X subunit that is an orthologue of the mammalian P2X(1) receptor. Functional characterization of chicken P2X(1) receptors was performed using the amphotericin B perforated patch configuration to avoid the current run-down observed under whole-cell patch-clamp conditions. Responses to agonists and to the antagonist PPADS (pyridoxal 5-phosphate 6-azophenyl-2',4'-disulfonic acid) were similar to what has been described for mammalian orthologues. However, the antagonists suramin and NF023 were much less potent at chicken P2X(1) receptors than at human P2X(1) receptors. In embryonic tissues, transcript expression is predominant in lung, liver and skeletal muscle. Overlapping expression with cP2X(4) and cP2X(5) subunits in several embryonic tissues, including skeletal muscle, indicates that the native embryonic P2X receptors could be heteromultimeric. (C) 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.