Metabotropic receptors for ATP and UTP: exploring the correspondence between native and recombinant nucleotide receptors

In the past five years, an extended series (P2Y(1-n)) of metabotropic nucle otide (P2) receptors has been cloned from vertebrate tissues; these recepto rs are activated by either ATP or UTP, or both nucleotides. While certain c loned P2Y receptors appear to correspond functionally to particular native P2 receptor phenotypes, such pharmacological phenotypes could be explained by either a combination of several members of the P2Y(1-n) series being coe xpressed in the same tissue or the existence of novel, uncloned P2Y subtype s. Here, Brian King, Andrea Townsend-Nicholson and Geoffrey Burnstock revie w recent findings on the matter of pharmacological relationships between na tive P2 and cloned P2Y receptors.