P2 Purinoceptors: Historical Perspective and Classification

Abstract

This article presents an overview that gives some historical perspective to the detailed papers at the cutting edge of P2 purinoceptor research that follow. I consider the proposal, first put forward by Abbracchio & Burnstock (Pharmacol Ther 64:445–475, 1994), that P2 purinoceptors should be regarded as members of two main families: a P2X purinoceptor family consisting of ligand‐gated ion channels, and a P2Y purinoceptor family consisting of G protein‐coupled receptors. The latest subclasses of these two families (P2X_1–4, and P2Y_1–5), identified largely on the basis of molecular cloning and expression, are tabled. Finally, I suggest some future directions for P2 purinoceptor research, including studies of the long‐term (trophic) actions of purines, the evolution and development of purinoceptors and therapeutic applications.