Towards a revised nomenclature for P1 and P2 receptors

Abstract

The classification of receptors for adenosine, ATP and ADP (collectively called purinoceptors) has seen a number of developments in the past three years. The important division of receptors into two major classes 1 (1) adenosine (P 1 ) receptors and (2) P 2 purinoceptors, first suggested by Burnstock in 1978 (Ref.2), has been an abiding one that has set the stage for further subdivision of P 2 purinoceptors into P 2X and P 2Y subtypes on the basis of pharmacological properties 3 . Later, Dubyak 4 summarized the evidence that ATP worked through two different transduction mechanisms: intrinsic ion channels and G protein-coupled receptors. This information, coupled with the cloning of purinoceptors in 1993/94, led Abbracchio and Burnstock 5 to propose that purinoceptors should be classified in two families: G protein-coupled receptors termed P2Y purinoceptors, and intrinsic ion channels termed P2X purinoceptors. Developments in recent years have borne out these expectations and a revised nomenclature, essentially adopting the Abbracchio and Burnstock proposal, can now be proposed.

Structurally related nucleotides as selective agonists and antagonists at P2Y1 receptors

“…Modulation of adenosine receptors (P1) and nucleotide (P2) receptors by selective agonists and antagonists [1,2] has the potential for the treatment of a wide range of diseases, including those of the cardiovascular, inflammatory, and central nervous systems. Extracellular nucleotides, principally ATP, ADP, UTP, and UDP, act through two families of membrane-bound P2 receptors: P2Y subtypes, all of which are G protein-coupled receptors (GPCRs), generally coupled to phospholipase C (PLC); and P2X subtypes, ligandgated ion channels.…”

Age‐related changes in the localization of P2X (nucleotide) receptors in the rat adrenal gland

“…Such e ects of ATP are mediated through di erent types of receptors located on the surface of cells, consisting of two families of P2 receptors that are widely distributed among mammalian cells: P2X receptors are ligand-gated non-selective cation channels; while P2Y receptors are G protein-coupled membrane receptors [1,5,6]. So far, seven subtypes of P2X receptors and nine subtypes of P2Y receptors have been identi®ed [1,9,17,31].…”

Carbamazepine-Induced Upregulation of Adenosine A1-Receptors in Astrocyte Cultures Affects Coupling to the Phosphoinositol Signaling Pathway

“…Adenosine A 1 -and A 2 -receptor subtypes were originally distinguished by their differential effects on adenylyl cyclase (van Calker et al 1978(van Calker et al , 1979, but more recent findings have revealed coupling of adenosine receptors to other signal transduction systems including phospholipase C (PLC) (Miller and Hoffman 1994;Fredholm et al 1994). Very often, the coupling of adenosine A 1 -receptors to PLC ␤ is synergistic with the stim- NO .…”

“…CBZ may even have advantages as compared to lithium in the treatment and prophylaxis of schizoaffective and rapid cycling bipolar disorders (for review see Solomon et al 1995). Among the various pharmacological effects of CBZ, its activity as a specific antagonist at adenosine A 1 receptors (van Calker et al 1991;Biber et al, 1996) may be particularly important, because this property could lead to alterations in the responsiveness of signal transduction systems in the brain (van Calker et al 1998), a mechanism believed to be instrumental also to lithium's beneficial effects in affective disorders (for review see Manji et al 1995).Adenosine A 1 -and A 2 -receptor subtypes were originally distinguished by their differential effects on adenylyl cyclase (van Calker et al 1978(van Calker et al , 1979, but more recent findings have revealed coupling of adenosine receptors to other signal transduction systems including phospholipase C (PLC) (Miller and Hoffman 1994;Fredholm et al 1994). Very often, the coupling of adenosine A 1 -receptors to PLC ␤ is synergistic with the stim- NO .…”

“…Adenosine A 1 -and A 2 -receptor subtypes were originally distinguished by their differential effects on adenylyl cyclase (van Calker et al 1978(van Calker et al , 1979, but more recent findings have revealed coupling of adenosine receptors to other signal transduction systems including phospholipase C (PLC) (Miller and Hoffman 1994;Fredholm et al 1994). Very often, the coupling of adenosine A 1 -receptors to PLC ␤ is synergistic with the stim-ulation evoked by other receptors, such as ␣ 1 -adrenergic receptors (El-Etr et al 1989;Biber et al 1996Biber et al , 1997, histamine H 1 -receptors (Dickenson and Hill 1994), muscarinic receptors (Biden and Browne 1993), or thyrotropin receptors (Okajima et al 1995).…”