Editorial: Purinergic Pharmacology

Abstract

The purine nucleotides and nucleosides constitute important extracellular signaling molecules acting as neurotransmitters and neuromodulators. Indeed, extracellular adenosine 5′-triphosphate (ATP) and adenosine, tightly controlled by nucleotidases, ribokinases, deaminases, and transporters, signal through a rich array of purinergic receptors. These receptors, which emerged early in evolution, are among the most abundant in living organisms controlling many physiological actions, thus becoming promising therapeutic targets in a wide range of pathological conditions. Thus, while P1 receptors are selective for adenosine, a breakdown product of ATP, P2 receptors are activated by purine nucleotides, as well as P2Y receptors being activated by pyrimidine nucleotides. Interestingly, purinergic receptors, both G protein-coupled (i.e., P1 and P2Y) and ligand-gated ion channel (i.e., P2X) receptors, are involved in many neuronal and non-neuronal mechanisms, including pain, immune responses, exocrine and endocrine secretion, platelet aggregation, endothelial-mediated vasodilatation and inflammation, among others.