Nomenclature and classification of membrane receptors and their subtypes

: Present rapid growth of information about receptors for endogenous ligands and drugs requires changes in definitions, nomenclature and classifications of receptors and their subtypes. Receptors are defined as such membrane structures for which we have sufficiently reliable characterization of their structure, transducing mechanisms (mediation of intracellular effects), and selectively acting drugs (operational criterion). This characterization is based on the integrated approach to classification that relies on all three essential criteria. The current classification of membrane receptors is organized by International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification (NC-IUPHAR). Their conclusions about receptor classifications are regularly published in pharmacological journals and in special publications. List of presently known membrane receptors and their subtypes is provided in this review.