title: An introduction to the endocannabinoid system: from the early to the latest concepts.
abstract: A rather complex and pleiotropic endogenous signalling system was discovered in the late 1990s, starting from studies on the mechanism of action of Delta(9)-tetrahydrocannabinol, the major psychoactive principle of the hemp plant Cannabis sativa. This system includes: (1) at least two G-protein-coupled receptors, known as the cannabinoid CB(1) and CB(2) receptors; (2) the endogenous agonists at these receptors, known as endocannabinoids, of which anandamide and 2-arachidonoylglycerol are the best known; and (3) proteins and enzymes for the regulation of endocannabinoid levels and action at receptors. The number of the members of this endocannabinoid signalling system seems to be ever increasing as new non-CB(1) non-CB(2) receptors for endocannabinoids, endocannabinoid-related molecules with little activity at CB(1) and CB(2) receptors, and new enzymes for endocannabinoid biosynthesis and degradation are being identified every year. The complexity of the endocannabinoid system and of its physiological and pathological function is outlined in this introductory chapter, for a better understanding of the subsequent chapters in this special issue.
authors.affiliation: Endocannabinoid Research Group, Institute of Biomolecular Chemistry and Institute of Cybernetics, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, Comprensorio Olivetti, 80078 Pozzuoli, Naples, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: De Petrocellis
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Di Marzo
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000502:physiology; D063385:Cannabinoid Receptor Modulators / Q000096:biosynthesis / Q000502:physiology*; D002352:Carrier Proteins / Q000502:physiology; D063388:Endocannabinoids; D006801:Humans; D053284:Polyunsaturated Alkamides; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists / Q000037:antagonists & inhibitors; D043885:Receptor, Cannabinoid, CB2 / Q000819:agonists / Q000037:antagonists & inhibitors; D043882:Receptors, Cannabinoid / Q000502:physiology; D050916:TRPV Cation Channels / Q000502:physiology
chemical_list: D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D002352:Carrier Proteins; C540799:Cnrip1 protein, rat; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D043882:Receptors, Cannabinoid; D050916:TRPV Cation Channels; C078814:anandamide