title: Biology and pharmacology of the platelet P2Y12 receptor.
abstract: Platelets possess two receptors for ADP, P2Y(1) and P2Y(12). ADP is released from platelet dense granules upon platelet activation by numerous agonists and thereby amplifies platelet responses regardless of the initial stimulus. The P2Y(1) receptor is one of many platelet receptors coupled to Gq and initiates ADP-induced activation. The P2Y(12) receptor on the other hand is linked to Gi and plays a special role in the amplification of platelet activation initiated by numerous other pathways. Platelet activation leads to a range of responses that play a critical role in arterial thrombosis and the inflammatory responses associated with this, including platelet aggregation, dense and alpha granule secretion and procoagulant activity. P2Y(12) receptor activation yields powerful amplification of these processes such that P2Y(12) receptor antagonists may have dramatic inhibitory effects on platelet function regardless of the activating stimuli. This phenomenon, coupled with the restricted distribution of the P2Y(12) receptor in humans, makes the receptor an ideal target for pharmaceutical therapy. This has already been established by the therapeutic success of clopidogrel, which acts, via an active metabolite, on this receptor. However, current therapeutic regimens of clopidogrel yield variable and incomplete P2Y(12) receptor blockade and more effective strategies to block P2Y(12) receptor activation offer the potential of greater clinical efficacy.
authors.affiliation: Cardiovascular Research Unit, Clinical Sciences Centre, University of Sheffield, Northern General Hospital, Herries Road, Sheffield, S5 7AU, UK. r.f.storey@sheffield.ac.uk
authors.forename: Robert F
authors.initials: RF
authors.lastname: Storey
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000502:physiology*; D015539:Platelet Activation / Q000187:drug effects / Q000502:physiology; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2 / Q000187:drug effects* / Q000502:physiology*; D058925:Receptors, Purinergic P2Y12; D013988:Ticlopidine / Q000494:pharmacology
chemical_list: D008565:Membrane Proteins; C548576:P2RY12 protein, human; D010975:Platelet Aggregation Inhibitors; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; D058925:Receptors, Purinergic P2Y12; D013988:Ticlopidine