Effects of a P2Y(12) receptor antagonist on the response of equine platelets to ADP. Comparison with human platelets.
Horses show susceptibility to platelet-related disorders. Equine platelets differ from human platelets in some of their responses, so information available about human platelets must be validated in the horse. Aggregation of platelets by ADP involves both P2Y(1) and P2Y(12) receptors on the platelet surface. We have compared the effect of the P2Y(12) antagonist, AR-C67085, on equine and human platelets in vitro using turbidimetric aggregometry to measure the rate and final extent of aggregation. Aggregation profiles, concentration-response curves and pA(2) values show that the rate of aggregation of equine platelets is much more susceptible to inhibition by AR-C67085 than that of human platelets. This species difference may reflect differences in the relative numbers of P2Y(1) and P2Y(12) receptors, or in intracellular signalling pathways, but will need to be considered by equine clinicians before using P2Y(12) antagonists in the treatment of thrombotic conditions.
Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, UK.
G
G
Mateos-Trigos
R J
RJ
Evans
M F
MF
Heath
D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000249:Adenosine Monophosphate / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D006736:Horses; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects; D058919:Purinergic P2 Receptor Antagonists
C117445:AR C67085MX; D058919:Purinergic P2 Receptor Antagonists; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate