Specific impairment of ADP-induced platelet aggregation by cannabinoids.

The structure-activity relationship of the inhibition of ADP-induced platelet aggregation by cannabinoids was studied. A marked specificity was revealed: derivatives in which the two asymmetric centers have a configuration opposite to that of the natural cannabinoids and have a dimethylheptyl (DMH) side-chain were most inhibitory. It is concluded that the mode of inhibition includes a specific interaction of the cannabinoids with some membrane proteins, possibly including the receptor for ADP.