SR144528 is a highly potent, selective and orally active antagonist of CB2 receptor with Ki of 0.6 nM.
SR144528 displays 700-fold lower affinity (Ki= 400 nM) for CB1 receptors, and no affinity for any of the more than 70 receptors, ion channels or enzymes (IC50>10 uM).
SR144528 antagonizes the inhibitory effects of CP 55,940 on forskolin-stimulated adenylyl cyclase activity with EC50 of 10 nM in cell-based assays, selectively blocks the MAPK activity induced by CP 55,940 with IC50 of 39 nM.
SR144528 displaces the ex vivo [3H]-CP 55,940 binding to mouse spleen membranes (ED50=0.35 mg/kg) with a long duration of action.
