Effects of PEA on 2-AG affinity and efficacy at the human CB2 receptor. a Displacement curves of 2-AG and PEA, alone and in combination, in a competition binding assay. The curves show the effect of increasing concentrations of 2-AG, PEA, or 2-AG plus PEA at displacing [3H]-CP-55,940 from the human recombinant CB2. All experiments were performed in membranes from HEK-293 cells overexpressing the human recombinant CB2 receptors. Data are the mean ± SEM. The effect of WIN55, 212-2 (10 μM) was considered as 100% displacement. b Concentration-response curves of 2-AG and PEA, alone and in combination, in a cAMP-based functional assay. The curves show the % of the response relative to the maximum effect observed on NKH-477-induced cAMP levels in CHO-Kl cells stably overexpressing the human recombinant CB2 receptor with increasing concentrations of 2-AG, PEA, or 2-AG following incubation with PEA.