FIG. 2.

Org27569 antagonizes cannabinoid agonist-induced ERK activation. HEK293 cells stably transfected with the hCB₁ receptor were exposed to specified agonists at their EC₈₀ values and Org27569 for 5 min. Protein was separated by SDS-PAGE and western blots for phospho-ERK normalized to total ERK and curves were fitted using GraphPad Prism 5.0 to calculate IC₅₀ values. (A) Org27569 concentration–response curve applied in combination with EC₈₀ of CP55,940 (6.1 nM). (B) Org27569 concentration–response curve in the presence of EC₈₀ THC (500 nM). (C) Org27569 concentration–response curve in the presence of EC₈₀ 2-AG (1.2 μM). Data are the mean ± SEM of three independent experiments. CP, CP55,940; Org, Org27569; V, vehicle.