CB1 inactivation interferes with ERK and Akt signaling pathways involved in angiogenesis. (A) Western blot of endothelial cells pretreated with CB1 antagonist SR141716 (30 minutes, 0.3μM) and stimulated with bFGF (10 ng/mL) for increasing time points (0, 15 minutes, 30 minutes, 24 hours). Vertical lines have been inserted to indicate a repositioned gel lane. (B) Western blot of endothelial cells transfected with either control siRNA or CB1-siRNA for 24 hours. (A-B) Quantification of the intensity of the bands calibrated to the intensity of total protein bands and loading control (means ± SD; ANOVA vs control, **P < .01).