Figure 10.

[³⁵S]GTPγS binding to membranes from hCB₂-CHO cell membranes. The effect of (a) 1 μM cannabidiol (n=4–5) or (b) 100 nM SR144528 (n=5–6) on the mean log concentration–response curve of CP55940 for stimulation of [³⁵S]GTPγS binding to CB₂-transfected CHO cell membranes after subtraction of the inhibitory effect induced by either 1 μM cannabidiol or 100 nM SR144528 at the basal level of [³⁵S]GTPγS binding, determined in the absence of any other compound. Each symbol represents the mean percentage increase in [³⁵S]GTPγS binding±s.e.m. After this re-analysis, it was found that 1 μM cannabidiol did not produce a significant rightward shift of the CP55940 log concentration–response curve, whereas 100 nM SR144528 antagonized CP55940 with an apparent K_B value of 2.5 nM, with 95% CI of 1.6 and 4.3 nM.