Table 2

Effect of CB1 receptor agonists on basal cAMP accumulation in CHO cells expressing the hCB1 cannabinoid receptor

LigandReceptor binding affinityStimulation of basal cAMP accumulation
pKi pEC50 % basal accumulation
Anandamide6.2  ± 0.15.1  ± 0.1627  ± 123  (141%)2-a
CP-55,9408.6  ± 0.26.0  ± 0.3374  ± 121 (84%)
HU-2109.2  ± 0.36.9  ± 0.1193  ± 13  (43%)
THC7.5  ± 0.26.6  ± 0.422.3  ± 2.5 (5%)2-a
WIN-55212-27.5  ± 0.46.5  ± 0.3445  ± 66  (100%)
  • Values are the mean and S.E. for values obtained from at least six concentration-response curves. Numbers in parentheses are activity values normalized to those of WIN-55212-2.

  • 2-a An SR141716A-insensitive component of the response was subtracted so as to derive an estimate of CB1 receptor-mediated activity. pEC50 and pKi values are the negative log of the molar EC50 and Kivalues, respectively.