Table 2

Relative agonist efficacies for the stimulation of [35S]GTPγS binding and inhibition of adenylyl cyclase ([32P]cAMP) determined using a one-site model

Emax [35S]GTPγS %LevonantradolImax[32P]cAMP %Inhibition (%WIN55212-2)
Cerebellum
 WIN55212-2106  ± 2a 21  ± 2 (100 ± 5)a
 Levonantradol100  ± 6a
 CP5594074  ± 2b
 Methanandamide65  ± 4c 18  ± 3 (85 ± 5)a
 Δ9-THC20  ± 14-d 12  ± 1 (53 ± 7)b
Hippocampus
 WIN55212-2128  ± 2a
 Levonantradol100  ± 2b
 CP5594087  ± 3c
 Methanandamide86  ± 2c
 Δ9-THC27  ± 14-d
Hypothalamus
 WIN55212-2130  ± 6a
 Levonantradol100  ± 4b
 CP5594082  ± 5b
 Methanandamide104  ± 8b
 Δ9-THCΔ9-THC12  ± 2c

Agonist concentration-effect curves were generated for stimulation of [35S]GTPγS binding and inhibition of adenylyl cyclase ([32P]cAMP) in brain membranes. Emaxvalues for [35S]GTPγS binding and Imaxvalues for adenylyl cyclase inhibition were normalized to the values obtained by maximally effective concentrations of levonantradol (3 μM) or WIN55212-2 (1 μM), respectively, before curve fitting. Normalized values for adenylyl cyclase inhibition are shown in parentheses. Data are mean values ± S.E. from four separate experiments.

  • 4-d  Values labeled with different letters within a brain region are significantly different from one another (P < .05 by Tukey-Kramer test).