Procedure | Cannabinoid | Concentration | Effect on twitch amplitude | Ref | |
Supramaximal stimulation of whole ileum at 0.1 Hz (ethanol) | (–)-Δ8-THC | 79.5 nM | Inhibition | 9 | |
(+)-Δ8-THC | 318nM | None | |||
(–)-11-OH-Δ9-THC | ca. 3 nM upwards | Inhibition | |||
(+)-11-OH-Δ9-THC | 61 nM | None | |||
Stimulation of whole ileum at 0.1 Hz (ethanol) | (–)-Δ9-THC | 1-150EC50=100 nM | Inhibition | 10 | |
(+)-Δ9-THC | 2 μM | None | |||
Supramaximal stimulation of MPLM at 0.2 Hz (Cremophor EL) | (–)-Δ9-THC | 1-150EC50=125 nM | Inhibition | 11 | |
(+)-Δ9-THC | 1-150EC50=3.1 μM | Inhibition | |||
Supramaximal stimulation of MPLM at 0.1 Hz (Tween 80) | HU-210 | 1-150EC50=1.4 nM | Inhibition | 12 | |
HU-211 | 1-150EC50 >316 nM | Inhibition (316 nM) | |||
Supramaximal stimulation of MPLM at 0.1 Hz (Tween 80) | CP559401-151 | 1-150EC50=3.5 nM | Inhibition | 13 | |
CP56667 | 1-150EC50=162.9 nM | Inhibition | |||
Supramaximal stimulation of MPLM at 0.1 Hz (Tween 80) | (+)-WIN55212 | EC50=5.5 nM | Inhibition | 13 14 | |
(–)-WIN55212 | 1 μM | Negligible |
↵1-150 Concentration producing 50% inhibition of the twitch response. Cannabinoid vehicle used is shown in paraentheses.
↵1-151 CP55940 has also been found to be more potent than CP56667 as a twitch inhibitor of mouse MPLM.15
CP56667 is the (+)-enantiomer of CP55940 and HU-211 is the (+)-enantiomer of HU-210 (dimethylheptyl-11-hydroxy-Δ8-tetrahydrocannabinol).
The samples of (+)-Δ8-THC and (+)-Δ9-THC used probably contained 5–10% of the corresponding (−)-enantiomer.16