Effect of cannabinoids on the abdominal constriction response in mice: within cannabinoid interactions

Abstract
After oral administration to mice, δ 9-tetrahydrocannabinol (THC) and cannabinol (CBN) caused a dosedependent suppression of the abdominal constriction response to formic acid. Cannabinol was 50 times less active than THC and cannabidiol (CBD) was without effect. The effects of THC and CBN were additive. CBD antagonised the antinociceptive effects of both THC and CBN in a dose-dependent manner.