Discriminative stimulus- and open-field effects of the enantiomers of 11-hydroxy-delta-8-tetrahydrocannabinol in pigeons and gerbils.
T U Järbe, R Mechoulam, J Zahalka
Pharmacology, biochemistry, and behavior January 1994 DOI: 10.1016/0091-3057(94)90119-8 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Animal behavioral pharmacology study Peer reviewed |
|---|---|
| Population | Pigeons trained to discriminate (-)-delta-9-THC and Mongolian gerbils |
| Interventions | (-)-11-OH-delta-8-THC (+)-11-OH-delta-8-THC (-)-delta-9-tetrahydrocannabinol |
| Dose | 0.17 mg/kg (ED50 for (-)-11-OH-delta-8-THC), 3 mg/kg ((+)-11-OH-delta-8-THC) |
| Topics | Cannabis |
| Key points | (-)-11-OH-delta-8-THC showed cannabimimetic activity in pigeons with an ED50 of 0.17 mg/kg, similar to delta-9-THC but with a shorter duration of action, while (+)-11-OH-delta-8-THC showed no cannabimimetic activity. In gerbils, (-)-delta-9-THC and (-)-11-OH-delta-8-THC suppressed rearing, but (+)-11-OH-delta-8-THC did not. The authors argue these results support cannabimimetic enantiospecificity. |
Abstract
The cannabimimetic activity of the two enantiomers of 11-hydroxy-delta-8-tetrahydrocannabinol (11-OH-delta-8-THC) was evaluated in pigeons trained to discriminate between the presence and absence of (-)-delta-9-tetrahydrocannabinol [(-)-delta-9-THC]. (-)-11-OH-Delta-8-THC exhibited cannabimimetic activity with a potency (ED50, 0.17 mg/kg) similar to that of delta-9-THC. The duration of action for (-)-11-OH-delta-8-THC was shorter than that observed for delta-9-THC. No cannabimimetic activity was seen after administrations of (+)-11-OH-delta-8-THC, indicating enantiomeric selectivity for the discriminable effects. A dose-related decrease in response rate occurred with (-)-11-OH-delta-8-THC, but not with (+)-11-OH-delta-8-THC; the latter compound produced an increase in responding at 3 mg/kg. Open-field behavior in Mongolian gerbils indicated marked suppression of rearing (vertical activity) after treatments with (-)-delta-9-THC and (-)-11-OH-delta-8-THC; this did not occur after (+)-11-OH-delta-8-THC. The results support the notion of cannabimimetic enantiospecificity.