Discriminative Stimulus Effects of Delta-9-Tetrahydrocannabinol and Delta-9-11-Tetrahydrocannabinol in Rats and Rhesus-Monkeys
Wiley, J., Barrett, R. L., Britt, D. T., Balster, R. L., & Martin, B. R. (1993). Discriminative Stimulus Effects of Delta-9-Tetrahydrocannabinol and Delta-9-11-Tetrahydrocannabinol in Rats and Rhesus-Monkeys. Neuropharmacology, 32(4), 359-365.
Previous reports have suggested that DELTA9-11-tetrahydrocannabinol (DELTA9-11-THC), an exocyclic analog of DELTA9-tetrahydrocannabinol (DELTA9-THC), may have weak agonist effects as well as antagonistic properties. Tle purpose of the present study was to examine the effects of DELTA9-11-THC in substitution and antagonism tests in rats and in rhesus monkeys trained to discriminate DELTA9-THC from vehicle in two-lever drug-discrimination procedures. The substitution studies showed that DELTA9-11-THC generalizes from the training dose of DELTA9-THC in rats and in monkeys, although it was less potent in both species. The magnitude of the potency difference was greater in monkeys than in rats. When administered immediately following injection with the training dose of DELTA9-THC, DELTA9-11-THC failed to block the DELTA9-THC cue in rats and showed a lack of dose-responsive inhibition in monkeys. These results suggest that DELTA9-11-THC is devoid of antagonistic properties in the drug discrimination paradigm