amg-3 and Pain

Newly developed cannabinoids may hold the promise of the development of useful and safe drugs. This study aimed to investigate the behavioral effects of the novel 1',1'-dithiolane delta8-HC analogue AMG-3, a cannabinomimetic molecule with high affinity for CB1/CB2 receptors. This analog was chosen for its binding affinity to these receptors, which is higher than that reported for delta8-tetrahydrocannabinol (delta8-THC). Behavioral responses were assessed after the administration of AMG-3 (1, 2, 4, 8 mg/kg, i.p.) in the open field, on the bar test, on the hot plate and in the intracranial self-stimulation procedure. AMG-3 increased the reactivity time on the hot plate in a dose- and time-dependent manner, indicating a long-lasting analgesic effect (at least 24 h). The substance was found dose-dependently to decrease spontaneous motor activity and to induce catalepsy, particularly at the highest dose (8 mg/kg). AMG-3 did not affect the rewarding value of intracranial self-stimulation, except to increase the reward threshold at the highest dose (8 mg/kg). The effects of the highest dose of AMG-3 on spontaneous activity and on the self-stimulation paradigm were completely reversed by pre-treatment with the CB1 receptor antagonist AM-251. These findings indicate that the administration of AMG-3 to rats elicits a specific behavioral profile, most probably associated with the activation of CB1 receptors and without effects indicating abuse potential.

Topics: Animals; Behavior, Animal; Binding, Competitive; Cannabinoids; Catalepsy; Cell Membrane; Cerebral Cortex; Cyclohexanols; Dose-Response Relationship, Drug; Male; Molecular Structure; Motor Activity; Pain; Pain Measurement; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Time Factors; Tritium