Dopaminergic system does not play a major role in the precipitated cannabinoid withdrawal syndrome.

AIM To determine the dopaminergic system involvement in precipitated cannabinoid withdrawal syndrome. METHODS The dopamine D1 receptor antagonist SCH23390 or the dopamine D2 receptor antagonist sulpiride was administered to rats chronically treated with either delta 9-tetrahydrocannabinol (THC) or vehicle. Subjects were then injected with either SR141716A or vehicle and behavior was observed for 1 h. RESULTS Administration of the cannabinoid receptor antagonist SR141716A to animals chronically treated with THC as described by Tsou et al (1995) produced a profound withdrawal syndrome. Treatment with dopamine antagonists did not attenuate cannabinoid precipitated withdrawal syndrome in THC tolerant animals while the agonists increased the syndrome. CONCLUSION It is unlikely that the dopaminergic system plays a major role in mediating the behavioral aspects of the cannabinoid withdrawal syndrome.