Acute effects of the cannabinoid receptor agonist WIN55212-2 on dopamine release in rat: an in vivo electrochemical study.

The aim of this study was to investigate the effects of the cannabinoid receptor agonist, WIN55212-2, and the cannabinoid receptor antagonist, SR141716A, on dopamine (DA) release evoked by KC1 (120 mM) microinjected into the striatum. The cannabinoid agonist WIN55212-2 (1 and 5 mg/kg, i.p.) dose-dependently attenuated DA release in the striatum, whereas the cannabinoid receptor antagonist SR141716A (3 mg/kg, i.p.) produced the opposite effect. SR141716A (3 mg/kg, i.p.) blocked the effects on DA release by WIN55212-2 (5 mg/kg, i.p.). Vehicle alone did not change DA release. These results suggest that cannabinoids modulate DA release in the striatum.