Involvement of adenosine receptors in dizocilpine-induced motor activity in mice

The effect of adenosine receptor ligands on dizocilpine-induced locomotion was studied in mice. Dizocilpine-induced hyperactivity (0.1 mg/kg ip) in mice was antagonized by all adenosine receptor agonists: CPA - A 1 receptor agonist, CGS 21680 - A 2 receptor agonist, and NECA - A 1 /A 2 agonist, but the effect ofNECA was the most apparent. Locomotion induced by the threshold dose of dizocilpine (0.05 mg/kg ip) was enhanced by DMPX (A 2A adenosine receptor antagonist) and by theophylline (A 1 and A 2 receptor antagonist), but not by A 1 receptor antagonist - CPT. These data suggest that adenosinergic system is involved in the mechanism of dizocilpine-induced hyperactivity, and it seems that A 2A adenosine receptor plays a more important role.