Synergistic Effects of Adenosine A2A Antagonist and L -DOPA on Rotational Behaviors in 6-Hydroxydopamine-Induced Hemi-Parkinsonian Mouse Model

In this study, we examined the combination effects of L-DOPA and adenosine receptor antagonists on rotational behaviors in a hemi-Parkinsonian mouse model induced by unilateral 6-hydroxydopamine (6-OHDA) injection. The adenosine A2A antagonist SCH-58261, but not the A1-receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine or A2B-receptor antagonist alloxazine, synergistically potentiated the L-DOPA-induced rotational behaviors in the 6-OHDA-lesioned mice. In addtion, the 6-OHDA-induced lesions of the dopaminergic system did not affect the in vivo binding of an adenosine A2A-receptor tracer [11C]SCH-442416 in the striatatum. These findings suggest that adenosine A2A antagonists are extremely useful for pharmacotherapy of L-DOPA in Parkinson’s disease patients.