An involvement of globus pallidus (GP) in the antiparkinsonian effects of A2A receptor antagonists has been proposed on the basis of the selective localization of A2A receptors on the striatopallidal pathway. In order to investigate this possibility, the present study evaluated rotational behavior in unilaterally 6-hydroxydopamine-lesioned rats following infusion of the water-sol. A2A receptor antagonist SCH BT2 into GP. SCH BT2 (5 g/1 l) altered neither motor behavior nor produced postural asymmetry by itself. However, when infused concomitantly with a parenteral subthreshold dose of L-DOPA (3 mg/kg i.p.) capable of inducing modest contralateral rotational behavior (34.7 20.7/1 h), SCH BT2 significantly potentiated the no. of contraversive rotations (167.4 16.3/1 h). These results suggest that A2A receptors located in the globus pallidus may be involved in the antiparkinsonian effects of A2A antagonists.
Involvement of globus pallidus in the antiparkinsonian effects of adenosine A2A receptor antagonists.
BARALDI, Pier Giovanni;AGHAZADEH TABRIZI, Mojgan;
2006
Abstract
An involvement of globus pallidus (GP) in the antiparkinsonian effects of A2A receptor antagonists has been proposed on the basis of the selective localization of A2A receptors on the striatopallidal pathway. In order to investigate this possibility, the present study evaluated rotational behavior in unilaterally 6-hydroxydopamine-lesioned rats following infusion of the water-sol. A2A receptor antagonist SCH BT2 into GP. SCH BT2 (5 g/1 l) altered neither motor behavior nor produced postural asymmetry by itself. However, when infused concomitantly with a parenteral subthreshold dose of L-DOPA (3 mg/kg i.p.) capable of inducing modest contralateral rotational behavior (34.7 20.7/1 h), SCH BT2 significantly potentiated the no. of contraversive rotations (167.4 16.3/1 h). These results suggest that A2A receptors located in the globus pallidus may be involved in the antiparkinsonian effects of A2A antagonists.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
