Effect of adenosine A_2A receptor antagonists on motor disorders induced by 6-hydroxydopamine in rat¹

PURPOSE:

To investigate the role of adenosine A_2A receptors on 6-OHDA-induced motor disorder in rat.

METHODS:

In order to induce experimental model of Parkinson's disease, 6-hydoxydopamine (8 μg/rat) was injected unilaterally into the SNc. After three weeks as a recovery period, 6-OHDA-induced bradykinesia and balance disturbances were assessed by using beam traversal test 10, 30 and 60 minutes after intraperitoneal injections of the drugs (caffeine, SCH58261).

RESULTS:

The results showed that 6-OHDA (8 μg/rat, Intra-SNc) induced motor disorders of Parkinson's disease and increased elapsed time in the beam test (p<0.001). Injection of caffeine (30 mg/kg, i.p.) and SCH58261 (2 mg/kg, i.p.) attenuated elapsed time on beam (p<0.01 and p<0.001). We showed that acute administration of caffeine and SCH 58261 can improve the 6-OHDA-induced bradykinesia and motor disturbance.

CONCLUSION:

Adenosine A_2AR antagonists improve 6-OHDA-motor deficit and this effect seems to be mediated by the inhibition of A_2A presynaptic receptors in substantia nigra pars compacta.

Receptor, Adenosine A2A; Oxidopamine; Parkinson Disease; Rats