Acta Cirúrgica Brasileira - Vol. 31 (2) 2016 - 133 8 – ORIGINAL ARTICLE EXPERIMENTAL NEUROLOGY Effect of adenosine A 2A receptor antagonists on motor disorders induced by 6-hydroxydopamine in rat 1 Siamak Reyhani-Rad Ι , Javad Mahmoudi ΙΙ DOI: http://dx.doi.org/10.1590/S0102-865020160020000008 Ι PhD, Assistant Professor, Department of Laboratory Sciences, Marand Branch, Islamic Azad University, Marand, Iran. Concept, design and intellectual content of the study; critical revision. ΙΙ PhD, Assistant Professor, Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran. Concept and design of the study, acquisition of data. ABSTRACT 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 g/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 g/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 2A R antagonists improve 6-OHDA-motor defcit and this effect seems to be mediated by the inhibition of A 2A presynaptic receptors in substantia nigra pars compacta. Key words: Receptor, Adenosine A2A. Oxidopamine. Parkinson Disease. Rats.