Adenosine A(2A) receptor mRNA expression in Parkinson's disease

The expression of the human adenosine AZA receptor was examined by reverse transcription polymerase chain reaction in post-mortem human brain tissue t hat was obtained from normal subjects and patients who died with Parkinson' s disease. Adenosine APA receptor mRNA was detected in both striatal (nucle us accumbens, caudate nucleus and putamen) and extrastriatal (globus pallid us and substantia nigra) brain regions. A significant decrease in the level of adenosine APA receptor mRNA was found in the anterior and posterior cau date nucleus and anterior dorsal putamen, whereas a significant increase wa s observed in the substantia nigra pars reticulata of Parkinsonian brain wh en compared to agematched controls. No change in adenosine APA receptor mRN A levels was seen in any other brain region examined. This study demonstrat es that APA receptor mRNA expression is altered in the basal ganglia of pat ients who died with Parkinson's disease and who were receiving treatment wi th dopaminergic drugs. The adenosine APA receptor appears subject to regula tion by dopaminergic systems in human brain, though these data do not permi t a distinction to be made between the effects of neuronal degeneration or drug treatment. The adenosine AZA receptor may therefore form a target for the treatment of basal ganglia disease. (C) 2000 Published by Elsevier Scie nce Ireland Ltd.