Dopamine peroxidation: new evidences in human cerebellum

The cerebellum is a brain area not traditionally considered dopaminergic, but the presence of neuronal elements, indicative of dopaminergic neurotransmission, suggest that it may contribute to the motor symptoms or dyskinesia seen in Parkinson’s disease. We have recently reported on in gel-detection of a dopamine (DA) peroxidizing activity from human midbrain tissue, by using DA and hydrogen peroxide as substrates. This enzymatic reaction, analysed by mass spectrometry, revealed the presence of proteins that may play a role in neurodegenerative disease, highlighting a possible functional ling among DA redox cycle and protein metabolism. In order to investigate on the functional release of DA occurring in the cerebellum, we analysed this human brain region by using the in gel detection of DA peroxidising activity, by us set out, combined by mass spectrometry analysis. A strong red-orange activity band, similarly to that previously developed from human midbrain tissue, appeared in the cerebellar total vermis, cortex and central white matter. Mass spectrometry analysis of the specific activity bands in now in progress in order to identify the proteins responsible of the enzymatic reaction. These results, validating our method of investigation, would allow us a better understanding of the dopaminergic system and the related oxidative metabolism of DA.