Detection of dopamine DNA adducts: potential role in Parkinson's disease

Oxidation of catecholamines may lead to the formation of O-semiquinonesand o-quinones in catecholaminergic brain tissues, and thesereactive molecules may form DNA or protein adducts. In thisstudy, cultured cells were treated with dopamine (DA) for ²⁴h and ³²P-postlabeling was used to detect DA-DNA adducts. InHL–60 cells, 250µM DA induced 8.5 DNA adducts/108nucleotides; adduct formation was dose-dependent up to 500 µMDA. Addition of H2O2 increased the relative adduct levels ⁷-to 13-fold, but no adducts were detected when DA and ascorbicacid were added simultaneously. In human glioblastoma cell linesU87, U251, SF-763 and SF-767, 1000 µM DA produced 0.98–2.31adducts/108 nucleotides. These results suggest that the formationof DNA adducts by DA may contribute to the development of certainneurodegenerative diseases such as Parkinson's disease.