Allopurinol suppresses para-nonylphenol and 1-methyl-4-phenylpyridinium ion (MPP(+))-induced hydroxyl radical generation in rat striatum.

We recently demonstrated that para-nonylphenol, an environmental estrogen-like chemical, enhances hydroxyl radical (*OH) generation in the rat striatum. In the present study we have examined whether para-nonylphenol enhanced 1-methyl-4-phenylpyridinium ion (MPP(+))-induced *OH generation in the rat striatum using a microdialysis technique. Para-nonylphenol significantly enhanced MPP(+)-induced *OH generation. Further, we studied the effect of allopurinol, a xanthine oxidase inhibitor, on para-nonylphenol and MPP(+)-induced *OH generation. Allopurinol significantly suppressed para-nonylphenol and MPP(+)-induced *OH generation. The results indicate that para-nonylphenol enhanced *OH generation based on superoxide anion production, and allopurinol may have preventive effect on para-nonylphenol and MPP(+)-induced *OH generation.