ESTROGEN AS A NEUROPROTECTANT AGAINST MPTP-INDUCED NEUROTOXICITY IN C57 B1 MICE/

Castrated retired breeder male and female mice were treated or not wit h a 17 beta-estradiol pellet. At 10 days postcastration +/- estrogen t reatment all animals were treated with MPTP. Five days later, concentr ations of dopamine were determined from the corpus striatum and olfact ory tubercle. Both castrated male and female mice treated with estroge n had significantly greater concentrations of dopamine within the corp us striatum compared with their respective gender controls, which did not receive estrogen. By contrast, no statistically significant differ ences in olfactory tubercle dopamine concentrations were obtained. Ove rall concentrations of dopamine within the corpus striatum, but not ol factory tubercle, were substantially greater in female vs. male mice. These data demonstrate that treatment with estrogen prevents reduction s in corpus striatal dopamine concentrations in castrated mice treated with MPTP. Intersetingly, this effect of estrogen was observed in bot h male and female mice. These results suggest that estrogen may serve as a neuroprotectant against an agent that is toxic to the nigrostriat al dopaminergic system in both male and female animal models of Parkin sonism.