Abstract:

Objective To investigate the gender differences of oxidative stress reactions in ventral mesencephalic (VM) dopamine neurons. Methods VM dopamine neurons of male and female Balb/c fetal mice were cultured, and were divided into control group (without treatment), rotenone group (treated with 25 nmol/L rotenone for 8 h) and estrogen+rotenone group (treated with 1×10^-7 mol/L 17 β-estradiol for 1 h and 25 nmol/L rotenone for 8 h). Immunohistochemistry was employed to observe the neuron injury of mice of different genders, MTT assay was adopted to measure the cell viability, and Western blotting was used to detect the expression of tyrosine hydroxylase (TH) protein in cells of mice of different genders. Results Immunohistochemistry revealed that cell injury of male mice was more severe than that of female mice, and cells of male mice with positive TH were more significant than those of female mice with positive TH in rotenone group. MTT assay indicated that there were significant differences in cell viability between male mice (66%) and female mice (75%) in rotenone group (P＜0.05), and cell viability of male mice (81%) and female mice (86%) in estrogen+rotenone group was significantly higher than that of mice of corresponding genders in rotenone group (P＜0.05). Western blotting demonstrated that the expression of TH protein in cells of male mice was significantly lower than that in cells of female mice in rotenone group (P＜0.05), and the expression of TH protein in estrogen+rotenone group was significantly higher than that of corresponding genders in rotenone group (P＜0.05). Conclusion There exist gender differences of oxidative stress reactions in VM dopamine neurons. Male is more vulnerable than female in respond to rotenone, and estrogen has protective effects on both male and female neurons.

Key words: dopamine neuron, oxidative stress, gender differences