RESUMO
<p><b>OBJECTIVE</b>To investigate the mechanisms of taurine (Tau) preventive effect on neurotoxicity induced by manganese (Mn) in rat's prefrontal cortex.</p><p><b>METHODS</b>SD rats were divided into four groups after one week of observation: normal control:the group animals received daily intraperitoneal (ip.) injections of sterile saline for 3 months; Mn treated group (Mn): rats received ip. injection of MnCl(2).4H(2)O once a day for 3 months; Tau preventive group (Mn + Tau): The Mn level of this group were the same as Mn's, the Tau level 200 mg/kg, three times per week, for 3 months; Tau treated group (Mn-->Tau): After received the daily injection of Mn as Mn group for 3 months, the rats received Tau three times per week for 3 months. The dose of Mn and Tau were the same as above. The experiment lasted 6 months.</p><p><b>RESULTS</b>(1) Mn induced apoptosis of neurons in rat's prefrontal cortex. The ratio of apoptosis of neurons in the Mn treated group [(20.0 +/- 4.3)%] was higher than that of the control group [(1.8 +/- 2.1)%] (P < 0.05) and the ratio of apoptosis in Tau preventive group (Mn + Tau) was lower than that of the Mn treated group (P < 0.05). (2) The production of MDA in Mn treated group was higher than the control group (P < 0.05) and the activity of SOD was lower than that in the control group. In Tau preventive group (Mn + Tau), Tau increased the activity of SOD and decreased the production of the MDA, with the significant difference level compared to the Mn treated group (P < 0.05).</p><p><b>CONCLUSION</b>Mn induces apoptosis in rat's prefrontal cortex neurons. The main mechanisms of Tau preventing cytotoxicity against Mn is the reduction of the oxidative stress in prefrontal cortex neurons.</p>