Objective To examine the effects of methylmercury on oxidative damage in cerebrum of rats and the protective effects of taurine on the oxidative damage.
Methods Twenty-four rats were randomly divided into four groups by weight:control (saline), low methylmercury (4 μmol/kg), high methylmercury (12 μmol/kg), and taurine intervention groups (4 μmol/kg methylmercury + 1 mmol/kg taurine). Exposure started from Monday to Friday by intraperitoneal injection and lasted four weeks. Two hours before the exposure on every Monday, Wednesday, and Friday, the control, low methylmercury, and high methylmercury groups were subcutaneously injected with 0.9% sodium chloride, and the taurine group was subcutaneously injected with 1 mmol/kg taurine. Twenty-four hours after the last exposure, the rats were neutralized, and the cerebral cortices were taken for detecting contents of reactive oxygen species (ROS), sulfydryl, carbonyl, malondialdehyde (MDA), activities of super oxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and apoptosis rate.
Results The body weights of animals increased less in the low and the high methylmercury group (P<0.05 and P<0.01) respectively than that in the control group. The contents of ROS in the low and the high methylmercury groups were 1.8 and 3.9 times respectively of the control group (both P<0.01); the activities of SOD and GSH-Px decreased, the contents of sulfydryl decreased, the contents of carbonyl and MDA increased, and the apoptosis rates increased 3.4 and 10.0 times respectively. Compared with the high methylmercury group, the content of ROS of the taurine group reduced by17%, the activities of SOD and GSH-Px increased, the content of sulfydryl, carbonyl, and MDA also changed, and the apoptosis rate was 44% of reported in the high methylmercury group.
Conclusion Methylmercury can lead to oxidative damages in rat cerebral cortices, and taurine shows protective effects on methylmercury-induced oxidative damages.
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