Role Of Element Profile In Lead Induced Neurotoxicity

Objectives The current study is aimed to illuminate the change of element profile after lead exposure of SD rats, to investigate the effect of copper and copper transport proteins on the accumulation of copper of Pb-induced in C6 cells. Our finding will provide the basis for mechanism of lead induced toxicity.Methods 1 Establishment of the animal model. A total of 80 SD male rats, aged 21 d were randomly divided into control and Pb exposure group. Rats in control group were given 200mg/L sodium acetate in drinking water and rats in lead exposure group were given 200mg/L lead acetate in drinking water. The periods of treatment included 3 weeks, 6 weeks, 9 weeks and 12 weeks. Neurobehavioral change was tested by using Morris water maze. 2 Establishment of cell model C6 cells were treated with 0 or 10μmol?L-1 acetate lead for 24 h, and then cultured in medium with 2μmol?L-1 copper chloride for 0, 0.5, 1, 2, 4 and 8h. The cell viability of C6 was assessed by CCK-8. 3 ICP-MS was used to detect the element levels in the hippocampus, cortex and cerebrospinal fluid(CSF) of the rats and the C6 cells. 4 real-time PCR was used to detect the m RNA expression of CTR1, DMT1, CCS, ATOX1, COX17, ATP7 A and ATP7 B. 5 Laser con-focal microscopy was applied to detect the expression of CTR1 and ATP7 A in cells.Results 1 There was no significant difference in terms of body weight between two groups. 2 Morris water maze test results showed that escape latency of lead exposed group rats was longer from the sixth week to the twelfth week. 3 The significant changed elements in the hippocampus, cortex and CSF: The main significant changed element in the cortex of rats following lead exposure included Ca, Fe, Cu. The element including Na, Mg, Al, Cu, Zn were changed significantly in the hippocampus. Meanwhile, there is a certain difference of the elements of Na, Al, Cu, Fe, V, Ni in the cerebrospinal fluid. The main changed elements was Cu in hippocampus, cortex and cerebrospinal fluid. 4 Compared with the control group, the lead and copper concentrations in lead-treated C6 cell were increased and the difference were significant(P<0.05). After cells were cultured with medium with 2μmol?L-1 copper chloride for 0, 0.5, 1, 2, 4 and 8h, there was an increase trend in Pb-exposed cells in terms of Cu levels, and the interaction effect was existed between group and treating time(P<0.05). 5 Compared with control group, the CTR1 and DMT1 m RNA expression in lead treated C6 cells increased by 12% and 36% respectively, as well as the expression of ATP7 A m RNA decreased by 25%(P<0.05). Meanwhile, the ATP7 A fluorescent intensities were lower in lead-exposed cells than those in controls. In contrast, the CTR1 fluorescent intensities increased significantly compared with the controls. 6 At 8th of copper medium culture, the level of ATP7 A expression in C6 cells was significantly increased, while the expression of COX17 was significantly decreased.Conclusions 1 The main changed element in in hippocampus, cortex and CSF is copper. 3 Pb exposure dose lead to Cu accumulation, which may due to increasing the expression of DMT1, CTR1 and decreasing the expression of ATP7 A.