维生素C对慢性铅暴露小鼠海马NMDAR表达的影响

目的探讨维生素C对慢性铅暴露小鼠海马N-甲基D-天冬氨酸受体(NMDAR)表达的影响。方法将健康昆明系小鼠随机分为染铅组(从出生第l天起饲以醋酸铅水溶液9.6mmol/L)、维生素C给药组(从出生第l天起饲以醋酸铅9.6mmol/L及维生素C 7.5mL/kg水溶液)及对照组(饲以不含铅的饮用水),每组9只。小鼠于出生21d后断颈处死,采静脉血检测血铅浓度,并同时采用逆转录-聚合酶链反应(RT-PCR)检测其海马中NMDAR亚单位的表达水平。结果维生素C给药组小鼠的血铅浓度显著低于铅染组,但仍然高于对照组(P<0.01),维生素C给药组小鼠海马细胞的NMDAR亚单位ε1mRNA表达水平较染铅组明显提高(P<0.01),而ε2mRNA表达水平基本不变(P>0.05)。结论维生素C可降低染铅小鼠的血铅浓度,并可以影响小鼠海马NMDAR的表达水平,对海马细胞具有一定保护作用。

Effects of Vitamin C on expression of NMDAR in hippocampus of mice chronically exposed to lead

Objective To explore effects of Vitamin C on the expression of N-methyl-D-aspartate receptor(NMDAR) in hippocampus of mice chronically exposed to lead.Methods The healthy Kunming mice were randomly divided into lead-exposed group(fed with 9.6 mmol/L lead acetate in drinking water from the first day of birth),Vitamin C treatment group(fed with 9.6 mmol/L lead acetate and 7.5 mL/kg Vitamin C in drinking water from the first day of birth) and control group(fed with lead-free drinking water),with 9 mice in each.Mice were sacrificed by cervical dislocation on day 21 after birth.Venous blood was collected to detect the serum lead concentration and RT-PCR was employed to inspect the expression level of NMDAR subunit in their hippocampus.Results Concentration of serum lead of mice in Vitamin C treatment group was significantly lower than that in lead-exposed group,but still higher than that in control group(P<0.01).Compared with lead-exposed group,mRNA expression level of ε1 subunit of NMDAR in hippocampus of mice in Vitamin C treatment group was markedly increased,while that of ε2 subunit was basically unchanged(P>0.05).Conclusion Vitamin C can lower concentration of serum lead,affect the expression of NMDAR in hippocampus of lead-exposed mice,and exhibits protective effect on hippocampal cells.