慢性铅暴露对小鼠脑皮质区ERK蛋白表达的影响

Effect of Chronic Lead Exposure on Extracellular Signal Regulated Kinases in Cortex of Mouse

目的:研究不同浓度乙酸铅染毒对发育期不同时段小鼠脑皮质区细胞外信号调节激酶(extracellular signalregulated kinases,ERK)活力表达的影响。方法:分组饲养小鼠,对照组喂以蒸馏水;实验组于交配后改喂含不同浓度乙酸铅(2.4、4.8、9.6mmol/L)的水溶液。新生鼠通过母乳摄入铅,断乳后幼鼠自行饮水摄入铅。新生鼠按生后不同日龄(P7,P14,P21,P28)取脑皮质。利用ERK磷酸化抗体,通过蛋白免疫印迹法检测不同日龄、不同染铅浓度小鼠等量脑皮质中ERK活力表达。结果:Western blot结果显示,低浓度铅(2.4mmol/L)使ERK表达升高,中浓度铅(4.8mol/L)使ERK表达量降低,铅浓度升高至9.6mmol/L时随着铅浓度升高ERK表达量不再降低相反有所回升。结论:ERK1/2的水平随铅浓度升高而逐渐降低,铅对ERK的影响在发育后期比发育前期影响大。

Objective： To Study the effects of different concentrations of lead acetate on the extracellular signal regulated kinase （ERK） activity in the cerebral cortex of mice at different developmental stages. Methods： Mice were divided into experimental groups and control group. Mice in experimental groups were fed with lead acetate at different concentrations （2.4, 4.8 and 9.6mmol/L） after mating, while those in control group were fed with distilled water instead. The pups were exposed to lead through breasffeeding of their mother. The cerebral cortexes of the pups were dissected on days of 7^th, 14^th, 21^th and 28^th after their birth respectively. The ERK activities in their cerebral cortexes were de- termined with Western blot. Results： ERK expression in mice exposed to low concentration （2.4 mmol/L） of lead acetate increased, but decreased in mice exposed to middle high concentration of lead acetate（4.8 mmol/L） , and increased again in mice exposed to high concentration of lead acetate （9.6 mmol/L）. Conclusions： ERK expression around 1/2 level decreases gradually along with the increase of lead concentrations. The lead toxic effects to ERK expression in mice are bigger at late developmental stages than those at earlier stages.