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背景:铅暴露引起的动物学习记忆障碍与脑细胞中蛋白激酶C(proteinkinaseC,PKC)活性改变是否有关系呢?目的:研究慢性铅暴露下发育期小鼠大脑组织PKC活性变化规律及其对小鼠记忆发育的影响。设计:以实验动物为研究对象,随机对照的验证性实验研究。单位:卫生部细胞生物学重点实验室。材料:实验在中国医科大学生物化学与分子生物学实验室完成。选择五六周龄昆明种小白鼠72只。方法:以不同浓度的醋酸铅饲喂交配后的雌鼠,其幼崽通过哺乳和直接饮水接触铅。在幼崽生后1d(P1),8d(P8),15d(P15),22d(P22),30d(P30)将其分别处死,取出脑组织。采用犤γ-32P犦ATP放射性磷标记法于体外测定铅暴露小鼠大脑组织的PKC的活性;另外取暴露于不同浓度醋酸铅的发育期小鼠,通过被动回避反应实验进行记忆行为学训练和测试,观察不同浓度的铅对小鼠记忆的影响。主要观察指标:①不同浓度铅暴露对发育期小鼠大脑组织内PKC活性的影响。②不同浓度铅暴露对发育期小鼠记忆行为的影响。结果:对幼鼠脑PKC的活性测定显示:在发育初期铅暴露小鼠脑中PKC活性高于正常,发育后期则低于正常,高浓度铅对PKC活性抑制较强;记忆行为学测试可见低浓度铅使小鼠发育初期记忆曲线升高,而使中长期记忆曲线减低;铅浓度升高,记忆曲线降低。结论:铅对小鼠大脑
BACKGROUND: Whether the learning and memory impairment caused by lead exposure is related to the alteration of PKC activity in brain cells? Objective: To study the changes of PKC activity in brain tissues of mice exposed to chronic lead exposure and its effect on small Effects of mouse memory development. Design: The experimental animal as the research object, a randomized controlled experimental study. Unit: Ministry of Health Key Laboratory of Cell Biology. Materials: The experiment was completed in the Laboratory of Biochemistry and Molecular Biology, China Medical University. Select five or six weeks Kunming mice 72. METHODS: Female mice were fed with different concentrations of lead acetate and their pups were exposed to lead through lactation and direct drinking. The pups were sacrificed on day 1 (P1), 8d (P8), 15d (P15), 22d (P22) and 30d (P30) respectively, and the brain tissue was removed. The activity of PKC in the brain of lead-exposed mice was measured in vitro by γ-32P 犦 ATP radioactive phosphorus labeling method. In addition, mice in developmental stages exposed to different concentrations of lead acetate were trained and tested for memory behavior by passive avoidance reaction The effects of different concentrations of lead on the memory of mice were observed. MAIN OUTCOME MEASURES: ① Effect of different concentrations of lead exposure on PKC activity in mouse brain during development. Effects of different concentrations of lead exposure on memory behavior in developing mice. Results: The activity of PKC in the brain of young rats showed that PKC activity in the brain of lead-exposed mice was higher than normal at the early stage of development, and was lower than that at the late stage of lead exposure. High concentrations of lead inhibited PKC activity strongly, and memory behavior test showed low Concentration of lead in the early development of mice memory curve increased, leaving the long-term memory curve decreased; lead concentration increased, memory curve decreased. Conclusion: Lead on mouse brain