NEURODEVELOPMENTAL STUDIES OF LEAD POISONING

在三年的时间里，我们将检查体外细胞培养 神经毒性和神经发育影响系统 由无机和有机铅(铅)化合物在 环境。 我们打算研究这种重金属对体外培养的 准确反映活体中枢神经系统的实验系统 功能和发展。这种细胞培养系统提供了 将神经元和神经胶质细胞暴露于已知的 不同发育阶段潜在毒素的浓度 分期并允许直接评估神经损伤和 恢复以及对潜在分子的探索 机制和可能的干预方法。 从16日龄胎鼠脑中分离出的细胞 制成单细胞悬液，然后放入旋转培养中 它们通过重新聚集来恢复生长和分化， 发展轴突网络，髓鞘形成，并展示 神经递质的合成、储存、释放和摄取。在四点 体外发育阶段(相当于戊二酸甲酯， 新生儿、青少年和青壮年中枢神经系统)的影响 无机和有机铅化合物在随后 发育事件与神经元和神经胶质细胞的组织 细胞应通过将重组聚集体暴露于四个 不同浓度的铅化合物24小时。在 收获时，应将等量的重组骨料带到 确定这些先导化合物对1)的影响 重组集合体的细胞组织由以下决定 常规显微镜和电子显微镜，2)蛋白质和 磷蛋白组成3)髓鞘膜合成，4) 涉及第二信使的信号转导机制 系统。对照细胞应从处理过的烧瓶中取出 相同，但其中没有添加铅化合物。 特定中枢神经系统的解剖学、生理学和 铅在不同发育阶段引起的生化变化 使用这种体外实验系统的阶段将提供 用于预防和可能用于治疗的信息 干预与铅有关的分子过程 神经毒性作用。

Over a three year period we will examine an in vitro cell culture system for the neurotoxic and neurodevelopmental effects caused by inorganic and organic lead (Pb) compounds commonly found in the environment. We intend to study the influence of this heavy metal on an in vitro experimental system that accurately reflects in vivo CNS function and development. This cell culture system offers the advantage of exposing neurons and glial cells to known concentrations of potential toxins at diffferent developmental stages and permits direct assessment of neural damage and recovery as well as exploration of the underlying molecular mechanisms and possible intervention methods. Cells from 16 day old embryonic mouse brains shall be dissociated into single cell suspensions and placed into rotary culture where they resume their growth and differentiation by reaggregating, developing axonal networks, myelinating, and exhibiting neurotransmitter synthesis, storage, release and uptake. At four stages of in vitro development (equivalent to the prenate, neonate, adolescent and young adult CNS), the effects of inorganic and organic lead compounds on subsequent developmental events and the organization of neuronal and glial cells shall be evaluated by exposing the reaggregates to four different concentrations of lead compounds for 24 hours. At the time of harvesting, aliquots of reaggregates shall be taken to determine the influence of these lead compounds on 1) the cellular organizaiton of the reaggregates as determined by conventional and electron microscopy, 2) protein and phosphoprotein composition 3) myelin membrane synthesis, and 4) signal tranduction mechanisms involving second messenger systems. Control cells shall be taken from flasks treated identically, but in which no lead compound has been added. Definition of the specific CNS anatomical, physiological and biochemical changes caused by lead at various developmental stages using this in vitro experimental system will provide information for preventing and possibly therapeutically intervening in the molecular processes responsible for lead's neurotoxic effects.