SYNERGISTIC EFFECTS OF PCBS AND DDE ON REPRODUCTION IN PEROMYSCUS

体内和体外研究将评估生殖和生育力 两种普遍存在的环境污染物，多氯联苯和DDE， 哺乳动物的生殖尽管这些化合物在1998年被禁止使用， 1970年代的美国，目前这两个组织的水平 人类和野生动物样本中的有机氯似乎已经达到 稳态这些化合物在子宫内通过胎盘转移 通过血液和母乳喂养使这些消除 短期内不太可能接触到新一代。PCBs和DDE 已经很好地研究了个别，但很少有工作已经做了 可能对这些污染物的繁殖产生协同效应， 与环境相关的暴露水平。 目前的多代调查将利用本地啮齿动物 作为评价脊髓灰质炎对人类危害的模型， 野生动物种群。交配对将通过饮食进行确认， 环境相关水平的5ppm多氯联苯（Aroclor 1254）和5ppm 在两组小鼠中单独使用p，p 'DDE，而第三组将 这两种污染物。对照组将接受相同的饮食 没有PCB或DDE。第一代曝光者的后代 与来自相同制度的动物配对，以观察两种 几代人的曝光。生殖和生育参数，包括 窝仔数、初生重、断奶成活率和断奶重将 在所研究的两代小鼠中的每一代中测量。细胞培养 毒性研究将确定生殖抑制是否是由于 多氯联苯或个别同系物对哺乳动物细胞的直接毒性作用。

In vivo and in vitro studies will evaluate the reproductive and fertility effects of two ubiquitous environmental contaminants, PCBs and DDE, on mammalian reproduction. Although use of these compounds were banned during the 1970's in the U.S., at present tissue levels of these two organochlorines in human and wildlife samples appear to have reached steady state. Transference of these compounds in utero across the placenta via the blood and from breast-feeding make the elimination of these exposure to new generations very unlikely in the short term. PCBs and DDE have been well studied individually, but little work has been done on possible synergistic effects on reproduction of these contaminants at environmentally-relevant levels of exposure. The present multigenerational investigation will utilize the native rodent Peromyscus polionotus as a model of assessment of risk to human as well as wildlife populations. Mated pairs will be exposured through the diet at the environmentally-relevant level of 5ppm PCBs (Aroclor 1254) and 5 ppm p,p' DDE individually in two groups of mice, while a third group will receive both contaminants. A control group will receive the same diet without PCBs or DDE. Offspring from the first generation of exposure will be paired with animals from the same regime to observe effects of two generations of exposure. Reproductive and fertility parameters including litter size, birth weight, survival to weaning and weaning weight will be measured in each of the two generations of mice investigated. Cell culture toxicity studies will determine if reproductive depression is due to direct toxic effects of PCBs or individual congeners on mammalian cells.