胚胎期和哺乳期全氟辛烷磺酸(PFOS)暴露致大鼠学习记忆能力下降

为了探讨全氟辛烷磺酸(PFOS)的发育神经毒性，寻找PFOS发育神经毒性作用的敏感期，利用水迷宫和组织病理切片技术，研究了胚胎期和哺乳期暴露于PFOS后新生大鼠发育情况、学习记忆能力、抓力以及海马组织病理学改变。结果显示：PFOS导致仔鼠发育迟缓，睁眼期延迟。仔鼠出生后体重与对照组相比出现显著性降低。同一PFOS暴露浓度下，胚胎期暴露组体重低于哺乳期暴露组，抓力差异不显著。水迷宫实验结果显示，TT15(胚胎期和哺乳期均暴露于15 mg·L^-1 PFOS)和TC15(仅胚胎期暴露于15 mg·L^-1 PFOS)暴露组仔鼠逃避潜伏期显著高于对照组，且TC15暴露组仔鼠逃避潜伏期显著性高于CT15(仅哺乳期暴露于15 mg·L^-1 PFOS)暴露组。空间探索实验中，TT15暴露组仔鼠在目标象限的游泳时间显著性低于对照组，其他组无显著性差异。组织病理切片结果显示暴露组海马组织细胞数量减少，出现细胞凋亡现象。结果表明，PFOS造成仔鼠的发育延迟以及学习记忆能力下降的关键作用时期可能是胚胎期。     

Distribution of perfluorochemicals between sera and milk from the same mothers and implications for prenatal and postnatal exposures

The levels of six perfluorocarboxylates (PFCAs), four perfloroalkylsulfonates (PFASs), and one sulfonamide were measured in paired samples of maternal serum, umbilical cord serum, and breast milk. The maternal and cord sera were strongly correlated with each other for all measured compounds (r > 0.5 and p < 0.01). Nevertheless, there was a significant difference in compound composition profile between the two sera matrices, with a more depletion of the longer chain compounds in cord serum. The transfer efficiency values from maternal to cord serum (TF_CS/MS) decreased by 70% with each increasing unit of -CF₂ chain within a PFCA group, and for perfluorooctanesulfonate (PFOS), by a half compared to perfluorooctanoate (PFOA). In contrast to the strong correlation in concentrations between the two sera matrices, the pattern of compounds in breast milk differed considerably with those in sera. Accordingly, compound- and matrix-specific transfer must be considered when assessing prenatal and postnatal exposure.