Partitioning of Polychlorinated Biphenyls into Human Cells and Adipose Tissues: Evaluation of Octanol, Triolein, and Liposomes as Surrogates

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• 作者：Cristina L. Quinn ; Stephan A. van der Heijden ; Frank Wania ; Michiel T. O. Jonker
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：May 20, 2014
• 年：2014
• 卷：48
• 期：10
• 页码：5920-5928
• 全文大小：370K
• 年卷期：v.48,no.10(May 20, 2014)
• ISSN：1520-5851

文摘

Whereas octanol, triacylglycerides, and liposomes have all been proposed as surrogates for measuring the affinity of hydrophobic organic contaminants to human lipids, no comparative evaluation of their suitability exists. Here we conducted batch sorption experiments with polyoxymethylene passive samplers to determine the partition coefficients at 37 掳C of 18 polychlorinated biphenyls (PCBs) from water into (i) triolein (K_{triolein/water}), (ii) eight types of liposomes (K_{liposome/water}), (iii) human abdominal fat tissues (K_AFT/water) from seven individuals, and (iv) human MCF-7 cells cultured in vitro (K_cell/water). Differences between K_AFT/water among individuals and between K_{liposome/water} among liposome types were very small and not correlated to structural attributes of the PCBs. Similarly, the length and degree of saturation of the phospholipid carbon chains, the headgroup, and the composition of the liposome did not affect the partitioning of PCBs into the studied liposomes. Whereas K_{liposome/water} values were similar to literature values of K_{octanol/water} adjusted to 37 掳C, they both were lower than K_AFT/water and K_cell/water by a factor of 3 on average. Partitioning of PCBs into triolein on the other hand closely mimicked that into human lipids, for which triolein is thus a better surrogate than either octanol or liposomes. Previously published polyparameter linear free energy relationships for partitioning from water into storage lipids and liposomes predicted the measured partition coefficients with a root-mean-square error of less than 0.15 log units, if the chosen equations and solute descriptors do not allow chlorine substitution in the ortho-position to influence the prediction. By guiding the selection of (i) a surrogate for the experimental determination and (ii) a method for the prediction of partitioning into human lipids, this study contributes to a better assessment of hydrophobic organic contaminant bioaccumulation in humans.