Drouillard K G, Fernie K J, Smits J E, Bortolotti G R, Bird D M, Norstrom R J
Watershed Ecosystems Program, Trent University, Peterborough, Ontario, Canada.
Environ Toxicol Chem. 2001 Nov;20(11):2514-22.
The bioaccumulation and toxicokinetics of 42 polychlorinated biphenyls (PCBs) was determined in male American kestrels exposed to an Aroclor-contaminated diet for 120 d followed by a 348-d depuration period. The birds were housed under ambient outdoor temperatures to permit normal fluctuations in body weight during the study. Whole body PCB clearance, plasma/fat distribution coefficients, and plasma PCB clearance constants were determined for individual PCBs to calibrate a two-compartment rate constant model in order to describe PCB elimination in the birds. Plasma/fat partition coefficients (K(PF)) averaged 0.0060 +/- 0.0001 for all congeners of study, were not dependent on chemical hydrophobicity, and did not change in summer versus winter sacrificed animals. Plasma clearance constants (k'pc) for PCBs were observed to be dependent on both chlorine substitution patterns and congener hydrophobicity. Polychlorinated biphenyl congeners categorized as readily cleared congeners contained vicinal meta-para hydrogen substituents on at least one phenyl ring, while slowly cleared congeners were chlorine hindered at these positions. A general equation was derived to predict plasma clearance constants for all tri- to octachlorobiphenyls based on the presence of an open meta-para site on one of the phenyl rings and from the n-octanol-water partition coefficient of the chemical. The equation was validated by comparing predicted versus measured relative biomagnification factors of PCBs determined in birds at the end of the dosing period. The two-compartment model calibrated for PCB elimination in American kestrels may be used to describe PCB toxicokinetics in wild birds provided that seasonal fluctuations in the fat content of the modeled population is known.
在暴露于含多氯联苯混合物（Aroclor）污染饲料120天，随后经历348天净化期的雄性美洲隼中，测定了42种多氯联苯（PCBs）的生物累积和毒代动力学。在研究期间，将这些鸟饲养在室外环境温度下，以允许体重正常波动。测定了个体多氯联苯的全身多氯联苯清除率、血浆/脂肪分配系数和血浆多氯联苯清除常数，以校准一个二室速率常数模型，以便描述鸟类体内多氯联苯的消除情况。所有研究同系物的血浆/脂肪分配系数（K(PF)）平均为0.0060±0.0001，不依赖于化学疏水性，并且在夏季与冬季处杀的动物中没有变化。观察到多氯联苯的血浆清除常数（k'pc）既依赖于氯取代模式，也依赖于同系物的疏水性。归类为易清除同系物的多氯联苯同系物在至少一个苯环上含有邻位间位-对位氢取代基，而清除缓慢同系物在这些位置被氯阻碍。基于其中一个苯环上存在开放的间位-对位位点以及化学物质的正辛醇-水分配系数，推导了一个通用方程来预测所有三至八氯联苯的血浆清除常数。通过比较给药期结束时在鸟类中测定的多氯联苯预测与实测相对生物放大因子，验证了该方程。为描述美洲隼体内多氯联苯消除而校准的二室模型，可用于描述野生鸟类中的多氯联苯毒代动力学，前提是已知建模群体脂肪含量的季节性波动情况。
