Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Dr., Baton Rouge, LA 70803, USA.
Aquat Toxicol. 2010 Aug 15;99(2):300-8. doi: 10.1016/j.aquatox.2010.05.008. Epub 2010 May 24.
Fish bioaccumulate a variety of contaminants and act as an exposure portal to the human consumer. Surfactants, known pharmaceutically to alter membrane permeability, change drug bioavailability and attenuate transporter function are also found in contaminant mixtures in the aquatic environment. The overall objective of this study was to determine if the surfactant C-12 linear alkylbenzene sulfonate (LAS) at environmentally relevant concentrations, alters the disposition and enhances bioaccumulation of co-exposed dietary xenobiotics in the catfish. Included for study were the carcinogen benzo(a)pyrene (BaP), pharmaceutical, ivermectin (IVM), and P-glycoprotein (P-gp) substrate rhodamine 123 (Rho-123), each exhibiting different dispositional footprints. Rho-123 transport into bile and membrane fluidity was examined in isolated perfused livers from control and LAS exposed catfish. Mass balance residue assessments were performed on catfish following in vivo exposure for 12 days to LAS in water at 0, 100 or 300 microg/L with 6 days of (3)H-IVM or (3)H-BaP gavage treatments. LAS at 1, 5 and 20 microM in the perfused liver, significantly decreased the transport of Rho-123 (1 microM) into bile by 18.6, 38.1 and 66.7%, respectively. Fluorescence anisotropy measurements demonstrated a 29.7% increase in fluidity at the (1 microM, 348 microg/L) LAS concentration. In vivo mass balance studies indicated that waterborne LAS (100 and 300 microg/L) increased the dietary dose remaining in fish by 39% and 78% for (3)H-IVM and 50 and 157% for (3)H-BaP. LAS at environmentally relevant concentrations altered the bioavailability and disposition of dietary xenobiotics in the catfish. Co-exposure with LAS increases xenobiotic bioaccumulation, potential toxicity of mixture components to the fish and the potential for residue transfer from fish to the consumer.
鱼类会积累多种污染物，成为人类消费者暴露于污染物的门户。表面活性剂在水中的污染物混合物中也有发现，它们具有改变膜通透性的已知药物特性，改变药物生物利用度并减弱转运蛋白的功能。本研究的总体目标是确定环境相关浓度的表面活性剂 C-12 直链烷基苯磺酸盐（LAS）是否会改变共暴露于饮食性外源性化学物质的鲶鱼的处置方式并增强其生物积累。研究包括致癌物质苯并(a)芘（BaP）、药物伊维菌素（IVM）和 P-糖蛋白（P-gp）底物罗丹明 123（Rho-123），它们各自表现出不同的处置特征。在对照和 LAS 暴露的鲶鱼的离体灌注肝脏中，检查了 Rho-123 向胆汁的转运和膜流动性。在水中暴露于 0、100 或 300μg/L LAS 12 天后，对鲶鱼进行体内残留评估，并用 3H-IVM 或 3H-BaP 灌胃处理 6 天。在灌注肝脏中，1、5 和 20μM 的 LAS 分别使 Rho-123（1μM）向胆汁的转运减少了 18.6%、38.1%和 66.7%。荧光各向异性测量表明，在（1μM，348μg/L）LAS 浓度下，流动性增加了 29.7%。体内质量平衡研究表明，水相 LAS（100 和 300μg/L）使（3）H-IVM 的饮食剂量在鱼体内增加了 39%和 78%，（3）H-BaP 的饮食剂量增加了 50%和 157%。环境相关浓度的 LAS 改变了鲶鱼中饮食性外源性化学物质的生物利用度和处置方式。与 LAS 共同暴露会增加外源性化学物质的生物积累，混合物成分对鱼类的潜在毒性以及从鱼类向消费者转移残留物的潜力。
