Graduate School of Oceanography, University of Rhode Island, 218 South Ferry Rd, Narragansett, RI 02882, USA.
Comp Biochem Physiol C Toxicol Pharmacol. 2010 Jun;152(1):9-17. doi: 10.1016/j.cbpc.2010.02.006. Epub 2010 Feb 16.
Little is known about the sensitivity of teleost post-embryonic developmental stages (larval and metamorphic) to dioxin-like compounds. Larval and metamorphosing summer flounder (Paralichthys dentatus) were exposed to the dioxin-like polychlorinated biphenyl congener PCB 126, to compare their sensitivity to other fish species early life stages, and to document effects on metamorphic development, including degree of eye migration and gastric maturation. Median lethal doses (LD 50s) ranged between 30 and 220 ng/g wet mass, indicating that pre- and early-metamorphic stages of summer flounder are equally sensitive to the embryos of some of the most vulnerable fish species tested. Consistent with the presence of a functional aryl hydrocarbon receptor pathway, dose-dependent induction of cytochrome P-4501A (CYP1A) at four days post-exposure was observed in liver, stomach, intestine, and kidney of metamorphosing larvae. Stage-dependent differences in the epithelial distribution of CYP1A immunoreactivity were observed in the developing stomach of fish exposed to relatively high PCB 126 doses. A single sublethal dose (15 ng/g) delayed metamorphic progress (determined by the degree of eye migration), and resulted in abnormally high levels of cell proliferation and abnormal gastric gland morphology in late metamorphic stages. These results suggest that the post-embryonic larval and metamorphic stages of summer flounder, and potentially other fish species with complex life histories, are vulnerable to the effects of dioxin-like compounds, including lethality, developmental delay, and malformations.
关于后生鱼类（幼鱼和成鱼）阶段对二恶英样化合物的敏感性知之甚少。我们用二恶英样多氯联苯同系物 PCB 126 来暴露幼鱼和成鱼，来比较它们对其他鱼类早期生命阶段的敏感性，并记录对变态发育的影响，包括眼睛迁移和胃成熟的程度。半数致死剂量（LD50s）范围在 30 到 220ng/g 湿重之间，这表明在夏季比目鱼的预变态和早期变态阶段对一些最脆弱的鱼类胚胎同样敏感。与芳基烃受体途径的存在一致，在暴露后第四天，在肝脏、胃、肠和肾脏中观察到细胞色素 P-4501A（CYP1A）的剂量依赖性诱导。在暴露于相对高剂量 PCB 126 的鱼的发育胃中，观察到 CYP1A 免疫反应性的上皮分布存在与阶段相关的差异。单次亚致死剂量（15ng/g）延迟了变态发育（通过眼睛迁移的程度来确定），并导致晚期变态阶段细胞增殖异常和异常的胃腺形态。这些结果表明，夏季比目鱼的后生幼鱼和变态阶段，以及其他具有复杂生活史的鱼类，可能容易受到二恶英样化合物的影响，包括致死、发育迟缓和畸形。
