Sea Mammal Research Unit, Scottish Oceans Institute , University of St Andrews , St Andrews , Fife KY16 8LB , United Kingdom of Great Britain and Northern Ireland.
Louvain Institute of Biomolecular Science and Technology , Université Catholique de Louvain , Ottignies-Louvain-la-Neuve, Louvain-la-Neuve 1348 , Belgium.
Environ Sci Technol. 2018 Nov 20;52(22):13523-13534. doi: 10.1021/acs.est.8b04240. Epub 2018 Nov 2.
Persistent organic pollutants (POPs) are toxic, ubiquitous, resist breakdown, bioaccumulate in living tissue, and biomagnify in food webs. POPs can also alter energy balance in humans and wildlife. Marine mammals experience high POP concentrations, but consequences for their tissue metabolic characteristics are unknown. We used blubber explants from wild, gray seal ( Halichoerus grypus) pups to examine impacts of intrinsic tissue POP burden and acute experimental POP exposure on adipose metabolic characteristics. Glucose use, lactate production, and lipolytic rate differed between matched inner and outer blubber explants from the same individuals and between feeding and natural fasting. Glucose use decreased with blubber dioxin-like PCBs (DL-PCB) and increased with acute experimental POP exposure. Lactate production increased with DL-PCBs during feeding, but decreased with DL-PCBs during fasting. Lipolytic rate increased with blubber dichlorodiphenyltrichloroethane and its metabolites (DDX) in fasting animals, but declined with DDX when animals were feeding. Our data show that POP burdens are high enough in seal pups to alter adipose function early in life, when fat deposition and mobilization are vital. Such POP-induced alterations to adipose metabolic properties may significantly alter energy balance regulation in marine top predators, with the potential for long-term impacts on fitness and survival.
持久性有机污染物（POPs）是有毒的、普遍存在的、难以分解的，它们会在生物组织中积累，并在食物网中生物放大。POPs 还可以改变人类和野生动物的能量平衡。海洋哺乳动物经历着高浓度的 POP，但它们的组织代谢特征的后果尚不清楚。我们使用来自野生灰海豹（ Halichoerus grypus ）幼崽的皮下脂肪组织外植体，研究了内在组织 POP 负荷和急性实验性 POP 暴露对脂肪代谢特征的影响。来自同一个体的内层和外层皮下脂肪组织外植体之间以及摄食和自然禁食之间的葡萄糖利用、乳酸生成和脂肪分解率存在差异。葡萄糖利用随着皮下脂肪中二恶英类多氯联苯（DL-PCB）的增加而减少，随着急性实验性 POP 暴露的增加而减少。在摄食期间，乳酸生成随着 DL-PCBs 的增加而增加，但在禁食期间，乳酸生成随着 DL-PCBs 的增加而减少。在禁食动物中，脂肪分解率随着二氯二苯并对二恶英（DDX）及其代谢物的增加而增加，但当动物摄食时，脂肪分解率随着 DDX 的增加而减少。我们的数据表明，海豹幼崽体内的 POP 负荷足够高，以至于在生命早期就改变了脂肪的功能，此时脂肪的沉积和动员至关重要。这种 POP 诱导的脂肪代谢特性的改变可能会显著改变海洋顶级捕食者的能量平衡调节，从而对其适应性和生存能力产生长期影响。
