College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China.
Shaanxi Institute of Zoology, Xi'an, 710032, China.
Ecotoxicol Environ Saf. 2020 Mar 1;190:110055. doi: 10.1016/j.ecoenv.2019.110055. Epub 2019 Dec 12.
Lead (Pb) is one of the most toxic metals to human and wildlife. It also had multiple negative influences on birds with physical, neurological and hematological clinical signs. However, the impacts of lead on bird liver lipid metabolism are still unclear. In this study, female Japanese quails were used to examine the effects of chronic lead exposure on liver histology, oxidative stress and AMPK (AMP-activated protein kinase) based lipid metabolism. Quails were randomly divided into 5 groups and each group was respectively fed with 0, 50, 250, 500 and 1000 ppm lead solution for 49 days. The result showed that exposure to 250, 500 and 1000 ppm Pb induced severe histopathological damages characterized by liver lipid vacuoles and accumulation, hepatic cytoplasmic hyalinization and vacuolization, hepatocytes necrosis, hepatic sinusoid congestion, and it also caused ultrastructural alterations featured by swelling and vacuolar mitochondria, the depolymerization of polyribosome, and lipid droplets accumulation. Moreover, significant decrease of activities of GPx (glutathione peroxidase), SOD (superoxide dismutase), CAT (catalase) and level of T-AOC (total antioxidant capacity) while significant increase of MDA (malondialdehyde) content were found in livers of all Pb groups. In addition, the expressions of genes related to fatty synthesis were significantly upregulated in livers of all Pb groups while the expressions of genes related to fatty β-oxidation were significantly downregulated in livers of 250 ppm Pb group. The present study indicated lead exposure does cause bird health damages through inducing liver microstructural and ultrastructural injury, oxidative damages and lipid metabolism disorder.
铅（Pb）是对人类和野生动物最具毒性的金属之一。它还对鸟类产生了多种负面影响，表现为身体、神经和血液学临床症状。然而，铅对鸟类肝脏脂质代谢的影响尚不清楚。在这项研究中，使用雌性日本鹌鹑来检验慢性铅暴露对肝脏组织学、氧化应激和基于 AMPK（AMP 激活蛋白激酶）的脂质代谢的影响。鹌鹑被随机分为 5 组，每组分别喂食 0、50、250、500 和 1000ppm 的铅溶液，持续 49 天。结果表明，暴露于 250、500 和 1000ppm 的 Pb 会引起严重的组织病理学损伤，特征为肝脂质空泡和积累、肝细胞质玻璃样变和空泡化、肝细胞坏死、肝窦充血，并且还会导致超微结构改变，特征为肿胀和空泡化的线粒体、多核糖体的解聚以及脂质滴的积累。此外，所有 Pb 组的肝脏中 GPx（谷胱甘肽过氧化物酶）、SOD（超氧化物歧化酶）、CAT（过氧化氢酶）的活性显著降低，T-AOC（总抗氧化能力）水平显著降低，而 MDA（丙二醛）含量显著升高。此外，所有 Pb 组的肝脏中与脂肪酸合成相关的基因表达显著上调，而 250ppm Pb 组的肝脏中与脂肪酸β-氧化相关的基因表达显著下调。本研究表明，铅暴露通过诱导肝脏微观和超微结构损伤、氧化损伤和脂质代谢紊乱对鸟类健康造成损害。
