Division of Cell Sciences, Faculty of Veterinary Medicine, University of Glasgow, 464 Bearsden Road, Glasgow G61 1QH, Scotland, UK.
Gen Comp Endocrinol. 2010 Mar 1;166(1):25-32. doi: 10.1016/j.ygcen.2009.11.013. Epub 2009 Nov 20.
Unpredictable changes in the environment stimulate the avian hypothalamo-pituitary-adrenal axis to produce corticosterone, which induces behavioural and metabolic changes that enhance survival in the face of adverse environmental conditions. In addition to profound environmental perturbations, such as severe weather conditions and unpredictable food shortages, many Arctic-breeding birds are also confronted with chronic exposure to persistent organic pollutants (POPs), some of which are known to disrupt endocrine processes. This study investigated the adrenocortical function of a top predator in the Arctic marine environment, the glaucous gull (Larus hyperboreus). High concentrations of organochlorines, brominated flame retardants and metabolically-derived products in blood plasma of incubating glaucous gulls were associated with high baseline corticosterone concentrations in both sexes and a reduced stress response in males. Contaminant-related changes in corticosterone concentration occurred over and above differences in body condition and seasonal variation. Chronically high corticosterone concentrations and/or a compromised adrenocortical response to stress can have negative effects on the health of an individual. The results of the present study suggest that exposure to POPs may increase the vulnerability of glaucous gulls to environmental stressors and thus could potentially compromise their ability to adapt to the rapidly changing environmental conditions associated with climate change that are currently seen in the Arctic.
环境的不可预测变化会刺激禽类下丘脑-垂体-肾上腺轴产生皮质酮，从而引起行为和代谢变化，增强其在不利环境条件下的生存能力。除了严重的天气条件和不可预测的食物短缺等剧烈环境干扰外，许多北极繁殖鸟类还长期暴露于持久性有机污染物（POPs）中，其中一些已知会干扰内分泌过程。本研究调查了北极海洋环境中的顶级捕食者——北极鸥（Larus hyperboreus）的肾上腺皮质功能。孵卵北极鸥血液等离子体中高浓度的有机氯、溴化阻燃剂和代谢衍生产物与雌雄两性的基础皮质酮浓度升高以及雄性应激反应降低有关。皮质酮浓度的污染物相关变化超出了身体状况和季节性变化的差异。慢性高皮质酮浓度和/或肾上腺皮质对压力的反应受损可能对个体健康产生负面影响。本研究的结果表明，接触持久性有机污染物可能会增加北极鸥对环境胁迫的脆弱性，从而可能损害它们适应与气候变化相关的快速变化的环境条件的能力，而这种情况目前在北极地区已经出现。
