Data from: Corticosterone: effects on feather quality and deposition into feathers

1. The concentration of the glucocorticoid hormone corticosterone (CORT) is increasingly used in ecology and conservation biology as an integrated measure of the historical record of an individual's hypothalamo-pituitary-adrenal (HPA) activity during feather growth. However, where and how CORT is incorporated in feathers is incompletely known. 2. We therefore examined whether CORT is reliably measured with an enzyme immunoassay, where CORT is incorporated in the feather and where it affects feather quality, and whether CORT incorporation is related to plasma CORT levels, feather growth rate and melanin pigmentation. 3. During regrowth of plucked tail feathers, we injected pigeons with tritium-labelled CORT, and implanted a CORT-releasing pellet to increase plasma CORT concentration for about three days. In feather segments we measured labelled CORT (DPM3H) and we quantified CORT with an enzyme immunoassay EIA (CORTEIA) and double-checked the results with ultra-high performance liquid chromatography-tandem mass spectrometry (LCMS) (CORTMS). 4. Administered CORT affected feather structure and colour at the very base of the feather (epidermal collar, ramogenic zone) and reduced growth rate. In contrast, incorporation of CORT into the feather happened mainly in the blood quill, as shown with all three methods (DPM3H, CORTEIA, and CORTMS). 5. Incorporation of CORT into feathers was only roughly proportional to plasma concentration, proportional to feather-growth rate and increased with melanin pigmentation. 6. Measuring CORT in feather is a way to reveal past events of increased stress during feather growth in birds.

1. 糖皮质激素皮质酮（corticosterone, CORT）的浓度，作为个体在羽毛生长期间下丘脑-垂体-肾上腺（hypothalamo-pituitary-adrenal, HPA）活动历史记录的整合性指标，正日益广泛应用于生态学与保护生物学领域。但目前学界对皮质酮如何掺入羽毛以及掺入的具体部位仍不完全明确。
2. 因此本研究旨在探究以下问题：酶免疫测定法能否可靠检测皮质酮含量、皮质酮在羽毛中的掺入部位及其对羽毛质量的影响，以及皮质酮的掺入是否与血浆皮质酮水平、羽毛生长速率及黑色素沉着程度相关。
3. 本研究在拔取尾羽后的再生过程中，对家鸽注射氚标记的皮质酮，并植入皮质酮缓释颗粒以提升血浆皮质酮浓度约3天。我们在不同羽毛节段中检测了氚标记皮质酮的放射性计数（DPM³H），同时采用酶免疫测定法（enzyme immunoassay, EIA，即CORTEIA）定量皮质酮，并通过超高效液相色谱-串联质谱（ultra-high performance liquid chromatography-tandem mass spectrometry, LCMS，即CORTMS）对结果进行了双重验证。
4. 外源性施加的皮质酮会在羽毛基部（表皮领、羽枝发生区）影响羽毛结构与色泽，并降低羽毛生长速率。与之相反，三种检测方法（DPM³H、CORTEIA及CORTMS）均显示，皮质酮向羽毛内的掺入主要发生在血羽管阶段。
5. 羽毛内皮质酮的掺入量仅与血浆浓度大致呈正比，同时与羽毛生长速率呈正相关，并随黑色素沉着程度升高而增加。
6. 通过检测羽毛中的皮质酮含量，可揭示鸟类在羽毛生长期间曾经历的应激水平升高的过往事件。