Knowledge on species' reproductive biology is a fundamental pre-requisite of every conservation effort, but is often lacking. Sex steroids can provide valuable information for the assessment of reproductive success, whereas glucocorticoids are used to assess adrenocortical activity and stress-related bodily adaption. However, due to their perilous condition, access to animals is often difficult, which makes hormone measurement in non-invasively collected hair samples an attractive option. We determined cortisol, cortisone, corticosterone, testosterone and progesterone in Iberian lynx hair using enzyme immunoassay (EIA). Cross-validation was performed with high-performance liquid chromatography (HPLC) and high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Finally, we statistically evaluated the variations of sex steroids and glucocorticoids according to age, sex, origin, behavior and management. All steroids except corticosterone were detectable in Iberian lynx hair. Hair progesterone measured by EIA was overestimated by cross-reaction with 5α-dihydroprogesterone, a biologically active gestagene, and was highly correlated with HPLC-MS/MS results. Progesterone was higher in adult females compared to all other age-sex groups. Cortisol measured by EIA was overestimated due to antibody cross-reactivity with cortisone and was correlated to the sum of HPLC-MS/MS measurements for cortisol and cortisone. Cortisol was higher in females than in males measured by HPLC-MS/MS, but the EIA results were confounded by the lack of specificity. When using cortisol-cortisone and cortisol-dihydroepiandrosterone ratios, differences were noted between wild-caught and captive-bred lynxes. Additionally, longitudinal EIA measurements of an Iberian lynx after a wildfire showed an inversion of the cortisol-cortisone ratio that later subsided. These results validate the use of hair progesterone measurement for Iberian lynx reproductive monitoring and add to the growing evidence supporting the need for a more comprehensive approach to hair steroid measurement that accounts for local interconversion and co-regulation mechanisms.

中文翻译：

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伊比利亚猫性发中的性类固醇和糖皮质激素比率。

有关物种生殖生物学的知识是每次保护工作的基本先决条件，但往往缺乏。性类固醇可以为评估生殖成功提供有价值的信息，而糖皮质激素则用于评估肾上腺皮质活动和与压力相关的身​​体适应能力。但是，由于它们处于危险状态，接触动物通常很困难，这使得在非侵入式采集的头发样本中进行激素测量成为一种有吸引力的选择。我们使用酶免疫法（EIA）测定了伊比利亚ian猫毛中的皮质醇，可的松，皮质酮，睾丸激素和孕酮。使用高效液相色谱（HPLC）和高效液相色谱与串联质谱联用（HPLC-MS / MS）进行交叉验证。最后，我们根据年龄，性别，出身，行为和管理，对性类固醇和糖皮质激素的变化进行了统计评估。除皮质酮外，所有类固醇都可在伊比利亚猫的头发中检出。与具有生物活性的孕激素5α-二氢孕酮发生交叉反应，高估了EIA测量的头发孕酮，并与HPLC-MS / MS结果高度相关。与所有其他年龄组相比，成年女性的孕酮水平更高。由于抗体与可的松的交叉反应性，EIA测量的皮质醇被高估了，并且与皮质醇和可的松的HPLC-MS / MS测量值之和相关。通过HPLC-MS / MS测定，女性的皮质醇水平高于男性，但EIA结果因缺乏特异性而混淆。当使用皮质醇-可的松和皮质醇-二氢表雄酮的比例时，注意到野生捕获的天猫和圈养的天猫之间存在差异。此外，野火后伊比利亚山猫的纵向EIA测量显示，皮质醇-可的松比例倒置，随后消失。这些结果验证了将头发孕酮测量用于伊比利亚天猫繁殖监测，并增加了越来越多的证据，支持需要一种更全面的方法来测量头发类固醇，该方法应考虑局部的相互转换和共调节机制。