Glucocorticosteroid concentrations in feces and hair of captive caribou and reindeer following adrenocorticotropic hormone challenge
Glucocorticosteroid concentrations in feces and hair of captive caribou and reindeer following adrenocorticotropic hormone challenge
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DOI：
10.1016/j.ygcen.2011.03.029
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发表时间：
2011-07-01
影响因子：
2.7
通讯作者：
Wasser, S. K.
中科院分区：
文献类型：
--
作者：
Ashley, N. T.;Barboza, P. S.;Wasser, S. K.
气候变化和工业发展正在导致整个北极地区的游骑兵数量同步下降。慢性应激被认为是与自由放养种群减少相关的直接因素，但其在放养动物中的作用尚不清楚。分析粪便中的糖皮质激素 (GC) 浓度，以及最近分析头发中的糖皮质激素 (GC) 浓度，是一种监测野生动物压力的非侵入性方法。垂体释放的促肾上腺皮质激素 (ACTH) 会刺激肾上腺释放 GC，并且可以通过施用来反映肾上腺的激活情况。在这项研究中，我们评估了接受 ACTH 治疗后阿拉斯加驯鹿 (Rangifer tarandus granti) 和驯鹿 (R. t. tarandus) 粪便中 GC 代谢物和毛发中皮质醇的浓度。我们预测 ACTH 挑战会增加粪便 GC 的浓度，但不会增加头发皮质醇的浓度，因为沉积到毛干的类固醇会在很长一段时间内（数月）发生，并且可能对急性肾上腺刺激不敏感。与注射前浓度相比，成年驯鹿（n = 10；平均年龄为 6.5 岁）在注射 2 IU/kg 剂量的 ACTH 后 8 小时，粪便 GC 出现峰值增加。相比之下，亚成年驯鹿（n = 10，0.8 岁）对相同剂量的反应减弱。将剂量增加四倍（8 IU/kg）可延长雌性驯鹿的粪便GC反应，但雄性驯鹿没有反应。头发皮质醇不受单一 ACTH 挑战的影响。需要进一步调查以确定肾上腺敏感性的亚特异性差异是否归因于年龄或性别差异，或驯鹿半驯化和/或久坐生命周期的历史选择压力。 (C) 2011 Elsevier Inc. 保留所有权利。
Climate change and industrial development are contributing to synchronous declines in Rangifer populations across the Arctic. Chronic stress has been implicated as a proximate factor associated with decline in free-ranging populations, but its role in Rangifer is unspecified. Analysis of glucocorticosteroid (GC) concentration in feces, and more recently in hair, is a non-invasive method for monitoring stress in wildlife. Adrenocorticotropic hormone (ACTH) released from the pituitary gland stimulates GC release from the adrenals and can be administered to reflect adrenal activation. In this study, we assessed concentrations of GC metabolites in feces and cortisol in hair of Alaskan caribou (Rangifer tarandus granti) and reindeer (R. t. tarandus) following ACTH treatment. We predicted that ACTH challenge would increase concentrations of fecal GCs, but not hair cortisol because steroid deposited into the hair shaft occurs over an extended period of time (months) and is likely insensitive to acute adrenal stimulation. Adult caribou (n = 10; mean age, 6.5 years old) exhibited a peak increase in fecal GCs 8 h following a 2 IU/kg dose of ACTH compared to pre-injection concentrations. In contrast, sub-adult reindeer (n = 10, 0.8 years old) elicited a diminished response to the same dose. Quadrupling the dose (8 IU/kg) prolonged the fecal GC response in female reindeer, but male reindeer were unresponsive. Hair cortisol was unaffected by a single ACTH challenge. Further investigation is required to ascertain whether subspecific differences in adrenal sensitivity are attributed to age or sex differences, or historical selective pressures from semi-domestication and/or sedentary life cycle in reindeer. (C) 2011 Elsevier Inc. All rights reserved.