Changes in adrenal capacity contribute to a decline in the stress response with age in a long-lived seabird
Changes in adrenal capacity contribute to a decline in the stress response with age in a long-lived seabird
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DOI：
10.1016/j.ygcen.2008.02.014
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发表时间：
2008-05-01
影响因子：
2.7
通讯作者：
Ketterson, Ellen D.
中科院分区：
文献类型：
--
作者：
Heidinger, Britt J.;Nisbet, Ian C. T.;Ketterson, Ellen D.
为了应对应激源，大多数脊椎动物会增加糖皮质激素（CORT）的分泌，以产生“应激反应”，从而提高生存率，但同时抑制繁殖。当前繁殖价值相对于未来繁殖和生存价值较高的情况通常会导致应激反应的抑制，从而确保关键资源不会从繁殖中转移。与这一预期一致，我们之前曾报道过，在长寿海鸟——普通燕鸥（Sterna hirundo）的繁殖成体中，应激反应的强度（CORT 的最大水平）随着年龄的增长而下降。虽然与年龄相关的应激反应变化在脊椎动物中可能很常见，但人们对其背后的机制却知之甚少。糖皮质激素应激反应受下丘脑-垂体-肾上腺 (HPA) 轴调节，可能导致应激反应与年龄相关的下降的一种机制是肾上腺功能的变化（肾上腺对 ACTH 的敏感性和/或响应 ACTH 分泌 CORT 的能力）。为了检验这一假设，我们捕获了 92 只已知年龄的成年普通燕鸥（Sterna hirundo），年龄从 3 岁到 29 岁不等，并注射了对照盐水或实验性促肾上腺皮质激素 (ACTH) 溶液，并测量了约束 30 分钟后对应激诱导的 CORT 的影响。在两个治疗组中，压力诱导的 CORT 随着年龄的增长而显着下降，这表明肾上腺功能的下降有助于减少老年人的压力反应。 (c) 2008 Elsevier Inc. 保留所有权利。
In response to stressors, most vertebrates elevate secretion of glucocorticoids (CORT) to produce a 'stress response' that enhances survival, but simultaneously inhibits reproduction. Circumstances in which the value of current reproduction is high relative to the value of future reproduction and survival, often lead to suppression of the stress response thus ensuring that critical resources are not diverted away from reproduction. Consistent with this expectation, we have previously reported that the magnitude of the stress response (maximum levels of CORT) declines with age in breeding adults of a long-lived seabird, the common tern (Sterna hirundo). While age-related changes in the stress response may be common in vertebrates, the mechanisms that underlie them are poorly understood. The glucocorticoid stress response is regulated by the hypothalamic-pituitary-adrenal (HPA) axis, and one mechanism that may contribute to an age-related decline in the stress response is changes in adrenal capacity (adrenal sensitivity to ACTH and/or an ability to secrete CORT in response to ACTH). To test this hypothesis, we captured and injected 92 known-aged adult common terns(Sterna hirundo) ranging in age from 3 to 29 years with either a control saline or an experimental adrenocorticotropin (ACTH) solution and measured the effects on stress-induced CORT after 30 min of restraint. In both treatment groups, stress-induced CORT significantly declined with age, suggesting that a decrease in adrenal capacity contributes to a reduction in the stress response in older adults. (c) 2008 Elsevier Inc. All rights reserved.