Seasonal glucocorticoid responses to capture in wild free-living mammals.
Seasonal glucocorticoid responses to capture in wild free-living mammals.
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DOI：
10.1152/ajpregu.00752.2007
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发表时间：
2008-02
期刊：
影响因子：
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通讯作者：
L. Romero;Cecile J Meister;Nicole E. Cyr;G. Kenagy;J. Wingfield;Romero Lm;Meister Cj;Cyr Ne;Kenagy Gj;J. Wingfield;Sea;L. Romero
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文献类型：
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作者：
L. Romero;Cecile J Meister;Nicole E. Cyr;G. Kenagy;J. Wingfield;Romero Lm;Meister Cj;Cyr Ne;Kenagy Gj;J. Wingfield;Sea;L. Romero
我们确定了基线和捕获诱导的糖皮质激素浓度在两个不同的季节在三个物种的野生自由生活的啮齿动物：棕色旅鼠（Lemmus trimucronatus），金色的地松鼠（黄鼠saturatus），和黄松花鼠（Tamias amoenus）。在捕获后3分钟内获得初始血样，以使初始糖皮质激素水平反映未受干扰动物的基线滴度。再将动物保持30分钟，然后采集第二份血样以测量应激诱导的糖皮质激素滴度。主要的糖皮质激素在每个物种中不同。旅鼠分泌大量的皮质酮（高达8,000 ng/ml）。这些高浓度伴随着高皮质酮结合球蛋白的能力和抗负反馈。松鼠和花栗鼠分泌皮质醇和皮质酮的混合物（10-400 ng/ml）。在所有三个物种的男性和女性松鼠和花栗鼠，糖皮质激素水平显着升高30分钟后捕获。每个物种的基线和30分钟糖皮质激素水平季节性不同。水平较高，在夏季（无积雪）比春季（约60%的积雪），在雌性旅鼠，在繁殖期间高于冬眠前的松鼠，并高于繁殖后比在花栗鼠繁殖。总之，这些数据表明，在这些自由生活的物种的糖皮质激素反应的压力是类似的实验室物种，但反应的幅度似乎取决于特定于每个物种的生活史功能。
We determined baseline and capture-induced glucocorticoid concentrations during two different seasons in three species of wild free-living rodents: brown lemmings (Lemmus trimucronatus), golden-mantled ground squirrels (Spermophilus saturatus), and yellow-pine chipmunks (Tamias amoenus). Initial blood samples were obtained within 3 min of capture, so that initial glucocorticoid levels reflect baseline titers of undisturbed animals. Animals were held for an additional 30 min, when a second blood sample was taken to measure stress-induced glucocorticoid titers. The primary glucocorticoid differed in each species. Lemmings secreted extremely large amounts of corticosterone (as high as 8,000 ng/ml). These high concentrations were accompanied by high corticosterone-binding globulin capacity and resistance to negative feedback. Squirrels and chipmunks secreted a mixture of cortisol and corticosterone (10-400 ng/ml). In males of all three species and female squirrels and chipmunks, glucocorticoid levels were significantly elevated 30 min after capture. Baseline and 30-min glucocorticoid levels differed seasonally in each species. Levels were higher during summer (with no snow cover) than in spring (with approximately 60% snow cover) in female lemmings, higher during breeding than before hibernation in squirrels, and higher postreproductively than during breeding in chipmunks. Together, these data indicate that glucocorticoid responses to stress in these free-living species are similar to those in laboratory species, but the magnitude of the response appears to depend on life-history features specific to each species.