Organismal Biology and Ecology, University of Montana, Missoula, MT 59812, USA.
Gen Comp Endocrinol. 2010 Jan 15;165(2):345-50. doi: 10.1016/j.ygcen.2009.08.003. Epub 2009 Aug 15.
Changes in plasma corticosteroid-binding globulin (CBG) capacity can alter free plasma concentration and tissue availability of glucocorticoids (GC) and hence alter the organismal response to stress. However, CBG change in response to stress has not been extensively studied. While it is clear that chronic stress can causes CBG decline and in some species acute stressors can reduce CBG during the 30-60 min of the stressor, more long-term changes in CBG following an acute stressor has received less attention. Here we investigated corticosterone (CORT: the primary GC in birds) and CBG levels 24h after an acute stressor in a unique study system: Japanese quail divergently selected for CORT reactivity to acute stress. Using this model, we examined the interaction of selected CORT reactivity with CBG response to determine if CBG shows a delayed decline in response to an acute stressor and if that decline varies by selected genetic background. We found lowered CBG capacity, elevated total CORT and free CORT 24h after acute stress in all three quail groups. These results demonstrate for the first time in an avian species that exposure to an acute stressor can affect CBG and CORT 24h later.
血浆皮质类固醇结合球蛋白 (CBG) 容量的变化可改变糖皮质激素 (GC) 的游离血浆浓度和组织可用性，从而改变机体对压力的反应。然而，针对压力的 CBG 变化尚未得到广泛研究。虽然很明显慢性压力会导致 CBG 下降，而且在某些物种中，急性应激源在应激的 30-60 分钟内会降低 CBG，但人们对急性应激源后 CBG 的更长期变化关注较少。在这里，我们在一个独特的研究系统中研究了急性应激源后 24 小时皮质酮 (CORT：鸟类中的主要 GC) 和 CBG 水平：日本鹌鹑对急性应激的 CORT 反应性进行了差异选择。使用该模型，我们检查了所选 CORT 反应性与 CBG 反应的相互作用，以确定 CBG 是否对急性应激源表现出延迟下降，以及这种下降是否因所选遗传背景而异。我们发现，在所有三组鹌鹑中，急性应激后 24 小时 CBG 容量降低，总 CORT 和游离 CORT 升高。这些结果首次在鸟类中证明，暴露于急性应激源会在 24 小时后影响 CBG 和 CORT。
