Effect of voluntary wheel running on circadian corticosterone release and on HPA axis responsiveness to restraint stress in Sprague-Dawley rats
Effect of voluntary wheel running on circadian corticosterone release and on HPA axis responsiveness to restraint stress in Sprague-Dawley rats
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DOI：
10.1152/japplphysiol.01416.2005
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发表时间：
2006-06-01
影响因子：
3.3
通讯作者：
Riddell, Michael C.
中科院分区：
文献类型：
--
作者：
Fediuc, Sergiu;Campbell, Jonathan E.;Riddell, Michael C.
放大图片作者：Jonathan E.坎贝尔和迈克尔C.里德尔。自愿轮跑对Sprague-道利大鼠昼夜皮质酮释放和HPA轴对束缚应激反应性的影响。J Appl Physiol 100：1867 - 1875，2006.首次发表于2006年1月26日; doi：10.1152/japplphysiol. 01416.2005. - 下丘脑-垂体-肾上腺（HPA）轴对啮齿类动物自愿运动的适应尚不清楚，因为大多数研究使用与心理应激相关的强迫运动方案。在本研究中，我们研究了自愿轮运行的昼夜皮质酮（Cort）的节奏，以及HPA轴的反应，并恢复，约束压力的影响。雄性Sprague-Dawley大鼠分为运动组（E）和安静组（S），E组大鼠连续5 wk进行24 h的转轮运动。在每周结束时测量昼夜血浆Cort水平，除了第5周，当大鼠暴露于20分钟的束缚应激，然后是95分钟的恢复。在限制方案结束时，使用Western印迹法测量海马和垂体前叶中糖皮质激素受体的含量。在第1周，E组的昼夜Cort水平是S组动物的两倍，但在整个训练方案中，E组的水平逐渐降低，到第4周时达到S组观察到的相似值。在束缚应激和恢复期间，E和S之间的Cort值相似，死亡后海马和脑垂体中的糖皮质激素受体含量也相似。与E组相比，S组动物在束缚期间血浆ACTH水平较高。总之，这些数据表明，5周的轮运行与正常的昼夜Cort活动和正常的负反馈抑制HPA轴，以及与肾上腺皮质激素的敏感性增加后约束应力。
Fediuc, Sergiu, Jonathan E. Campbell, and Michael C. Riddell. Effect of voluntary wheel running on circadian corticosterone release and on HPA axis responsiveness to restraint stress in Sprague- Dawley rats. J Appl Physiol 100: 1867 - 1875, 2006. First published January 26, 2006; doi: 10.1152/japplphysiol. 01416.2005. - Adaptations of the hypothalamic-pituitary-adrenal (HPA) axis to voluntary exercise in rodents are not clear, because most investigations use forced-exercise protocols, which are associated with psychological stress. In the present study, we examined the effects of voluntary wheel running on the circadian corticosterone (Cort) rhythm as well as HPA axis responsiveness to, and recovery from, restraint stress. Male Sprague-Dawley rats were divided into exercise (E) and sedentary (S) groups, with E rats having 24-h access to running wheels for 5 wk. Circadian plasma Cort levels were measured at the end of each week, except for week 5 when rats were exposed to 20 min of restraint stress, followed by 95 min of recovery. Measurements of glucocorticoid receptor content in the hippocampus and anterior pituitary were performed using Western blotting at the termination of the restraint protocol. In week 1, circadian Cort levels were twofold higher in E compared with S animals, but the levels progressively decreased in the E group throughout the training protocol to reach similar values observed in S by week 4. During restraint stress and recovery, Cort values were similar between E and S, as was glucocorticoid receptor content in the hippocampus and pituitary gland after death. Compared with E, S animals had higher plasma ACTH levels during restraint. Taken together, these data indicate that 5 wk of wheel running are associated with normal circadian Cort activity and normal negative-feedback inhibition of the HPA axis, as well as with increased adrenal sensitivity to ACTH after restraint stress.