Distinct, time-dependent effects of voluntary exercise on circadian and ultradian rhythms and stress responses of free corticosterone in the rat hippocampus.
Distinct, time-dependent effects of voluntary exercise on circadian and ultradian rhythms and stress responses of free corticosterone in the rat hippocampus.
复制标题
DOI：
10.1210/en.2009-0402
复制
发表时间：
2009-09
期刊：
影响因子：
4.8
通讯作者：
Reul JM
中科院分区：
文献类型：
--
作者：
Droste SK;Collins A;Lightman SL;Linthorst AC;Reul JM
先前的研究表明，让大鼠自愿在转轮中运动4周，可以改变下丘脑-垂体-肾上腺轴和对压力的行为应对反应。为了研究长期自愿运动是否也会影响大脑中皮质酮的游离生物活性部分，我们在大鼠海马中进行了体内微透析研究。我们监测的基线昼夜节律和超昼夜模式的皮质酮在海马透析液在昼夜周期和强迫游泳和新奇的压力在不同阶段的运动的反应。运动1天，2天，或1周没有影响基线昼夜节律和超昼夜脉冲参数或应激诱导的海马游离皮质酮浓度表明，急性或短期的运动不影响基线和应激诱导的激素水平。然而，4周运动大鼠的基线激素参数显示，在1500和2100 h之间脉冲幅度（+108%）和平均游离皮质酮水平（+42%）显著增加，但在0900和1500 h之间没有增加。令人惊讶的是，虽然我们以前的工作表明，在长期运动的动物应激诱发的血浆（总）皮质酮反应的实质性变化，应激诱导的海马游离激素反应没有差异，可以观察到运动和久坐的动物之间。这种差异的缺乏不是由运动大鼠血浆皮质类固醇结合球蛋白结合水平的代偿性变化引起的。因此，长期运动的大鼠在活跃期开始之前表现出糖皮质激素输出的预期增加。这些大鼠还揭示了一种遏制机制的假定存在，防止大脑过度分泌糖皮质激素。
Previous work has shown that allowing rats to voluntarily exercise in a running wheel for 4 wk modifies the hypothalamic-pituitary-adrenal axis and behavioral coping responses to stress. To investigate whether long-term voluntary exercise would also affect the free, biologically active fraction of corticosterone in the brain, we conducted an in vivo microdialysis study in the hippocampus of rats. We monitored both the baseline circadian and ultradian patterns of corticosterone in hippocampus dialysates over the diurnal cycle and the responses to forced swim and novelty stress at different stages of exercise. Exercise for 1 d, 2 d, or 1 wk did not affect baseline circadian and ultradian pulse parameters or stress-induced hippocampal free corticosterone concentrations suggesting that acute or short-term periods of exercise do not affect baseline and stress-induced hormone levels. Baseline hormone parameters in 4 wk exercised rats, however, showed significantly increased pulse amplitudes (+108%) and mean free corticosterone levels (+42%) between 1500 and 2100 h but not between 0900 and 1500 h. Surprisingly, although our previous work showed substantial changes in stress-evoked plasma (total) corticosterone responses in long-term exercised animals, no differences in stress-induced hippocampal free hormone responses could be observed between exercised and sedentary animals. This lack of differences was not caused by compensatory changes in plasma corticosteroid-binding-globulin binding levels in exercising rats. Thus, long-term exercising rats show anticipatory increases in glucocorticoid output before the start of the active phase. These rats also reveal the putative existence of a containment mechanism preventing overexposure of the brain to glucocorticoid hormones.
登录
查看更多内容
影响因子：
4.7
作者：
Chandramohan, Yalini;Droste, Susanne K.;Reul, Johannes M. H. M.
通讯作者：
Reul, Johannes M. H. M.
影响因子：
3.7
作者：
Collins A;Hill LE;Chandramohan Y;Whitcomb D;Droste SK;Reul JM
通讯作者：
Reul JM
影响因子：
3.3
作者：
de Groote, L.;Linthorst, A. C. E.
通讯作者：
Linthorst, A. C. E.
影响因子：
3.2
作者：
Droste, S. K.;Schweizer, M. C.;Reul, J. M. H. M.
通讯作者：
Reul, J. M. H. M.
影响因子：
3.3
作者：
Coutinho, AE;Campbell, JE;Riddell, MC
通讯作者：
Riddell, MC