A long-term increase in basal levels of corticosterone and a decrease in corticosteroid-binding globulin after acute stressor exposure.
A long-term increase in basal levels of corticosterone and a decrease in corticosteroid-binding globulin after acute stressor exposure.
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DOI：
10.1210/endo.136.12.7588279
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发表时间：
1995-12
期刊：
影响因子：
4.8
通讯作者：
M. Fleshner;T. Deak;R. Spencer;M. Laudenslager;L. Watkins;S. Maier
中科院分区：
文献类型：
--
作者：
M. Fleshner;T. Deak;R. Spencer;M. Laudenslager;L. Watkins;S. Maier
肾上腺糖皮质激素在介导应激源暴露的许多行为和生理效应中起重要作用。焦点主要集中在急性应激诱导的糖皮质激素[大鼠皮质酮（CORT）]升高上。然而，有报道称，暴露于慢性应激源可导致基础CORT升高和促肾上腺皮质激素结合球蛋白（CBG）降低。这些变化发生在应激引起的CORT升高之后。接下来的实验检验了暴露于急性应激源（100次5秒不可避免的尾部冲击；IS）是否也会产生基础皮质酮和CBG的长期变化。我们报道，单次IS治疗导致基础总血清CORT升高，并在IS终止后持续48-96小时。增加只出现在日波谷（早晨）。CBG水平也在24-48小时内下降。这种下降既出现在日高峰（傍晚），也出现在波谷（早晨）。这些变化导致生物活性CORT（未结合或游离）的百分比和数量增加。因此，糖皮质激素敏感的目标暴露于高水平的游离CORT数天后IS终止。这里报道的游离CORT的长期增加可能在介导IS和其他急性应激源产生的一些影响中起重要作用。
Adrenal glucocorticoids play an important role in mediating many of the behavioral and physiological effects of exposure to stressors. Focus has been primarily on the acute stress-induced rise in glucocorticoids [corticosterone (CORT) in the rat]. There are reports, however, that exposure to chronic stressors can produce an increase in basal CORT and a decrease in corticotropin-binding globulin (CBG). These changes occur subsequent to the stress-induced rise in CORT. The following experiments examined whether exposure to an acute stressor (100 5-sec inescapable tail shocks; IS) could also produce long term changes in basal CORT and CBG. We report that a single session of IS results in an increase in basal total serum CORT that persists 48-96 h after IS termination. The increase is present only at the diurnal trough (morning). CBG levels ae also decreased for 24-48 h. The decrease is present at both the diurnal peak (evening) as well as the trough (morning). These changes result in an increase in the percent and amount of biologically active CORT (unbound or free). Thus, glucocorticoid-sensitive targets are exposed to high levels of free CORT for several days after IS termination. The long term increase in free CORT reported here may play an important role in mediating some of the effects produced by IS as well as those produced by other acute stressors.