Campmany L, Pol O, Armario A
Departamento de Biología Celular y Fisiología, Universidad Autónoma de Barcelona, Spain.
Pharmacol Biochem Behav. 1996 Mar;53(3):517-23. doi: 10.1016/0091-3057(95)02044-6.
The effects of chronic exposure (27 days) to two different stressors on brain monoaminergic activity was studied in adult male rats. The stressors used were restraint in tubes (RES) and immobilization in wooden boards (IMO). Both chronically stressed and stress naive (control) rats were subjected to 0, 15, and 60 min of the same stressor to which they were chronically exposed. Previous chronic exposure to either RES or IMO significantly reduced ACTH response to the same stressor. Monoaminergic response to these stressors was studied by measuring the levels of noradrenaline (NA), serotonin (5-HT) and their metabolites: 3-methoxy,4-hydroxyphenyletileneglycol sulfate (MHPG-SO4) and 5-hydroxyindoleacetic acid (5-HIAA), respectively. The regions studied were: pons plus medulla, midbrain, hypothalamus, hippocampus, and frontal cortex. Previous chronic exposure to the stressors induced only few changes in the resting levels of the monoamines and their metabolites. In addition, monoaminergic response to the same stressor to which they were chronically exposed was always similar in control and chronically stressed rats. These data indicate that brain NA and 5-HT metabolism is less sensitive than ACTH to the process of habituation to a repeated stressor, at least in the gross areas of the brain analyzed in the present study.
研究了成年雄性大鼠长期暴露（27天）于两种不同应激源对脑单胺能活性的影响。所用的应激源为管内束缚（RES）和木板固定（IMO）。长期应激的大鼠和未经历过应激的（对照）大鼠都接受了0、15和60分钟与它们长期暴露相同的应激源刺激。先前长期暴露于RES或IMO均显著降低了对相同应激源的促肾上腺皮质激素反应。通过分别测量去甲肾上腺素（NA）、血清素（5-HT）及其代谢产物：3-甲氧基-4-羟基苯乙二醇硫酸盐（MHPG-SO4）和5-羟吲哚乙酸（5-HIAA）的水平来研究对这些应激源的单胺能反应。所研究的脑区包括：脑桥加延髓、中脑、下丘脑、海马和额叶皮质。先前长期暴露于应激源仅引起单胺及其代谢产物静息水平的少量变化。此外，对照大鼠和长期应激大鼠对它们长期暴露相同应激源的单胺能反应总是相似的。这些数据表明，至少在本研究分析的脑大体区域中，脑NA和5-HT代谢对比促肾上腺皮质激素对重复应激源的习惯化过程不太敏感。
