Involvement of neuropeptides in the hypothalamus and limbic system in the adaptation of stress response

为了阐明下丘脑-垂体-肾上腺（HPA）轴和神经内分泌-免疫系统对应激的适应过程，本研究采用Wister雄性大鼠进行了三个实验，结果如下：1. 16小时的长期束缚应激引起了适应性变化，其特征是下丘脑室旁核（PVN）中c-fos mRNA/Fos蛋白表达和血浆促肾上腺皮质激素（ACTH）水平短暂增加并逐渐恢复至基础水平，并且在缓慢恢复后短暂下降。一些总的白色血细胞和一些淋巴细胞亚群，尽管循环皮质酮（CORT）仍处于较高水平.在束缚16小时的大鼠中观察到叠加冷应激诱导的室旁核小细胞区c-fos mRNA/Fos的再表达。c-fos基因在复合冷应激大鼠中的表达程度与单纯冷应激大鼠（正常反应）相同。等离子AC 关于我们 复合冷应激组TH水平显著高于单纯冷应激组（高反应性、易化性）。复合冷应激大鼠血浆CORT水平与单纯冷应激大鼠（无高反应性）无显著性差异.重复束缚应激（1h/d）大鼠血浆ACTH、CORT水平、室旁核c-fos mRNA和AVP mRNA表达在7 d和14 d时均呈下降趋势（习惯化）。而在反复冷（4℃）+束缚应激大鼠中则未观察到这些反应的习惯化，提示应激反应的适应性可能发生在不同的应激情境中，且对叠加应激的应激反应在HPA轴的各个水平上可能以不同的方式发生，应激反应的适应化或易化可能与应激源的种类有关。少

In order to clarify the processes of adaptation to stress in hypothalamic pituitary adrenal (HPA) axis and neuroendocrinoimmune system, three experiments were performed using Wister male rats.The results were following.1. A long-duration restraint stress for 16 hours evoked adaptive change, characterized by transient increase and gradual recovery to basal level in c-fos mRNA/Fos protein expression in the hypothalamic paraventricular nucleus (PVN) and in plasma adrenocorticotropin (ACTH) levels, and transient decrease following slow recovery in a number of total white blood cells and some lymphocytes subpopulations, although circulating corticosterone (CORT) remained at high level.2. Superimposed cold stress-induced re-expression of c-fos mRNA/Fos in the parvocellular region of the PVN was observed in 16 hours restraint rats. The degree of expression of c-fos gene in superimposed cold stress rats was the same as those observed in single cold stress rats (normo-responsive). The plasma AC … More TH levels in superimposed cold stress rats were significantly higher compared with those in single cold stress rats (hyper-responsive, facilitation). There was no significant differences between plasma CORT level s superimposed cold stress rats and those in single cold stress rats (not hyper-responsive).3. The plasma ACTH and CORT levels, c-fos mRNA and AVP heteronuclear RNA expression in the PVN in the repeated restraint stress (1 hour/day) rats showed the decreasing tendency (habituation) at 7 days and 14 days later comparing with those at the first experiment day. On the other hand, the habituation of these responses was not observed in repeated cold (4℃)+restraint stress rats.These results suggest that adaptation of stress response may occur in various stressful situation and the stress response to a superimposed stressor may occur in a different way at each level of the HPA axis, and that occurrence of habituation or facilitation of stress response to repeated stressors may related the sort of stressors. Less