长期应激对大鼠行为和部分内分泌免疫指标的影响

The effects of chronic stress on behavior and serum ACTH, CORT, TNF, IL-1β, IL-2 in rats

目的研究长期温和不可预知的应激对大鼠行为和血浆促肾上腺皮质激素（ACTH）、皮质醇（CORT）、肿瘤坏死因子（TNF）、白介素-1β（IL-1β）和白介素-2（IL-2）的影响。方法用敞箱实验、糖水消耗实验和Morris水迷宫实验观察行为学变化,用放射免疫法观察血浆ACTH、CORT、TNF、IL-1β和IL-2的变化。结果在敞箱实验中,应激组水平得分在第4,5,6,7周[分别为（23.5±29.0）分,（16.7±17.4）分,（11.7±12.7）分,（20.8±17.1）分]低于对照组[分别为（51.2±32.1）分,（57.4±51.4）分,（65.7±46.3）分,（60.4±40.9）分],差异具有显著性（P〈0.05）,垂直得分在第6、7周[分别为（3.7±4.6）分,（5.3±4.8）分]低于对照组[分别为（18.8±17.9）分,（16.5±13.4）分],差异具有显著性（P〈0.05）,清洁时间在第7周[（55.2±45.6）s]高于对照组[（18.3±22.4）s],差异具有显著性（P〈0.05）,应激组的中央格停留时间和粪便颗数与对照组差异无显著性;糖水消耗实验中,2组间差异无显著性;在Morris水迷宫实验中,2组间差异无显著性;应激组血清ACTH、TNF、IL-1β、IL-2与对照组差异无显著性,应激组血清CORT[（1.92±1.07）ng.ml-1]比对照组[（3.73±2.21）ng.ml-1]低,差异具有显著性（P〈0.05）。结论经过长期温和不可预知的应激后,大鼠在敞箱中的行为表现会降低,但随着时间的推移,行为能力增强;大鼠在糖水消耗和Morris水迷宫实验中,均没有改变;大鼠的血清CORT出现了降低,血清ACTH、TNF、IL-1β和IL-2均没有变化。

Objective To investigate the effect of chronic mild unpredictable stress on behavior and serum ACTH, CORT,TNF, IL-1 β, IL-2 in rats. Methods During the whole procedure, stressed and non-stressed rats were tested in open field box, in Morris water maze （MWM）, and were tested for sucrose preference. Serum ACTH,CORT,TNF, IL-1 β,IL-2 were determined using a radioimmunoassay. Results In open-field test, squares crossed of stressed were reduced significantly from 4th to 7th week （ P 〈 0.05 ） , and rears were reduced significantly from 6th to 7th week（ P 〈 0.05 ）, and grooming time were increased significantly in the 7th week（ P 〈 0.05 ）, and there was no difference between two groups on central time and defecation. In sucrose consumption test, there was no significant difference between two groups. In MWM latency test, there was no difference between two groups on the time to reach the hidden or visible platform. In probe test, the duration of the time spent in the correct quadrant did not differ. Serum CORT of rats exposed to stress was reduced significantly（ P 〈 0.05 ）. Conclusion After being exposed to chronic mild unpredictable stress, rats displayed poorly in open-field test, but the score increased with the lapse of time. rats didn＇ t displayed anhedonia and had the same reward responsiveness with control group. The spatial memory of stressed rats were not changed. Serum CORT of stressed rats was reduced, meanwhile serum ACTH,TNF, IL-1 β,IL-2 were not changed.