慢性应激对大鼠血管平滑肌细胞的效应及与焦虑行为的关系

目的探讨慢性精神应激对血管平滑肌细胞的影响及与焦虑行为的关系。方法将38只SD大鼠按照随机数字表随机分为精神应激组(30只)和对照组(8只)。对应激组采用限制应激和饮水冲突应激,持续2个月;分别于应激前、应激后1,2个月用空场实验和高架十字迷宫实验观察大鼠焦虑水平,计算出中央格爬行次数、外周格爬行次数、开放臂进入次数及停留时间、闭合臂进入次数及停留时间。以免疫组化方法测定主动脉血管局部增殖细胞核抗原(PCNA)表达,并用苏木素-伊红染色法观察主动脉结构变化。结果(1)与对照组比较,应激1个月后,应激组大鼠在开放臂的次数和时间、闭合臂的次数少(P<0·05),闭合臂的时间多(均P<0·01);应激2个月后,应激组大鼠在外周格爬行的个数和闭合臂时间多(P<0·01),开放臂时间少(P<0·01)。(2)应激组大鼠主动脉失去原有的正常结构,中层血管平滑肌细胞排列紊乱,数目增多。(3)应激组大鼠血管壁PCNA表达的阳性细胞数为(16485±10694)个/MM2,对照组大鼠为(4012±2256)个/MM2,T=4·359,P<0·01。(4)中度焦虑组大鼠PCNA表达与大鼠焦虑呈正相关(PEARSON相关系数为0·718,P=0·004)。结论大鼠中度焦虑时,其血管平滑肌细胞增殖率与焦虑情绪呈正相关。

The influence of chronic stress on rat aorta smooth cell and the relationship with anxiety

Objective To study the influence of chronic mental stress on rat aorta smooth muscle cell.Methods Thirty-eight SD rats were randomly divided into two groups, with 30 in stress group and 8 is controls. The rats in stress group were given drinking water conflict stress combined with restraint stress for two months. The rats anxiety behaviors were measured with elevated plus-maze and open-field tests. The proliferating cell nuclear antigen (PCNA) expressing in aorta was determined with immunohistochemistry, and the aorta structure observed microscopically after hematoxylin-eosine staining.Results The stressed rats showed marked anxiety behaviors after two-month stress. In the open field, the central entrances, surrounding entrances, total entrances were significantly decreased than the baseline, and so in the elevated-plus maze open-arm number and time. The aorta PCNA positive cells in stressed rats were significantly more than in controls (P<0.01). In rats with moderate anxiety, the PCNA expressing was positively correlated to the anxiety level. The aorta structure of stressed group changed much.Conclusion The rat aorta structure has significant changes including the medium thickening after chronic stress.