心理应激时大鼠海马神经元的钙状态变化及锌的作用研究

STUDY ON THE EFFECTS OF STRESS ON THE CALCIUM STATUS OF HIPPOCAMPUS NEURON IN RATS WITH DIFFERENT ZINC STATUS AND RELEVANT MECHANISMS

目的 : 研究不同锌营养水平的大鼠在应激条件下的行为变化 ,观察海马细胞内游离钙 ([Ca2 + ]i)及活性钙调素 (Ca M)水平改变 ,以探讨其可能机制。方法 : 大鼠按体重随机分为缺锌组 (ZD)、缺锌应激组 (SZD) ,对喂组 (PF)、对喂应激组 (SPF) ,对照组 (CT)、对照应激组(SCT)。实验进行 1 w后 ,各应激组大鼠接受不规则光 -电刺激 ,2 5 min/ d连续 1 5 d后进行行为测定 ;分别用 Fura-2 / AM双波长荧光法和流式细胞术测定动物海马细胞 [Ca2 + ]i和活性 Ca M水平。结果 : 单纯缺锌大鼠在旷场中的中央格停留时间延长 ,修饰次数减少 ,海马细胞静息 [Ca2 + ]i浓度升高而 Ca M水平下降 ;与相应非应激组比较 ,各应激组大鼠在旷场中的水平和垂直运动减少 ,海马细胞 [Ca2 + ]i含量升高 ,以缺锌应激组最为明显 ;活性钙调素水平则呈相反变化。结论 : 光电应激导致实验大鼠在旷场中行为异常 ,并因机体缺锌而加重 ;推测海马细胞内 Ca2 + -Ca

Objective: To observe the behavior changes of rats in different zinc status under stress,and explore its possible mechanisms. Methods: Rats were randomly divided into 6 groups,i.e.,zinc deficiency group(ZD) and stress zinc deficiency group(SZD),pair fed group(PF) and stress pair fed group(SPF), control group(CT) and stress control group(SCT).At the end of the first week, rats of stress groups were given irregular photoelectric stimulus,25 min/d for 15 days, then their behavior was observed in open field test;[Ca 2+ ]i. Concentration and active CaM content of hippocampal cells were detected by Fura 2/AM two wave length fluorophotometry and flowcytometry respectively. Results: ZD rats had prolonged latency and decreased number of modifications in open field test;[Ca 2+ ]i content of ZD rats was significantly higher than that of CT rats;crossing ,rearing and modifying frequencies of rats in stress groups were less than those of corresponding non stress groups, especially of SZD group, so was [Ca 2+ ]i concentration of hippocampal cells; while active CaM content showed the opposite tendency. Conclusion: The results indicate that photoelectric stress can lead to abnormal behavior in rats which are worsened by zinc deficiency;the changes of [Ca 2+ ]i CaM system of hippocampal cells may be one of the relevant mechanisms underlying stress induced abnormal performance.