心理应激对大鼠旷场行为的影响及酪氨酸干预作用研究

目的：观察心理应激对大鼠自主探究行为的影响,并探讨酪氨酸干预对心理应激动物的作用。方法：将Wistar大鼠随机分为5组（n=10）：正常对照组、应激对照组和低、中、高剂量酪氨酸补充应激组。测定动物的旷场行为表现,以放免法检测血浆皮质醇水平,以化学荧光法检测血浆去甲肾上腺素和多巴胺含量。结果：束缚应激使动物的血浆皮质醇水平明显升高,并出现体重增长缓慢。与正常对照组相比,应激对照组动物在旷场中的潜伏期延长、水平运动和垂直运动次数减少,而中剂量酪氨酸补充应激组和高剂量酪氨酸补充应激组动物的旷场行为表现未见显著差异。应激对照组和低剂量酪氨酸补充应激组动物的血浆去甲肾上腺素和多巴胺水平降低,其它动物未见明显变化。结论：应激引起动物应激激素分泌增加,旷场行为表现异常,而补充酪氨酸可减轻应激造成的这种不良影响。其机制可能涉及神经递质去甲肾上腺素和多巴胺水平的变化。

Effects of psychological stress on performances in open-field test of rats and tyrosine's modulation

Aim： To explore the effects of different doses of tyrosine modulation on behavioral performances in open field test of psychological stress rats. Methods： The animal model of psychological stress was developed by restraint stress for 21 days. Wistar rats were randomly assigned to five groups（ n = 10） as follows： control group （CT）, stress control group （SCT）, low, medium and high-doses of tyrosine modulation stress groups （SLT, SMT and SHT）. The changes of behavioral performances were examined by open-field test. Serum levels of cortisol, nore- pinephrine and dopantine were also detected. Results： The levels of serum cortisol were all increased obviously in the four stress groups, and their bodyweight gainings were diminished. The behavioral performances of SCT rats in open-field test were changed significantly in contrast to that of CT rats. However, The behavioral performances of SMT and SHT rats were not different from that of CT rats. In addition, the serum levels of norepinephrine and dopamine were downregulated obviously in SCT and SLT groups, and no differences were observed in other groups. Conclusion： Psychological stress can impair body behavioral performances, and moderate tyrosine modulation may improve these abnormal changes. The related mechanisms may be involved with the changes of norepinephrine and dopamine.