心理应激和体力运动对大鼠海马NE及其合成酶TH、代谢酶MAOA的影响

目的： 本研究通过比较慢性心理应激（以下简称应激）和长期体力运动（以下简称运动）2种过程对大鼠海马去甲肾上腺素（NE)水平及其合成酶酪氨酸羟化酶（TH）和代谢酶单氨氧化酶A（MAOA）的影响，探讨体力运动减缓海马应激损伤的相关机制。方法：动物分别施予自愿跑轮动物模型4周和慢性束缚应激模型3周后，高效液相色谱法比较海马NE变化；蛋白免疫印迹法检测NE合成酶TH、代谢酶MAOA蛋白表达变化。结果：与对照组相比，应激大鼠体重增长缓慢，糖水偏嗜量明显降低，NE水平明显降低［（303.46±24.36) ng/g，P<0.05］，TH、MAOA蛋白表达升高，分别为(1.35±0.94）倍和（2.22±0.62)倍（P<0.05）；运动组大鼠NE水平明显升高｛（418.53±70.64) ng/g，P<0.05］，TH、MAOA蛋白表达亦升高，分别为(1.22±0.59)倍和(1.85±0.36)倍（P<0.05）。结论：结果提示NE水平变化可能与运动减缓应激性海马损伤的关系密切，NE水平的改变与NE的合成与代谢关系不密切，可能存在其它机制。

Comparison of central noradrenaline levels and its TH, MAOA between chronic psycological stress and physical exercise in rats

AIM: To investigated the changes of hippocampus noradrenaline levels and its tyrosine hydroxyase (TH), monoamine oxidase A (MAOA) expressions during chronic psycological stress procedure and physical exercise in rats. METHODS: Male Wistar rats (n=24) were randomly assigned to three conditions: (1) restraint stress (S) at 6 h/d for 3 weeks; (2) 24 h access to activity wheel running (E) for 4 weeks; (3) a sedentary control group (C). Levels of NE were assayed by high performance liquid chromatography with electrochemical detection. Protein expression of TH and MAOA were detected by Western blotting. RESULTS: Compared to C, weight loss and sucrose consumption rate decrease were induced in S, and NE was lower while TH and MAOA expressions increased significantly. In E group, NE was higher and TH, MAOA increased distinctly. CONCLUSION: It is suggested that hippocampus NE level may play an important role in the mechanism on the protection of physical exercise to chronic psycological stress, there is no close connection between NE change and TH, MAOA. Other mechanisms may exist.