慢性应激抑郁模型大鼠下丘脑单胺类神经递质变化及相互关系

目的研究慢性应激抑郁模型大鼠下丘脑内单胺类神经递质变化及其相互关系。方法首先采用Open-Field法对大鼠进行行为学评分,将得分相近的16只大鼠随机分为对照组和模型组,每组8只。慢性应激造模后.用高效液相色谱-电化学法测定大鼠下丘脑单胺类神经递质5-羟色胺(5-HT)及其代谢产物5-羟吲哚乙酸(5-HIAA)、去甲肾上腺素(NE)及其代谢产物3-甲氧基-4-羟苯乙二醇(MHPG)、多巴胺(DA)及其代谢产物高香草酸(HVA)的含量。结果与对照组比较,模型组大鼠5-HT、5-HIAA、NE、MHPG、DA和HVA含量明显下降(P<0.01);对照组大鼠MHPG与5-HIAA呈正相关(r=0.9576,P<0.05)。模型组大鼠MHPG/5-HIAA比值(2.50±0.69)低于对照组(2.63±0.43),但差异无统计学意义。结论在抑郁大鼠下丘脑内3种神经递质及其代谢产物的浓度明显下降,支持抑郁症5-HT能、NE能和DA能低下假说,同时发现在对照组大鼠下丘脑内5-HT能与NE能系统之间存在着相互关系,而在抑郁症时这种关系发生紊乱。

Changes of monoamine neurotransmitters and their metabolites levels in hypothalamus and correlation between them in depressed rats

Objective To explore the changes of levels of monoamine neurotransmitters and their metabolites and the correlation between them in hypothalamus of depressed rats. Methods The depression model of rats was established by chronic unpredictable mild stress. The changes of the monoamine neurotransmitters and their metabolites levels in hypothalamus were determined by HPLC-ECD. Results Compared with control group,the monoamine neurotransmitters and their metabolites levels decreased remarkably in hypothalamus of depressed rats (P<0.01). A positive correlation was observed between concentrations of 5-HT metabolite 5-HIAA and norepinephrine metaholite MHPG in the hypothalamus of control group (r=0.9576,P<0.05),while depressed rats did not show such correlation. The 5-HIAA/MHPG ratio of depressed rats was lower than that of control group,but the difference was not significant. Conclusions Monoamine neurotransmillers and their metabolites were significantly decreased in depressed rats. Furthermore, a positive correlation was observed between mean concentrations of 5-HIAA and MHPG in the hypothalamus of control group while, in contrast, depressed rats showed no such correlation. These data support the hypothesis that a disturbance in the interaction between the serotoninergic and noradrenergic systems exists in depression.