抑郁大鼠海马区代谢指标的动态变化及意义

Dynamic changes and its meaning of metabolism indices about hippocampus in rat depressive model

目的探讨大鼠抑郁模型海马区各项代谢指标的变化特征及动态变化规律。方法将40只SD大鼠随机分成对照组及抑郁组各20只,抑郁组利用孤养及慢性轻度不可预见性应激(CUMS)相结合的方法建立抑郁模型,共应激8周。实验前及每周末对各组海马进行3.0T超高场MRI扫描及磁共振质子波谱检测,指标包括N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)、谷氨酰胺和谷氨酸(Glx)、肌醇(MI)。结果与对照组相比,抑郁组左侧海马Glx/Cr值第3周开始下降、第4～8周基本维持恒定,右侧海马Glx/Cr值于第4周开始下降、第4～8周基本维持恒定(P<0.05);左侧海马Cho/Cr值于第4周升高、第5～8周升高更加明显,右侧海马Cho/Cr值于第6周升高、第7～8周升高更加明显(P<0.05);左侧海马MI/Cr值于第4周升高、第5～8周升高更加明显,右侧海马MI/Cr值于第6周升高、第7～8周升高更加明显(P<0.05);双侧海马NAA/Cr值未见明显差别。结论抑郁大鼠海马的代谢指标出现异常并呈一定规律性动态变化,此可能为构成抑郁症发病机制的神经生物学基础。

Objective To investigate the dynamic change feature and regularity of various metabolism indices about hippocampus in the rat depressive model. Methods Forty SD rats were randomly devided into control group and depres-sive group with 20 in each, the depressive group was breed solitarily and exposed to chronic unpredictable mild stress in 8 weeks. Using 3.0T MRI and analyzing technology lit-MRS to scanning and detect hippocampus of each group at the begin- ning and per week, the indices including NAA, Cr, Cho, Glx and MI. Results Compared with the control group, the values of Glx/Cr of the left hippocampus in the depressive group were significantly reduced on the 3th week, and keep the same level on the 4 th-8th week（P 〈0.05） ; the values of Glx/Cr of the right hippocampus in the depressive group were significantly reduced on the 4th week, and keep the same level on the 4th-8th week（ P 〈 0.05 ） ; the values of Cho/Cr and MI/Cr of the left hippocampus in the depressive group were significantly increased on the 4th week and especially higher on the 5th-8th week（P 〈0.05） ; the values of Cho/Cr and MI/Cr of the right hippocampus in the depressive group were sig- nificantly increased on 6th week and especially higher on the 7th-Sth week（P 〈 0.05 ）. The values of NAA/Cr of the bilat-eral hippocampus in the depressive group showed no difference compared with the control group. Conclusion The meta- bolic indices about hippocampus in depressive rat become abnormal and changes dynamically, which maybe constitute the nervous biochemical basis of depression.