海马Glu与抑郁症的关系及其对胃运动的影响

THE ASSOCIATION OF HIPPOCAMPAL GLUTAMATE WITH DEPRESSION AND THE EFFECTS ON GASTRIC MOBILITY

目的:探讨抑郁症的发生与海马谷氨酸(Glu)的关系及其对胃运动的影响。方法:运用慢性不可预见性温和应激(CUMS)建立抑郁动物模型,采用海马定位微量注射,通过体重变化率、糖水偏爱、敞箱、强迫游泳实验观察大鼠行为表现,用PowerLab/8sp生理信号采集分析系统记录胃内压,观察胃运动的变化。结果:慢性不可预见性温和应激21 d,可显著降低大鼠的体重增长率,糖水偏爱率和敞箱实验的水平运动和垂直运动得分,增加了大鼠的游泳不动时间,与正常对照组相比,差异显著。同时大鼠平均胃内压和胃的收缩幅值也显著降低。海马微量注射Glu与慢性不可预见性温和应激引起的动物行为表现一致,而胃运动减弱的程度小于应激组,但与正常对照组比较,差异明显。海马微量注射NMDA受体阻断剂MK-801,可消除应激所引起的抑郁样行为,减弱应激对胃内压的抑制作用,并明显增大胃的收缩幅值。结论:海马Glu和NMDA受体与应激性抑郁发生密切相关,既参与了应激引起的行为变化,又参与了应激引起的胃活动变化,只是对行为影响和胃活动影响有所不同。

Aim： To explore the relationship between the pathology of depression and glutamate（Glu） in hippocampus, and the effect on gastric mobility. Methods： Depression model was established by using the chronic unpredicted mild stress（ CUMS）. And stereotaxie and intra-hippocampal micminjection were also used in this experiment. Rat emotion and behaviors were observed by the change in body weight, sucrose prefe rence-test, open field-test and forced swimming-test. Intragastric pressure and mobility were recorded with the instrument of Powerlab/8sp. Results： Compared with the control, 21-day CUMS significantly reduced the increase in body weight, rat sucrose preference, locomotor activity and rearing in open field test, while it significantly increased duration of immobility time in forced swimming test. Meanwhile, magnitudes of intragastric pressure and mobility were significantly declined after 21 days CUMS. Microinjection of Glu into hippocampus mimics the behaviors which were produced in CUMS. The down-rang of gastric mobility in the group of Glu injection was smaller than CUMS, but was much larger than the control. Intrahippocampal microinjection of MK-801 attenuated depression-hke behaviors induced by stress, weakened stress-induced inhibition of intragastric pressure, and augmented the magnitudes of gastric contraction. Conclusion： Glu and NMDA receptor in hippocampas are to do much with the etiology of stressinduced depression. They are not only concerned with behavioral changes induced by stress, but also with the variation of gastric activities, nevertheless, differences exist between the effects of behaviors and gastric activities.