Abstract:Objective To observe the changes of KYNA, QUIN, KMO, 3-HAO, KAT in hippocampus of rats with depression, and to reveal the biological mechanisms of electro-acupuncture treating depression.Method Totally 24 SD rats were randomly divided into 4 groups (blank group, model group, fluoxetine group, and electroacupuncture group). The blank group did not receive any intervention, and the other three groups replicated the model of chronic stress depression by chronic mild unpredictable stress stimulation combined with orphanage. The locomotor activity of rats in every group by open-field experiment was observed. Hippocampus were collected, and the level of KYNA, QUIN was detected with Elisa. The KMO mRNA, 3-HAO mRNA, and KAT mRNA were detected with real-time PCR.Result In the open field test of rats, there was significant difference in the number of horizontal and vertical movements of rats in the model group before and after stress (P < 0.05). After 21 days of stress, the number of horizontal and vertical movements of rats in the model group decreased compared with that before stress, while this change was reversible in fluoxetine group and electroacupuncture group. The content of KYNA in hippocampus of model group was lower than that of blank group (P < 0.05), and the content of KYNA in hippocampus of electroacupuncture group was higher than that of model group (P < 0.05); The content of QUIN in hippocampus of model group was higher than that of blank group (P < 0.05), and the content of QUIN in hippocampus of fluoxetine group and electroacupuncture group was lower than that of model group (P < 0.05). The relative expressions of kmo mRNA, 3-hao mRNA and Kat Ⅱ mRNA in hippocampus of model group were higher than those in blank group (P < 0.05), while those in fluoxetine group and electroacupuncture group were lower than those in model group (P < 0.05).Conclusion Electroacupuncture may relieve depression through adjusting the abnormal of kynurenine pathway.