Objective: To investigate the effects of Kaixin Jieyu decoction(KJD) on changes of 5-HT contents and the gene-expression of 5-HT receptor subtypes in the brain of rats with depression. Method: SD rats were randomly divided into 4 groups:control

depression model (CUMS)

CUMS+KJD

CUMS+fluoxetine. The depression model of rat was established by chronic unpredictable mild stress (CUMS). The treatments were given contemporarily

KJD group was given crud drug 22 g · kg-1

as fluoxetine was given 2.4 mg · kg-1

and the other groups were given same volume normal saline for once a day for 22 days. Regularly changes on body weight were evaluated and the behaviors changes were recorded after 1

8

15

22 days;22 d later

the cerebral cortex and hippocampus were acquired respectively

the content of monoamines neurotransmitter 5-HT in cerebral cortex was determined by HPLC-ECD and the 5-HT1A/ 2A receptor mRNA were determined by real-time PCR. Result: Compared with control group

the growth of body weight was significantly decreased in those CUMS-induced groups

the consumption of hedonia and number of the horizontal and vertical activity were decreased also (P<0.01

P<0.05)

while increased gradually (P<0.05) in the KLD group. The total 5-HT levels in cerebral cortex were declined in CUMS-induced groups

while those in KJD and fluoxetine groups were increased remarkable (P<0.05). In cerebral cortex of the control group

5-HT1A mRNA level declined while 5-HT2A mRNA level increased

both KJD and fluoxetine showed different decreasing effects. As those in hippocampus

changes were reversed. Conclusion: The depression model of rat can be established by CUMS. These CUMS-induced depression state can be ameliorated by KJD

and possible mechanism consists of improving the level of 5-HT in cerebral cortex and increasing 5-HT1Areceptor mRNA in hippocampus and 5-HT2A receptor mRNA in cerebral cortex

meanwhile reducing 5-HT2A receptor mRNA in hippocampus and 5-HT1A receptor mRNA in cerebral cortex.