RESUMO
Objective: To investigate the antidepressant roles of estrogen in the perimenopausal depression rat model and po- tential mechnisms. Methods: The perimenopausal depression rat model was performed by ovariectomized(OVX)rat following unpre- dictable chronic mild stress(UCMS). The rats were divided into 6 groups:the control group(CON),OVX group,model (OVX+UC- MS)group,estrogen(estradiol,E2)treatment group,escitalopram group(ESC),and OVX+E2 group. Open filed and sucrose prefer- ence tests were used to investigate depression-like behavior. Nissl staining was used to analyze neuron numbers in the dentate gyrus (DG)region of rat hippocampus,Levels of 5-HT,5-H1AA, norepinephrine(NE)and dopamine(DA)in the hippocampus were deter- mined by the HPLC method,while the levels of several markers associated with HPA axis were determined by ELISA. Results: OVX+ UCMS decreased the number of crosses and rearings in open field test and decreased sucrose preference in sucrose preference test in the perimenopausal depression rat model. E2 treatment could reverse the depression behavior. E2 treatment also reversed the de- creased neuron numbers of DG region in the rat hippocampus and decreased monamine transmitter and high hypothalamic-pituitary-ad- renal axis(HPA)activation. Conclusion: E2 plays antidepressant roles in perimenopausal depression rat model through protecting neuron,increasing monamine transmitter level and decreasing HPA axis activation.