雌二醇对经历强迫游泳应激大鼠中缝核色氨酸羟化酶与5-羟色胺含量的影响

Objective To investigate the effect of estradiol (E2) on tryptophan hydroxylase (TPH) and 5-hydroxytryptamine (5-HT) content in raphe nuclei of rats subjected to forced swimming stress, explore the role of estrogen and stress in disease mechanism of depression in women. Methods Three weeks after the ovariectomy, 35 ovariectomized (OVX) female SD rats were randomly divided into 5 groups (n=7): the non-stress group, the control group, the estradiol (E2) group, the fluoxetine (FLX) group and the E2+FLX group. Animals were administered with different drugs for 2 weeks. On the fourteenth day, animals except those in the non-stress group were subjected to the 15-min forced swimming test (FST). 2 hours after the FST, all animals including those in the non-stress group were perfused with 4% paraformaldehyde and brains were removed for TPH and 5-HT immunofluorescence staining. We compared the content of TPH and 5-HT by observing and calculating the integrated optical density (IOD) of immunofluorescent-positive signals in raphe nuclei. Results (1) The IOD value of TPH- and 5-HT-positive region in raphe nuclei of rats in the control group was significantly lower than that of non-stress group (P<0.01). (2) It has been shown that the IOD value of TPH- and 5-HT-positive region in raphe nuclei of rats in the E2 group, FLX group and E2+FLX group was significantly higher than that in the control group (P<0.05). Conclusion Forced swimming stress can decrease the TPH and 5-HT content in raphe nuclei. Such changes can be prevented by giving estradiol in advance. Same results were observed with antidepressant-fluoxetine. These effects may underlie the role of estradiol and stress in the disease mechanism of depression in women.