目的探讨妊娠期抑郁症对大鼠中缝核色氨酸羟化酶2(TPH2)表达的影响。方法选取月龄、体质量相近的Wistar大鼠,合笼受孕后将孕鼠随机分为实验组、对照组。实验组给予18 d慢性不可预见性的温和应激(CUMS)制备妊娠期抑郁症大鼠模型,对照组在正常条件下饲养。采用旷场实验和1%蔗糖水偏爱实验对大鼠进行行为学评分,采用免疫组化SP法测定大鼠中缝核TPH2的表达。结果 18 d CUMS后,实验组大鼠旷场实验评分、蔗糖水消耗实验结果及中缝核TPH2表达量低于对照组(P均<0.01)。实验组大鼠18 d CUMS前后水平运动得分差与TPH2表达量呈负相关(r=-0.71),垂直运动得分差与TPH2表达量呈负相关(r=-0.74),中央格停留时间差与TPH2表达量呈正相关(r=0.64),蔗糖水消耗量差与TPH2表达量呈负相关(r=-0.69)。结论妊娠期抑郁症模型大鼠中缝核TPH2表达量下降可能与妊娠期抑郁症的发生有关。 Objective To investigate the effect of gestational depression on the expression of nucleus tryptophan hydroxylase 2 (TPH2) in rats. Methods Wistar rats of the same age and body weight were selected and pregnant rats were randomly divided into experimental group and control group after caged pregnancy. The experimental group was given a chronic unpredictable mild stress (CUMS) for 18 days to prepare a rat model of depression during pregnancy. The control group was fed under normal conditions. Behavioral scores of rats were evaluated by open-field test and 1% sucrose water preference test, and immunohistochemical SP method was used to determine the expression of TPH2. Results After CUMS for 18 days, the open field test, sucrose water consumption and the expression of TPH2 in the nucleus raphe nucleus in experimental group were lower than those in control group (all P <0.01). There was a negative correlation between the level of TPH2 and the level of TPH2 in the experimental group (r = -0.71), the negative correlation between the level of TPH2 and the level of TPH2 in the experimental group (r = -0.74) (R = 0.64). The difference between sucrose water consumption and TPH2 expression was negatively correlated (r = -0.69). Conclusions The decreased expression of TPH2 in the nucleus raphe nucleus in the rat model of depression during pregnancy may be related to the occurrence of depression during pregnancy.