雌二醇对强迫游泳实验中大鼠行为及海马和杏仁核5-羟色胺转运体表达的影响

摘要

Objective To investigate the effects of estradiol on behavior and expression of serotonin transporter (SERT) protein in hippocampus and amygdala in bilaterally ovariectomized rats in forced swimming test. Methods Twenty-eight adult female SD rats were randomly divided into control group, stress group, estradiol group and fluoxetine group (n =7). Three weeks after bilateral ovariectomy, drugs were administered to rats for 14 d. On the fourteenth day of administration, rats in stress group, estradiol group and fluoxetine group were subjected to 15 min forced swimming test, and the behavior of rats was evaluated. The expression of SERT in hippocampus and amygdala of rats in each group was determined by immunofluorescence histochemical method. Results In forced swimming test, the counts of swimming behavior in estradiol group and fluoxetine group were significantly more than that in stress group, while the counts of immobility behavior in estradiol group and fluoxeitne group were significantly less than that in stress group ( P < 0. 001 for all). Immunofluorescence histochemistry indicated that the integral absorbance of SERT in hippocampus and amygdala in stress group was significantly higher than that in control group ( P < 0. 001), while the integral absorbance of SERT in hippocampus and amygdala in estradiol group and fluoxeitne group was significantly lower than that in stress group (P < 0.05, P< 0.001). Conclusion Estradiol may increase the counts of swimming behavior and decrease the counts of immobility behavior of bilaterally ovariectomized rats in forced swimming test. Pretreatment with estradiol may inhibit stress-induced content increase of SERT protein in hippocampus and amygdala, which resembles the effects of antidepressant fluoxetine.%目的 观察雌二醇对强迫游泳实验中双侧卵巢切除大鼠行为及海马和杏仁核中5 -羟色胺转运体(SERT)蛋白表达的影响.方法 将28只成年雌性SD大鼠随机分为对照组、应激组、雌二醇组和氟西汀组(n=7).手术切除大鼠双侧卵巢后饲养3周,第4周开始慢性给药14 d.第14天时应激组、雌二醇组和氟西汀组大鼠进行15 min强迫游泳实验,评定大鼠行为.免疫荧光组织化学法检测各组大鼠海马和杏仁核中SERT表达.结果 雌二醇组和氟西汀组大鼠游泳行为计数分别显著多于应激组,而不动行为计数显著少于应激组,差异均有统计学意义(均P ＜0.001)；免疫荧光组织化学法检测结果 显示:应激组大鼠海马和杏仁核中SERT积分吸光度显著高于对照组(均P＜0.001),而雌二醇组和氟西汀组海马和杏仁核中SERT积分吸光度均显著低于应激组(P＜0.05,P＜0.001).结论 雌二醇可使双侧卵巢切除大鼠在强迫游泳实验中的游泳行为增加,不动行为减少；预先给予雌二醇可阻止应激引起海马和杏仁核SERT蛋白含量增加,作用与抗抑郁药物氟西汀相似.