5-羟色胺转运体敲除小鼠在应激下焦虑行为和HPA轴的改变

目的研究5-羟色胺转运体(serotonin transporter,SERT)敲除小鼠焦虑行为及ACTH和皮质酮分泌变化。方法将基因型为SERT+/-的雌雄小鼠交配产子,并把鉴定后子代小鼠按基因型(SERT+/+、SERT+/-、SERT-/-)分为对照组和EPM组,每组15只。利用高架十字迷宫作为应激原刺激小鼠,观察各组小鼠的焦虑行为,并测定各组小鼠的ACTH和皮质酮分泌。结果①基因型PCR成功鉴定SERT+/+、SERT+/-和SERT-/-的小鼠。②SERT+/-和SERT-/-小鼠的开臂停留时间、开臂停留时间百分比、进入开臂的次数和进入开臂的次数百分比较SERT+/+均显著降低(P<0.05,P<0.01)。③EPM刺激下,SERT+/-和SERT-/-小鼠ACTH分泌的增加显著高于SERT+/+(P<0.05),SERT-/-小鼠皮质酮分泌的增加显著高于SERT+/+(P<0.05)。结论 SERT敲除小鼠在应激条件下易产生焦虑,并且ACTH和皮质酮分泌显著升高。

Change of anxious behavior and hypothalamic-pituitary-adrenal axis in serotonin transporter knockout mice under stress

Objective To study the change of anxious behavior and secretion of adrenocorticotropic hormore(ACTH) and corticosteron in serotonin transporter(SERT) knockout mice.Methods Heterozygous SERT mutant mice(SERT+/-) were mated to produce offspring.Thirty offspring mice were divided into control group(n=15) and elevated plus maze(EPM) group(n=15) according their genotype(SERT+/+,SERT+/-,SERT-/-).The mice were stimulated with EPM as a stressor and their anxious behaviors were observed.ACTH and corticosteron levels in the mice were measured.Results(1) The genotypes were identified in SERT+/+,SERT+/-,and SERT-/-mice respectively by PCR.(2) The open arm time(OT),the OT %,the open arm entry(OE) and OE% were significantly lower(P<0.05,P<0.01).(3) The ACTH level was significantly higher in SERT+/-and SERT-/-mice than in SERT+/+ mice after EPM stimulation(P<0.05) while the corticosteron level was significantly higher in SERT-/-mice than in SERT+/+ mice(P<0.05).Conclusion SERT knockout mice are easy to have anxiety with their ACTH and corticosteron level significantly increased under stress.