生命早期应激对成年大鼠自发活动和外周血皮质酮水平的影响

目的 观察生命早期应激对大鼠成年后自发活动和外周血皮质酮水平的影响.方法 以母子分离和孤养为早期应激手段,建立生命早期应激模型;成年后大鼠接受14天慢性应激:足底电击(电流1mA,6次/min,1s/次,10min,随机频率),用开场试验检测大鼠自发活动情况,用ELISA法测定外周血皮质酮浓度.结果 早期应激大鼠成年后自发活动总活动时间为(296.96±6.63)s],高于对照组大鼠为(291.06±8.40)s], 差异具有显著性(P＜0.01),早期应激大鼠外周血皮质酮浓度为(15.51±2.41)nmol/L],高于对照组大鼠为(11.27±2.49)nmol/L], 差异具有显著性(P＜0.05);再接受14d慢性应激后,大鼠自发活动总活动路程和总活动时间分别为(23231.29±2030.35)mm和(296.39±3.48)s],高于对照组大鼠分别为(14042.81.06±2875.34)mm和(259.18±4.71)s], 差异具有显著性(分别为P＜0.05和P＜0.01),外周血皮质酮浓度 (20.60±1.83)nmol/L],高于对照组大鼠(14.49±1.37)nmol/L], 差异具有显著性(P＜0.01).结论 早期应激可使大鼠成年后自发活动增加,外周血皮质酮浓度升高,下丘脑-垂体-促肾上腺皮质轴对应激的反应性增强.

Effect of early life stress on locomotion and corticosterone in peripheral blood in adult rats

Objective To investigate the effect of early life stress on the locomotion and concentration of corticosterone in peripheral blood in adult rats.Methods Maternal deprivation and isolation were used in the model of early life stress. Chronic stress was used in adult rats.Open field test was used for the measurement of locomotion activity. ELISA was used to measure the concentration of corticosterone in peripheral blood.Results The total activity time of locomotion(296.96±6.63)s, (291.06±8.40)s;P＜0.01] and the concentration of corticosterone (15.51±2.41)nmol/L,(11.27±2.49)nmol/L;P＜0.05]were increased in adult rats by maternal deprivation. The total activity distance (23231.29±2030.35)mm,(14042.81.06±2875.34)mm;P＜0.05] and time(296.39±3.48)s,(259.18±4.71)s;P＜0.01]were increased after chronic stress which was used in adult rats in which maternal deprivation were used before. The concentration of corticosterone(20.60±1.83)nmol/L,(14.49±1.37)nmol/L;P＜0.01]was also increased in the same condition.Conclusions The concentration of corticosterone and locomotion activity of adult rats can be increased by early life stress. The reaction of HPA axis for chronic stress was improved by early life stress.