强迫游泳和糖皮质激素促进小鼠对吗啡的条件性位置偏爱

Forced swimming and glucocorticoids facilitate the conditioned place preference induced by morphine in mice

目的 探讨应激和糖皮质激素在发生药物依赖行为中的作用机制。方法 (1)将 30只雄性昆明品系小鼠随机分为盐水组、糖皮质激素组 (2 0mg- 1 ·kg- 1 ,皮下注射 )、强迫游泳组 (2 5℃强迫游泳 10min) ,每组 10只 ,观察 3种措施对小鼠条件性位置偏爱形成的影响 ;将 30只雄性昆明品系小鼠先进行吗啡条件性位置偏爱实验 ,再随机分为盐水组、糖皮质激组和强迫游泳组 ,每组 10只 ,处理条件同前 ,持续 6天 ,观察 3种措施对小鼠条件性位置偏爱消退的影响。结果 (1)强迫游泳组和糖皮质激素组在吗啡搭配箱体中停留时间 [分别为 (9 6± 1 0 )min ,(9 4± 1 3)min]均分别高于盐水组[(7 3± 0 8)min];t1 =4 5 6 ,P1 <0 0 1;t2 =4 5 8,P2 <0 0 1,而强迫游泳组和糖皮质激素组之间差异无显著性 (t=0 41,P >0 0 5 ) ;(2 )经过 6天消退期后 ,强迫游泳组和糖皮质激素组在吗啡搭配箱体中停留时间 [分别为 (7 6± 1 1)min ,(7 4± 0 8)min]亦均分别高于盐水组 [(7 3± 1 0 )min];t1 =4 15 ,P1 <0 0 1;t2 =3 38,P2 <0 0 1。结论 强迫游泳和注射糖皮质激素均能促进小鼠对吗啡的条件性位置偏爱 ,并能延缓条件性位置偏爱的消退。

Objective This study was to explore the possible effect of stress and glucocorticoids on the drug seeking behavior in mice with morphine dependence Methods (1) Thirty mice were assigned into three group randomly and received different treatments as following: saline SC; hydrocortisone 10 mg SC; forced swimming for 10 min+saline SC; The effect of forced swimming and hydrocortisone on morphine conditioned place preference(CPP) in mice was observed (2) Thirty mice with morphine CPP were assigned into three group randomly and given the three treatments for six days as above respectively; The effect of forced swimming and hydrocortisone on extinction of morphine CCP in mice was assessed Results (1) Both of forced swimming and glucocorticoids group showed significantly increase the time spent in the morphine paired side during the test session than that of saline group( P <0 01), and there was no different in the time spent in the morphine paired side between the group of forced swimming and glucocorticoids( P >0 05) (2) After extinction for six days, both of forced swimming and glucocorticoids group also showed significantly increase the time spent in the morphine paired side than that of saline group( P <0 05) Conclusion These results suggest that forced swimming and glucocorticoids facilitate the morphine CPP and delay the extinction of morphine CCP in mice