目的探讨外源性糖皮质激素对大鼠下丘脑亨廷顿蛋白相关蛋白1(HAP1)表达的影响。方法成年雄性Wistar大鼠80只,随机分为实验对照组(注射生理盐水)、皮质酮注射组、皮质酮+皮质酮受体拮抗剂(RU38486)注射组、饮用氢化可的松组。皮质酮注射[(5mg/(kg.12h)]组又分为注射持续1d、3d、5d、7d组;皮质酮+皮质酮受体拮抗剂(RU38486)注射[(10mg/(kg.12h)]组注射持续3d;饮用氢化可的松组大鼠饮用水中加氢化可的松(0.01g/L),连续1个月。应用RT-PCR、免疫印迹法观察大鼠下丘脑HAP1表达的变化。结果注射皮质酮1d和3d后,下丘脑HAP1表达明显减少,其mRNA的表达明显下调,5d后HAP1开始回升,7d后恢复到正常水平,HAP1mRNA表达5d后明显增加,并高于正常水平;长期(一个月)饮用氢化可的松的大鼠,其下丘脑中HAP1的表达明显减少;在皮质酮注射的同时注射RU38486,可以对抗由皮质酮注射所引起的下丘脑HAP1的变化。结论外源性过量糖皮质激素能影响下丘脑HAP1的表达,下丘脑中的HAP1可能参与下丘脑神经元或神经内分泌细胞的功能活动。
Objective To investigate the effect of glucocortieoid on the expression of Huntingtin-associated protein 1 (HAP1) in rat hypothalamus. Methods Eighty male Wistar rats were divided into 4 groups : control group ( injection of 0.9 % saline, n = 24), corticosterone group[ ( injection of corticosterone, 5mg/( kg. 12h), n = 40 ], cortieosterone + RU38486 group [ con-injection of corticosterone with its receptor antagonist RU38486, 10mg/( kg. 12h), n = 8 ] and Hydrocortisone group[ orally given hydroeortisone (O.Olg/L)in drink water, n = 81. Corticosterone group was further divided into cortieosterone lday, corticosterone 3days, corticosterone 5days and eorticosterone 7days group according to the difference in time after corticosterone - injection. The expression of HAP1 was studied 3days after co-injection of cortieosterone and RU38486 in eorticosterone + RU38486 group. Hydrocortisone was consecutively applied in the drink water for 1 month in hydrocortisone group. RT-PCR and Western blotting were used to explore the expression of HAP1 in rat hypothalamus, Results The expression of HAP1 and the level of its mRNA were decreased significantly in hypothalarous lday and 3days after injection of eorticosterone. The expression of HAP1 began to increase 5days after injection of cortieosterone and recovered to the control level 7days after injection. The mRNA of HAP1 increased markedly 5days after injection and the level was higher than that of control group. The expression of HAP1 in hypothalamus significantly decreased in hydrocortisone group. Co-injection of eortieosterone with RU38486 blocked corticosterone - induced action on HAP1 expression in hypothalamus. Conclusion Extrinsic over-dose of glucocorticoid -injection affects the expression of HAP1 in hypothalamus and hypothalaroic HAP1 may be related with the functional activity of hypothalamns neurons or neuroendocrine cells.