目的:观察注意缺陷多动障碍(ADHD)模型动物自发性高血压大鼠(SHR)血清皮质酮(CORT)、促肾上腺皮质激素(ACTH)、促肾上腺皮质激素释放激素(CRH)水平及下丘脑糖皮质激素受体(GR)、糖皮质激素受体(MR)、CRH及海马GR、MR mRNA的表达情况,探讨SHR大鼠下丘脑-垂体-肾上腺轴(HPA)功能及相关影响因素。方法:以幼年SHR大鼠为ADHD模型组、Wistar京都大鼠(WKY)为对照组,采用ELISA法检测血清CORT、ACTH、CRH水平,RT-PCR法检测大鼠下丘脑GR、MR、CRH及海马GR、MR mRNA的表达水平。结果:SHR大鼠血清CORT、ACTH水平明显低于WKY大鼠(P＜0.01),血清CRH水平明显高于WKY大鼠(P＜0.01),下丘脑及海马GR、MR mRNA的表达水平明显高于WKY大鼠(P＜0.01),而下丘脑CRH mRNA表达则低于WKY大鼠(P＜0.01)。结论:SHR大鼠HPA轴呈低反应性,可能与CRH启动障碍及下丘脑和海马GR、MR mRNA 高表达相关。
Objective: To observe the Levels of serum CORT, ACTH and CRH in SHR rats, the expression of GR, MR and CRH mRNA in hypothalamus and GR, MR mRNA in hippocampus of the ADHD model animal SHR rat, and to explore the HPA axis function and related factors in SHR rats. Methods: Junior SHR rats were used as ADHD model group and WKY rats as control group. The levels of CORT, ACTH and CRH in serum were detected by ELISA, and the mRNA expressions of GR, MR, CRH in hypothalamus and GR, MR in hippocampus were detected by RT-PCR. Results: The levels of serum CORT and ACTH in SHR rats were significantly lower than those in WKY rats (P<0.01), and the levels of serum CRH were significantly higher than those in WKY rats (P<0.01). GR and MR mRNA expression levels in hypothalamus and hippocampus were significantly higher than those in WKY rats (P<0.01), while CRH mRNA expression in hypothalamus was significantly lower than that in WKY rats (P<0.01). Conclusion: The HPA axis of SHR rats showed hyporesponsiveness, which may be related to CRH priming disorder and high expression of GR and MR mRNA in hypothalamus and hippocampus.