龙牡桂枝汤对ADHD模型大鼠左右额叶-纹状体α_(2A)-AR mRNA表达的影响

Effects of Longmu Guizhi Decoction on α_(2A)-AR mRNA Expression in Left and Right Frontal-striatum of ADHD Model Rats

目的:观察龙牡桂枝汤对注意缺陷多动障碍(ADHD)模型动物—幼年自发性高血压大鼠(SHR)左右额叶-纹状体α2A肾上腺素受体(α2A-AR)mRNA表达的影响,探讨该药治疗ADHD的作用机制。方法:采用幼年雄性SHR大鼠,随机分为龙牡桂枝汤高、低剂量(18,9 g·kg-1)组,盐酸哌甲酯组(3.75 mg·kg-1)和模型组(生理盐水,10 m L·kg-1),连续ig给药14d,采用Real-time PCR法检测各组大鼠左右脑前额叶皮质、纹状体α2A-AR mRNA表达水平。结果:在右前额叶皮质,盐酸哌甲酯组及龙牡桂枝汤组大鼠的α2A-AR mRNA表达较模型组显著减少(P<0.05),而在左前额叶皮质各组差异不明显。在右纹状体,与模型组相比,盐酸哌甲酯组α2A-AR mRNA的表达显著减少,而龙牡桂枝汤低、高剂量组α2A-AR mRNA的表达显著增加(P<0.05);在左纹状体,盐酸哌甲酯组α2A-AR mRNA的表达显著高于模型组和龙牡桂枝汤低、高剂量组(P<0.05),而龙牡桂枝汤低、高剂量组与模型组比较无显著性差异。结论:α2A-AR与ADHD的发生存在一定关联,龙牡桂枝汤治疗ADHD的作用机制可能与其下调右脑前额叶皮质α2A-AR mRNA表达,上调右脑纹状体α2A-ARmRNA表达有关。

Objective： To study the influence of Longmu Guizhi decoction（ LD） on the α2A-AR mRNA expression in the left and right brain of juvenile spontaneously hypertensive rat（ SHR）,a rat model of attention deficit hyperactivity disorder（ ADHD）, and to investigate the mechanisms of LD for ADHD. Method： Male SHRs were randomly divided into high-dose LD group（ 18 g ·kg- 1）,low-dose LD group（ 9 g ·kg- 1）,methylphenidate group（ 3. 75 mg·kg- 1） and model group（ saline,10 m L·kg- 1）. All the SHRs were lavaged for 14 days. The α2A-AR mRNA expression in the left and right prefrontal cortex,corpus striatum were detected by the method of Real-time PCR. Result： In the right prefrontal cortex,α2A-AR mRNA expression was significantly decreased in the methylphenidate group and two LD groups compared with model group（ P〈0. 05）,but there was no obvious change in the left prefrontal cortex in all the groups. In the right corpus striatum,compared with saline control group,α2A-AR mRNA expression was significantly decreased in the methylphenidate control group,but it was significantly increased in the two LD groups. In the left corpus striatum,α2A-AR mRNA expression was significantly increased in the methylphenidate control group（ P〈0. 05）,there was no obvious change in other groups. Conclusion： The produce of ADHD may have a certain correlation with α2A-AR. The potential mechanism of LD in the treatment of ADHD is related to that it can decrease α2A-AR mRNA expression in the right prefrontal cortex,and increase its expression in the rigtht corpus striatum.