电针对慢性应激抑郁模型大鼠额叶皮层及海马Caspase-3基因表达的影响

Expression of Caspase-3 mRNA in frontal cortex and hippocampus of chronic stress-induced depression rats treated by electro-acupuncture

目的观察电针对慢性应激抑郁模型大鼠额叶皮层及海马半胱氨酸蛋白酶-3（Cysteinyl aspartate specific protease-3，Caspase-3）表达的影响，探讨电针治疗抑郁症的作用机理。方法将Sprague—Dawley（SD）大鼠48只随机数字表法分为4组：空白组、模型组、模型＋电针组（电针组）、模型＋阳性药组（帕罗西汀组），12只／组；采用旷场实验进行行为学评价；采用实时荧光定量PCR（RT—PCR）方法检测大鼠额叶皮层及海马Caspase-3mRNA含量。结果①旷场实验：与空白组大鼠[分别为水平（664-13）格、竖立（10±2）次]相比，模型组大鼠水平穿越格数[（29±7）格]、竖立次数[（6±2）次]均有减少（P〈0．05、P〉0．05）。与模型组相比，电针组大鼠水平穿越格数[（614-9）格]、竖立次数[（13±1）次]均明显提高（P〈0．01）；帕罗西汀组大鼠水平穿越格数[（39±10）格]、竖立次数[（8±1）次]有所增加，但差异无统计学意义（P〉0．05）。②RT—PCR：与空白组相比，模型组大鼠额叶皮层、海马Caspase-3mRNA含量明显升高（P〈0．05）。与模型组相比，电针组与帕罗西汀组大鼠额叶皮层Caspase-3 mRNA含量明显下降，差异有统计学意义（P〈0．05）；电针组与帕罗西汀组大鼠海马Caspase-3 mRNA含量有下降趋势，但差异无统计学意义（P〉0．05）。结论慢性应激抑郁模型大鼠额叶皮层及海马Caspase-3 mRNA含量增加，电针可以从基因水平下调其表达，这可能是电针发挥抗抑郁治疗作用的途径之一。

Objective To observe the expression of Caspase-3 mRNA in prefrontal cortex and hippocampus of chronic stress-induced depression rats, and to detect the machnisms of antidepression by electro-acupuncture. Methods Sprague-Dawley rats were randomly divided into four groups：control group, model group, model ＋ electro-acupuncture group and model ＋ paroxetine group, 12 rats in each group. Open-field test was used to observe the changes of movements, and real-time fluorescence quantitative PCR （RT-PCR） method was used to detect Caspase-3 mRNA levels in prefrontal cortex and hippocampus. Results （1）Open-field test：after stress,compared with control group rats, the model group rats＇crossing numbers （29 ±7 ） , rearing times （6 ±2 ） were apparently less than those of control group（ （ 66 ± 13 ） , （ 10±2 ） ; P〈 0.05, P〉 0.05 ）. In comparison with model group, the crossing times and rearing times being increasing in degree in electro-acupuncture group（ （61 ± 9 ） , （ 13 ±1 ） ） and par- oxetine group （ （ 39± 10） , （ 8 ± 1 ） , P 〈 0.01, P 〉 0.05 ）. （2） Compared with the control group, Caspase-3 mRNA in prefrontal cortex and hippocampus significantly increased in model group（P 〈0.05 ） ;and compared with model group, Caspase-3 mRNA in prefrontal cortex in electro-acupuncture group and paroxetine group significantly decreased （P 〈 0.05 ） ,and both expression of Caspase-3 mRNA in hippocampus in electro-acupuncture group and ex- pression of Caspase-3 mRNA in hippocampus in paroxetine group decreased （P 〉 0.05 ）. Conclusion Chronic stress can increase the expression of Caspase-3 mRNA in prefrontal cortex and hippocampus of chronic stress-in- duced depression rats,while electro-acupuncture can decrease the expression of caspase-3 mRNA,which may be an important way to anti-depression by electro-acupuncture.