杞菊地黄汤对视网膜变性大鼠半胱氨酸天冬氨酸蛋白酶-3表达的影响

Influence of Qiju Dihuang Decoction on Caspase-3 Expression in Retinal Degeneration Rats

目的:观察杞菊地黄汤对实验性视网膜变性大鼠的治疗机制。方法:将生后45 d的SD大鼠分为正常组、模型对照组和杞菊地黄汤组,正常组不做处理,生后47 d中药组大鼠灌服杞菊地黄汤8.3 g.kg-1(15 mL.kg-1),模型对照组同时灌服等体积生理盐水,生后50 d ip N-甲基-N-亚硝脲(N-methyl-N-nitrosourea,MNU)40 mg.kg-1造成视网膜变性模型,正常组第55天处死,后2组大鼠分别按造模后12 h,1,2,3,5 d处死,应用免疫组织化学法检测视网膜中半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)的表达,实时荧光定量RT-PCR法检测视网膜中Caspase-3的含量。结果:免疫组织化学和实时荧光定量RT-PCR法均显示模型对照组大鼠视网膜Caspase-3阳性表达在MNU处理后渐升高,第2天达顶峰,第5天有所下降;杞菊地黄汤组大鼠视网膜Caspase-3阳性表达第3天才达顶峰,且高峰值低于模型组。结论:杞菊地黄汤能延缓MNU ip所导致的大鼠视功能损害,其治疗机制与降低视网膜中Caspase-3的表达,从而抑制光感受器细胞的凋亡有关。

Objective： To explore the influence of Qiju Dihuang decoction on Caspase-3 expression in N- methyl-N-nitrosourea （MNU） -induced retinal degeneration rats. Method： Sprague Dawley rats were divided into three groups ： the control group, the model group and the Qiju Dihuang decoction group. MNU at dose 40 mg·kg-1 was ip injected at 50 d after birth to induce retinal degeneration model. All rats were sacrificed at scheduled time points. The expression of Caspase-3 on the retina was detected by immuohistochemistry and Real-Time PCR. Result： The results were demonstrated by immuohistochemistry and Real-Time PCR. Positive Caspase-3 expression in the model group was detected at 12 h after ip MNU, reached to the peak at 2 d and gradually reduced, whereas Caspase-3 expression in the Qiju Dihuang decoction group reached to the peak at 3 d and the peak value was lower than the former. Conclusion： The positive expression of Caspase-3 was raised after MNU injection. Qiju Dihuang decoction can restrain the apoptosis of photoreceptor cells by decreasing the expression of Caspase-3.