Lactuside B对缺血性脑损伤大鼠海马和纹状体NT-3 mRNA表达的影响

Effects of Lactuside B on the NT-3 mRNA in rats′ hippocampus and striatum after ischemic brain injury

目的探讨Lactuside B对缺血性脑损伤大鼠海马和纹状体NT-3 mRNA表达的影响。方法 SD雄性大鼠,体重280～320g,随机分为假手术组、模型组、阳性药物对照组、Lactuside B低剂量组、中剂量组和高剂量组,共6组,8只/组。采用大鼠大脑中动脉缺血再灌注损伤模型,各组动物均按5ml/kg的容量腹腔注射相应的实验药物,每天给药一次。动物持续脑缺血2h,在再灌注24h和72h对其神经系统体征进行客观评分后分别处死4只动物,采用RT-PCR技术检测大鼠海马和纹状体不同时间段NT-3 mRNA的表达。结果研究发现Lactuside B各剂量组均可降低神经缺损症状评分,提高海马和纹状体NT-3 mRNA的表达,且低、中剂量组作用较好,与模型组和阳性对照药比较有显著性差异(P<0.05或P<0.01),用药72h后两部位的NT-3mRNA表达更多,与24h比较有显著性差异(P<0.05或P<0.01)。结论 Lactuside B可通过上调海马和纹状体NT-3 mRNA的表达起到抗缺血性脑损伤的作用,两部位升高的NT-3 mRNA对目标蛋白的合成具有积极的导向性质。

Objective To explore the effects of Lactuside B on NT-3 mRNA expression in rats′hippocampus and striatum after ischemic brain injury.Methods SD male rats,weighted 280 320g,were randomly divided into sham operation group,model group,positive control group,Lactuside B low-dose,middle-dose group,and high-dose group,8 rats per group.The middle cerebral artery ischemia-reperfusion injury model were adopted.All animals were abdominally injected 5ml/kg corresponding experimental drugs once a day.The animals were sustained cerebral ischemia for 2h,then separately sacrificed at 24h and 72h after reperfusion.The injury of nervous system were objectively scored.RT-PCR was used to detected expression of NT-3 mRNA in the hippocampus and striatum on different time points.Results All groups of Lactuside B showed reduce in the neurological deficit scores,and improvement in NT-3 mRNA expression in the hippocampus and striatum.Generally,the effects of low and medium dose groups were better than model group and positive control medicine（P〈0.05 or P〈0.01）,and NT-3 mRNA expression of 72h ischemic brain injury was more than 24h in two parts（P〈0.05 or P〈0.01）.Conclusion The actions of Lactuside B on anti-ischemic brain injury may be a result as increase NT-3 mRNA expression the hippocampus and striatum,which has a positive-oriented nature on the synthesis of target protein.