褪黑素对马桑内酯致痫大鼠海马及皮质内TNF-α水平的影响

EFFECTS OF MELATONIN ON TNF-α LEVEL IN HIPPOCAMPUS AND CORTEX OF RATS WITH SEIZURES INDUCED BY CORIARIA LACTONE

目的观察褪黑素(melatonin,MT)对马桑内酯(coriaria lactone,CL)致痫大鼠海马及皮质内TNF-α水平的影响,探讨其抑制癫痫的作用机制。方法60只健康雄性SD大鼠随机分为4组(每组15只),分别为A组:生理盐水对照组(NS组);B组:马桑内酯致痫组(CL组):C组:褪黑素+马桑内酯组(MT+CL组):D组:Luzidole+褪黑素+马桑内酯组(Luz+MT+CL组)。观察并记录大鼠行为学改变,用免疫组织化学方法检测大鼠海马及皮质内TNF-α含量的变化。用实时荧光定量PCR的方法检测大鼠海马内TNF-αmRNA含量的变化。结果行为学观察,NS组无痫样发作,CL组和Luz+MT+CL组痫样发作重(Ⅲ-Ⅴ级),MT+CL组无或仅有轻微发作(0-Ⅱ级);免疫组织化学观察,与正常对照组比较,CL组和Luz+MT+CL组大鼠海马及皮质内TNF-α含量均明显增高(P<0.05):与CL组和Luz+MT+CL组比较,MT+CL组TNF-α含量明显降低(P<0.05)。实时荧光定量PCR结果显示,与正常对照组比较,CL组和Luz+MT+CL组大鼠海马TNF-αmRNA含量均明显增高(P<0.05);与CL组和Luz+MT+CL组比较,MT+CL组大鼠海马TNF-αmRNA含量明显降低(P<0.05):结论褪黑素能明显地抑制马桑内酯引起的致痫作用,其机制可能与影响海马及皮质内TNF-α水平有关。

Objective To observe the effects of melatonin on the TNF-α level in hippocampus and cortex of rats with seizures induced by CL. Methods Sixty male adult SD rats were randomly divided into 4 groups （ 15 rats each） ： control, CL, melatonin intervention, and luzidole＋ melatonin＋ CL. The behavior of rats was observed and recorded. The TNF-α expression in hippocampus and cortex was examined with immunohistochemistry, and the mRNAlevel in the hippocampus, with real-time fluorescent quantitative PCR（FQ- PCR）. Results The control group showed no seizure activity, and the melatonin intervention group showed no or weak seizure activity, but the other two groups had severe seizure activities. The results of immunohistochemistry showed that the level of TNF-α in hippocampus and cortex in the CL group and luzidole＋ melatonin ＋ CL group was much stronger than that of the control group（P〈0.05）, and the level of TNF-α in melatonin group was much lower than that of the CL group and luzidole＋ melatonin＋ CL group（P〈0.05）. The results of FQ-PCR showed that the level of TNF-α mRNA in the hippocampus of the CL group and luzidole＋ melatonin ＋ CL group was much higher than that of the control group（P〈0.05）, and the level of TNF-α mRNA in the melatonin group was much lower than that of the CL group and luzidole＋ melatonin＋ CL group （P〈0.05）.Conclusion Melatonin can inhibit the CL-induced seizure activities by down-regulating TNF-α.