新生大鼠缺氧缺血性脑损伤GDNF表达水平的动态变化及托吡酯调控机制的实验研究

Study of the dynamic expression of glial cell line-derived neurotrophic factor and the Topamax regulation mechanism with hypoxic-ischemic brain damage

【目的】探讨新生大鼠缺氧缺血性脑损伤(hypoxic-ischemic brain damage,HIBD)后胶质细胞源性神经营养因子(glial cell line-derived neurotrophic factor,GDNF)表达水平的动态变化及不同剂量托吡酯(topamax,TPM)干预对其表达的影响和机制。【方法】120只新生7日龄大鼠随机分为假手术组(Ⅰ)、单纯缺氧缺血组(Ⅱ)及[50(Ⅲ)、100(Ⅳ)1、50 mg/kg(Ⅴ)]TPM治疗组,建立HIBD动物模型,应用HE染色、免疫组织化学等方法,观察HIBD后不同时期脑组织病理学变化,GDNF的动态表达变化及TPM不同给药剂量对其表达的影响。【结果】①Ⅲ、Ⅳ、Ⅴ组脑组织损伤较Ⅱ组明显减轻,其减轻程度与用药剂量呈正相关。②GDNF的表达于缺氧缺血后12 h出现,3 d达高峰;Ⅲ、Ⅳ、Ⅴ组GDNF在各时相点上的增加较Ⅱ组差异有显著性(各时相点相比P值均<0.05),Ⅲ、Ⅳ、Ⅴ组之间GDNF的增加有显著性(各时相点相比P值均<0.05)。【结论】①HIBD后GDNF表达变化存在一定的时序性规律;②TPM对神经元的保护作用与剂量呈正相关;③TPM脑保护作用机制之一通过增加胶质细胞分泌GDNF实现。

【Objective】 To study of the dynamic expression of glial cell line-derived neurotrophic factor（GDNF）and the Topamax regulation mechanism after hypoxic-ischemic brain damage（HIBD）. 【Methods】 One hundred and twenty newborn Wistar rats aged 7 days were randomly divided to sham operation groupⅠ,pure hypoxic-ischemic groupⅡ,[50（Ⅲ）,100（Ⅳ）,150 mg/kg（Ⅴ）] Topamax administration group.By establishing of the dynamic expression of glial cell line-derived neurotrophic factor and the Topamax neonate rats HIBD animal modals,applying HE drum dyeing,immunocytochemistry to observe the dynamic expression of cerebral cortex GDNF after HIBD during different treatment groups. 【Results】 ①Brain tissue damage of Topamax treatment relive obviously compared to pure hypoxic-ischemic group,and the bigger dose,the better effect.② The express of GDNF began to rise at 12 hours after HIBD,reaching the peak at the third day during Topamax administration groups and pure hypoxic-ischemic group;the GDNF expression of different dose Topamax treatment groups increased significantly compared to effecthypoxic-ischemic group at same time（P〈0.05）,and there was statistical significance among different dose Topamax treatment groups（P〈0.05）. 【Conclusions】 ①The expression of GDNF reaches the peak at third days after HIBD.②The bigger medicine dose,the better protection effect to brain.③One mechanism of Topamax brain protection action through increasing the glial cell to excrete GDNF to implement.