银杏叶提取物对局灶性脑缺血大鼠血管内皮因子表达的影响

Effects of Ginkgo Biloba extract powder on expression of VEGF in brain tissue after focal cerebral infarction in rats

目的探讨银杏叶提取物对大鼠局灶性脑缺血后神经行为及血管内皮因子(VEGF)表达的影响。方法采用线栓法制备局灶性脑缺血大鼠模型,将24只造模成功的SD大鼠随机分为模型组及银杏叶提取物低、中、高剂量组,每组6只,另选取正常大鼠6只作为假手术组。银杏叶提取物低、中、高剂量组分别给予银杏叶提取物注射液0.9,1.8,2.7 m L/100 g灌胃,假手术组及模型组给予1.8 m L/100 g生理盐水灌胃,均1次/d,连续14 d。通过平衡木实验评价大鼠的神经行为学改变,HE染色观察大鼠脑组织形态学变化,采用逆转录-聚合酶链式反应(RT-PCR)和免疫组织化学法检测大鼠脑内VEGF mRNA以及蛋白的表达情况。结果灌胃7 d和14 d后,银杏叶提取物低、中、高剂量组的平横木实验测试评分均明显高于模型组(P均<0.05),且银杏叶提取物中剂量组明显高于低剂量组和高剂量组(P均<0.05);HE染色显示银杏叶提取物能改变脑组织缺血区的组织形态;模型组VEGF mRNA及蛋白表达量均明显高于假手术组(P均<0.05),银杏叶提取物低、中、高剂量组VEGF mRNA及蛋白表达量均明显高于模型组(P均<0.05),且银杏叶提取物中剂量组VEGF mRNA及蛋白表达量均明显高于低剂量组和高剂量组(P均<0.05)。结论银杏叶提取物能够改善局灶性脑缺血大鼠的神经功能,可能与上调大鼠脑组织中VEGF mRNA及蛋白的表达有关;银杏叶提取物对缺血性脑损伤的改善程度与给药剂量有关。

Objective It is to observe the effects of Ginkgo Biloba extract powder on neurobehavior and expression of vascular endothelial growth factor（ VEGF） mRNA and protein in brain tissue of rats after focal cerebral infarction. Methods The ischemic models were established with line embolism method. 24 successful modeling Sprague- Dawley（ SD） rats were randomly divided into model group,Ginkgo Biloba extract powder groups（ low,middle and high dosage）,each group had 6 rats,and 6 normal rats were selected as sham operation group for comparison. Low,middle and high dosage of Ginkgo Biloba extract groups were given Ginkgo Biloba extract injection 0. 9,1. 8,2. 7 m L /100 g respectively by lavage,while sham operation group and model group were given normal saline by lavage once per day. All the treatments lasted for 14 days. Beam walking test was adopted to evaluate the SD rat ＇s neural behavior and HE staining was used to observe the rat brain morphological changes.VEGF mRNA and proteins expression were measured by reverse transcription- polymerase chain reaction（ RT- PCR） and immunohistochemical methods respectively. Results The scores of Ginkgo Biloba extract powder groups（ low,middle,high dosage） were respectively higher than that in model group after 7 and 14 days＇ treatment（ P 0. 05）,and the scores in middle dosage group were higher than that in low or high dosage groups（ P 0. 05）. The result of HE staining showed that Ginkgo Biloba extract powder could change the brain morpholody of rats. The expressions of VEGF mRNA and protein in model group was higher obviously than that in sham operation group（ P 0. 05）,the expressions of VEGF mRNA and protein in Ginkgo Biloba extract powder groups（ low,middle,high dosage） were respectively higher than that in model group（ P 0. 05）,and the expression in middle dosage group was higher than that in low or high dosage groups（ P 0. 05）. Conclusion Ginkgo Biloba extract powder could improve neurogenic function and up- regulate the expressions of VEGF in rats with focal cerebral ischemia,which may be a main mechanism of its neuroprotection against cerebral ischemia injury,and the improving effects were related with therapy dosage.