Objective To reveal the promoting mechanism of Naomaitong on cerebral angiogenesis after cerebral ischemia/reperfusion (I/R) in aged rats based on the expressions of fetal liver kianse-1 (Flk-1). Methods Male and aged SD rats were randomly divided into the sham-operation group, model group, nimodipine group and Naomaitong group. The microvessel density (MVD) of brain tissue, area of vascular field, and expressions of Flk-1 and Flk-1-mRNA were detected by using immunohistochemistry and hybridization in situ. Results Compared with the model group at the same time point, both MVD [ ischemia (I) for 3 h, and I/R for 1 d, 3 d and 12 d] and area of vascular field ( I for 3 h, and I/R for 3 d, 6 d and 12 d) in the Naomaitong group were increased (P ＜0. 05, P ＜0. 01). Compared with the nimodipine group, both MVD (I/R for 12 d) and the area of vascular field (I for 3h) in Naomaitong group were increased (P ＜0. 01 ). In the model group MVD lasted to descend from I for 3 h to I/R for 12 d, the are of vascular field reached peak after I/R for 1 d, then decreased quickly, and reached the lowest level after I/R for 12 d. The area of vascular field (I/R for 1 d) reached peak, then decreased quickly and to the lowest level after 12 days. In the Naomaitong group MVD increased significantly after I for 3 h, reached peak after I/R for 1 d, then started to decrease after, reached the lowest level after I/R for 6 d, and increased significantly after I/R for 12 d, and the area of vascular field increased significantly after I for 3 h, decreased to the lowest level after I/R for 1 d, increased a little after L/R for 3 d, decreased again after I/R for 6 d, and then increased again and recovered to the level of I/R for 3 d after I/R for 12 d. The expressions of Flk-1 in the Naomaitong group at all time points increased compared with the model group (P ＜ 0. 05, P ＜ 0. 01 ). Compared with the nimodipine group, expressions of Flk-1 in the Naomaitong group after I/R for 1 d, 6 d and 12 d increased (P ＜0. 05, P ＜ 0. 01 ), while decreased after I/R for 3 d (P ＜0. 01 ). In the model group the expression of Flk-1 began to increase after I for 3 h, reached peak after I/R for 1 d, and decreased rapidly after I/R from 1 d to 12 d. In the Naomaitong group the expression of Flk-1 performed better after I for 3 h, reached peak after L/R for 3 d, then decreased a little, but still kept a higher level after I/R for 12 d. Compared with the model group at the same time point, expression of Flk-1-mRNA increased ( P ＜ 0. 01 ) in the Naomaitong group, and increased after I/R for 6 d and 12 d ( P ＜0. 01 ) compared with the nimodipine group. In the model group the expression of Flk-1-mRNA reached peak after I/R for 1 d and decreased fast after I/R from I d to 12 d. In the Naomaitong group the expression of FIk-1-mRNA was higher after I for 3 h, reached peak after L/R for 1 d, then decreased gradually, and still kept a higher level after I/R for 12 d. Conclusion Naomaitong can promote angiogenesis after cerebral ischemia/ reperfusion in the aged, and the mechanism of which may be related to the increase of expressions of Flk-1 and Flk-1-mRNA.%目的 从胚胎肝激酶-1(Flk-1)因子表达变化揭示脑脉通促进老龄大鼠脑缺血/再灌注血管生成的作用机制.方法 将 SD雄性老龄大鼠随机分为假手术组、模型组、尼莫地平组、脑脉通组,采用免疫组化和原位杂交等方法测定脑微血管密度(MVD)、血管场面积以及Flk-1的蛋白与mRNA表达.结果 脑脉通组缺血3 h和缺血/再灌注1、3、12 d的MVD,缺血3 h和缺血/再灌注3、6、12 d血管场面积,均较模型组升高(P<0.05,P<0.01);与尼莫地平组比较,脑脉通组缺血/再灌注12 d MVD增加(P<0.01),缺血3 h血管场面积增大(P<0.01).模型组MVD自缺血3 h持续下降至缺血/再灌注12 d;血管场面积缺血/再灌注1 d达到峰值,然后迅速下降,至12 d降至最低.脑脉通组MVD 缺血3 h明显增加,缺血/再灌注1 d达到峰值,然后开始下降,缺血/再灌注6 d降至最低,至12 d又明显增加;血管场面积缺血3 h有明显增加,缺血/再灌注1 d降至最低,3 d时有所升高,至6 d再次降低,随后再次升高,至12 d恢复至缺血/再灌注3 d时水平.脑脉通组各时间点Flk-1表达均较模型组增强(P<0.05,P<0.01);与尼莫地平组比较,脑脉通组缺血/再灌注1、6、12 d Flk-1表达增强(P<0.05,P<0.01),缺血/再灌注3 d Flk-1表达减弱(P<0.01).模型组Flk-1表达于缺血3 h开始增强,缺血/再灌注1 d达到峰值,1～12 d表达迅速减弱;脑脉通组Flk-1于缺血3 h有较强表达,缺血/再灌注3 d达到峰值,此后表达稍有减弱,至12 d表达仍处于较高水平.脑脉通组各时间点Flk-1 mRNA表达水平均较模型组增强(P<0.01);与尼莫地平组比较,脑脉通组缺血/再灌注6、12 d Flk-1 mRNA表达水平增强(P<0.01).模型组Flk-1 mRNA表达于缺血/再灌注1 d最强,1～12 d迅速下降;脑脉通组Flk-1 mRNA缺血3 h即有较高表达,缺血/再灌注1 d达峰值,此后逐渐下降,至12 d表达仍能维持一个较高水平.结论 脑脉通可促进老年大鼠脑缺血/再灌注微血管生成,其机制可能与提高Flk-1及其mRNA表达有关.
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