脑脉通对老龄大鼠脑缺血/再灌注微血管生成及bFGF、TGF表达的影响

Effect of Naomaitong on cerebral angiogenesis and expressions of TGF, bFGF after cerebral ischemia/reperfusion in aged rats

目的:从碱性成纤维生长因子(bFGF)、转化生长因子(TGF-β1)表达方面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,运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bFGF、TGF-β1与TGF-β1mRNA表达。结果:模型组I/R6d、12d MVD低于假手术组(P<0.05,P<0.01),I/R1d血管场面积高于假手术组(P<0.05);脑脉通组I3h、I/R1d、3d、12d MVD和I3h、I/R3d、6d、12d血管场面积均较模型组同时间点升高(P<0.05,P<0.01);与尼莫地平组比较,脑脉通组I/R12d MVD增加(P<0.01),I3h血管场面积增大(P<0.01)。脑脉通组MVDI3h明显增加,I/R1d达到峰值,I/R1d后MVD开始下降,I/R6d降至最低,至I/R12d MVD又明显增加;血管场面积I3h有明显增加,I/R1d降至最低,I/R3d时有所升高,至I/R6d再次降低,随后再次升高,I/R12d恢复至I/R3d时水平。模型组各时间点bFGF、TGF-β1表达均较假手术组增强(P<0.01),I/R1dTGF-β1 mRNA表达较假手术组增高(P<0.01),I/R12dTGF-β1 mRNA表达较假手术组降低(P<0.01);脑脉通组I3h、I/R1d、6d、12d bFGF表达,各时间点TGF-β1表达和I/R3d、6d、12dTGF-β1 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I/R 3d bFGF表达减弱(P<0.01),其余各时间点表达均增强(P<0.01),I3h、I/R6d、12d TGF-β1表达与I/R3d、6d TGF-β1 mRNA表达增强(P<0.05,P<0.01),I/R3dTGF-β1表达与I3hTGF-β1 mRNA表达减弱(P<0.01)。脑脉通组bFGF、TGF-β1表达均于I3h开始增强,持续升高至I/R6d达峰值,I/R6-12d表达稍有减弱;TGF-β1 mRNA表达I3h开始增强,持续至I/R3d达到峰值,I/R3-12d表达逐步下降。结论:脑脉通促进老年脑缺血/再灌注微血管生成机制与其提高bFGF和TGF-β1表达有关。

Objective： To reveal the mechanism of promotive effect of Naomaitong on cerebral angiogenesis after cerebral ischemia/ reperfusion in aged rats through the expressions of TGF and bFGF. Methods： Aged masculine SD rats were randomly divided into sham operated group, model group, Nimodipine group and Naomaitong group. To examine the microvessel density （MVD） of brain tissue, sum area of lumens, the expressions of bFGF, TGF-β1 and TGF-β1 mRNA by immunohistochemistry and hybridization in situ etc. Results： Compared with model group at the same time point, both MVD （I 3h, I/R 1d, 3d, 12d） and sum area of lumens （I 3h, I/R 3d, 6d, 12d） in Naomaitong group were increased （P〈0.05, P〈0.01）. MVD in Naomaitong group began to increase notably at I 3h, peaking at I/R 1d, then started to decreased after I/R 1d, with a lowest level at I/R 6d, obviously increased again at I/R 12d. Sum area of lumens in Naomaitong group also increased remarkably at I 3h, while with a lowest level at I/R 1d, then increased a little at I/R 3d, decreased again at I/R 6d, stepped up once again subsequently, finally recovered to the level ofI/R 3d at I/R 12d. Compared with model group at the same time point, expressions of bFGF （I 3h, I/R 1d, 6d, 12d）, TGF-β1 （all time points） and TGF-β1 mRNA （I/R 3d, 6d, 12d） in Naomaitong group were increased （P〈0.01）. Expressions of bFGF, TGF-β1 in Naomaitong group all began to increase at I 3h, lasted to enhance, then peaking at I/R 6d, finally decreased slightly among I/R 1d-12d. Expressions of TGF-β1 mRNA in Naomaitong group began to increase at I 3h, peaking at I/R 3d, decreased gradually among I/R 3-12d. Conclusion： Naomaitong can promote angiogenesis after cerebral ischemia/ reperfusion in the aged, the mechanism of which may be related to the enhanced expressions of bFGF, TGF-β1, TGF-β1 mRNA that Naomaitong induced.