肢体缺血后代偿性血管新生及相关基因表达的动态变化和意义

The Dynamic Changes and Significance of the Compensatory Angiogenesis and Related Gene Expression in Muscle After Limb Ischemia

目的探讨肢体缺血后代偿性血管新生及相关基因表达的动态变化和意义。方法股动脉结扎法建立裸鼠肢体缺血模型,分别于术后3天及术后1、2、3、4周观察裸鼠肢体缺血的改变,应用苏木素-伊红染色和CD34免疫组织化学染色观察缺血肌肉组织形态学的改变,应用Western Blotting和逆转录聚合酶链反应检测低氧诱导因子1α、肝细胞生长因子和血管内皮生长因子蛋白和基因在缺血肌肉中表达的动态变化。结果裸鼠肢体坏疽于术后1~2周最为严重,至术后3~4周时有所改善。缺血后的肌肉纤维萎缩、变形,3~4周时逐渐好转。微血管数于缺血后2周时最多。低氧诱导因子1α和肝细胞生长因子的基因表达于缺血后3天时最为强烈,血管内皮生长因子的基因表达于缺血后1周时达高峰,至缺血后3~4周时,各基因的表达均接近正常对照。结论肢体缺血发生后,低氧诱导因子1α、肝细胞生长因子和血管内皮生长因子基因表达的变化介导了短暂的血管新生过程,但微血管的生成数量有限,尚不足以代偿肢体缺血的状态。

Aim To discuss the dynamic changes and significance of the compensatory angiogenesis and related gene expression in muscle after limb ischemia.Methods Femoral artery ligation method was used to establish nude mice limb ischemia model.3 days,1,2,3 and 4 weeks after limb ischemia,nude mice limb ischemic changes were observed respectively.Hematoxylin-Eosine staining and CD34 immunohistochemical staining were used to observe ischemic morphological changes in muscle tissue.The application of Western Blotting and reverse transcription polymerase chain reaction detection of hypoxia inducible factor 1α（HIF-1α）,hepatocyte growth factor（HGF） and vascular endothelial growth factor（VEGF） was used to observe the dynamic changes of gene expression in ischemic muscle.Results Nude mice limb gangrene was the most serious in 1～2 weeks after ischemia and improved 3～4 weeks after.After the limb ischemia,muscle fibers shrink and deformation in 3～4 weeks were getting better.The microvascular count was the highest in 2 weeks after limb ischemia.The gene expression of HIF-1α and HGF was the strongest in 3 days after limb ischemia,VEGF gene expression reached a peak at 1 week end.In 3～4 weeks after limb ischemia,all the gene expression were close to normal.Conclusion The short-term process of angiogenesis was mediated by HIF-1α,HGF and VEGF gene expression after the limb ischemia,but a limited number of capillary formation was not enough to compensate the state of limb ischemia.