兔后肢动静脉短路诱导动脉生成过程中VEGF(A)及其受体Flk-1的表达

目的探讨兔后肢动脉生成过程中VEGF(A)及其受体Flk-1的表达特征。方法兔双侧股动脉结扎,并将一侧结扎的股动脉远侧端缝到伴行的静脉上造成动静脉短路,另一侧为对照组。一周后动物被处死。应用免疫荧光组织化学技术检测侧支血管中VEGF(A)及其受体Flk-1的表达。结果在正常血管,VEGF(A)没有表达,Flk-1只在内皮细胞上有微弱表达;对照侧,VEGF(A)和Flk-1在平滑肌细胞和内皮细胞的表达明显上调;在动静脉短路侧,VEGF(A)和Flk-1的表达显著增加,分别是对照侧的2·3倍和2倍。结论在侧支血管发育过程中,VEGF(A)及其受体Flk-1在平滑肌细胞和内皮细胞同时表达上调,在快速生长的侧支血管它们的表达更为显著,提示Flk-1的表达在VEGF促动脉生成作用中具有重要意义。

EXPRESSIONS OF VASCULAR ENDOTHELIAL GROWTH FACTOR A (VEGF) AND ITS RECEPTOR FLK-1 DURING ARTERIOGENESIS INDUCED BY ARTERIOVENOUS SHUNT IN RABBIT HIND-LIMBS

Objective To characterize the expression of VEGF (A) and its receptor, Flk-1, during arteriogenesis in the hind-limb of rabbits.Methods Acute bilateral femoral artery ligation was performed with two knots. Immediately following occlusion, an arteriovenous(AV) shunt was created unilaterally, between the distal femoral artery stump and the accompanying femoral vein. The simply ligated contralateral side was used as the control. The animals were sacrified after surviving for one week. The expression of VEGF (A) and its receptor in collateral vessels was studied by confocal immunofluorescence. Results In normal vessels,VEGF(A) staining was negative, and Flk-1 was very weakly present in the endothelium. In the control vessels VEGF(A) and its receptor Flk-1 were significantly induced in endothelial and smooth muscle cells. In the shunt side the induction of VEGF(A) and Flk-1 was more apparent, being 2.3-fold and 2-fold higher over those in the control side respectively. Conclusion VEGF(A) and Flk-1 are simultaneously upregulated in the endothelial and smooth muscle cells during arteriogenesis. The expression of VEGF(A) and Flk-1 ismore apparent in the rapid growing collateral vessels induced by AV-shunt, implying that Flk-1 plays an important role in collateral vessel growth promoted by VEGF.