兔缺血后肢内源性VEGF蛋白表达与侧支形成相关性研究

Endogenous VEGF Expression Related to Collateral Vessels Formation in Rabbit Ischemic Model

目的：探索缺血肢体代偿侧支形成过程中内源性ＶＥＧＦ蛋白表达的相应规律。方法：新西兰雄性白兔４０只，切除兔一侧后肢股浅动脉全长建立缺血模型，分为１天、３天、７天、１４天、２８天、５６天及９０天７个观察期（ｎ＝５）；另设对照组（ｎ＝５）。观察造模后小腿动脉压比率、动脉造影血管计数及缺血后肢肌组织毛细血管密度和内源性ＶＥＧＦ蛋白的变化。结果：造模后３天，缺血后肢骨骼肌中即有内源性ＶＥＧＦ蛋白表达，７天时达到高峰，２８天后逐渐减弱，而缺血区新血管发生也相应停滞。结论：内源性ＶＥＧＦ蛋白表达有其特定时限性，提示在其表达水平开始下降时，应考虑补充外源性ＶＥＧＦ。

Objective: To explore the relationship between endogenous VEGF protein expression and compensatory collateral formation in an ischemic model. Methods: Unilateral ischemic model of the lower extremity was produced by complete excision of the superficial femoral artery in 40 male New Zealand white rabbits. The animals were divided into groups of 5 animals each according to the time after the induction of limb ischemia(Day 1, 3, 7, 14, 28, 56 and 90). The other 5 animals served as the control group. Changes of the calf blood pressure ratio, the number of collateral vessels, the capillary density, as well as the endogenous VEGF protein expression were closely observed and evaluated. Results: In the ischemic limb, vascular endothelial cells expressed VEGF protein as early as in Day 3, and reached the peak value on Day 7. The expression of VEGF proteins decreased gradually after Day 28, angiogenesis of the ischemic region was inactivated accordingly. Conclusions: Endogenous VEGF protein expression in ischemic skeletal muscles fluctuates with time after production of ischemia. This suggests that exogeneous VEGF should be supplied when the expression starts to decline.