Banbury J, Siemionow M, Porvasnik S, Petras S, Browne E
Department of Plastic and Reconstructive Surgery, Cleveland Clinic Foundation, Ohio 44195, USA.
Plast Reconstr Surg. 2000 Dec;106(7):1541-6. doi: 10.1097/00006534-200012000-00015.
Vascular endothelial growth factor (VEGF), a potent endothelial mitogen, is secreted in ischemic tissue and plays a pivotal role in angiogenesis. We studied whether VEGF administered to a rat muscle flap at the time of ischemia induction would increase microcirculatory flow to the flap. The cremaster muscle flap was isolated on its neurovascular pedicle. Ischemia was induced by clamping the vascular pedicle, and 0.2 ml of either VEGF (0.1 microg) or vehicle (phosphate-buffered saline) was immediately infused into the muscle. After 4 or 6 hours, the clamps were released, and the cremaster was placed in a pocket in the medial thigh for 24 hours. The muscle was then dissected, and microcirculatory measurements were made under intravital microscopy. Six animals were used in each of the four groups. All flaps exposed to 6 hours of ischemia, the duration considered to be critical ischemia, had no significant microcirculatory flow, regardless of treatment with VEGF. In the 4-hour ischemia group, or subcritical ischemia group, red blood cell velocity in arterioles was 14 mm/sec in muscles treated with VEGF and 9 mm/sec in controls (p = 0.02), and capillary flow was 7 per high-power field in muscles treated with VEGF versus 2 per high-power field in controls (p = 0.0005). Thus, VEGF did not alter microcirculatory flow in a muscle flap exposed to critical ischemia, but it did enhance flow to a flap exposed to subcritical ischemia.
血管内皮生长因子（VEGF）是一种强效的内皮细胞促分裂原，在缺血组织中分泌，在血管生成中起关键作用。我们研究了在诱导缺血时给予大鼠肌皮瓣VEGF是否会增加其微循环血流量。将提睾肌皮瓣连同其神经血管蒂分离出来。通过钳夹血管蒂诱导缺血，然后立即向肌肉中注入0.2 ml的VEGF（0.1μg）或赋形剂（磷酸盐缓冲盐水）。4或6小时后松开夹子，将提睾肌置于大腿内侧的袋中24小时。然后解剖肌肉，在活体显微镜下进行微循环测量。四组中每组使用6只动物。所有暴露于6小时缺血（这一持续时间被认为是临界缺血）的皮瓣，无论是否用VEGF治疗，均无明显的微循环血流。在4小时缺血组或亚临界缺血组中，用VEGF治疗的肌肉中微动脉内的红细胞速度为14 mm/秒，对照组为9 mm/秒（p = 0.02），用VEGF治疗的肌肉中毛细血管血流为每高倍视野7个，而对照组为每高倍视野2个（p = 0.0005）。因此，VEGF并未改变暴露于临界缺血的肌皮瓣的微循环血流，但确实增加了暴露于亚临界缺血的皮瓣的血流。
