Türegün M, Güdemez E, Newman P, Zins J, Siemionow M
Department of Plastic and Reconstructive Surgery at Gülhane Military Medical Academy and Medical School, the Blood Research Institute, Cleveland, Ohio, USA.
Plast Reconstr Surg. 1999 Sep;104(4):1033-40. doi: 10.1097/00006534-199909020-00021.
Several lines of evidence show that platelet endothelial cell adhesion molecule-1 (PECAM-1), a component of endothelial cell junctions, is required for leukocyte transmigration through endothelial cell monolayers. Polymorphonuclear leukocytes play an important role in ischemia-reperfusion injury. We sought to determine whether administering an anti-PECAM-1 antibody would prevent or attenuate ischemia-reperfusion injury in a rat cremaster muscle flap injury model. Eighteen male Sprague-Dawley rats were divided into three groups. Group I (control): Cremaster muscle island flaps were dissected for baseline measurements of eight indicators: numbers of rolling, sticking, and transmigrating neutrophils, numbers of rolling and sticking lymphocytes, number of perfused capillaries, endothelial edema, and vessel permeability. Group II: The prepared cremaster flap was subjected to 4 hours of ischemia and 24 hours of reperfusion. Group III: The muscle flap was subjected to ischemia and reperfusion as in group II, and anti-PECAM-1 antibodies (1 mg/kg) were injected subcutaneously 15 minutes before reperfusion. Blood vessels were observed in vivo under an intravital microscopy system. Microvascular permeability was made visible with injected fluorescein isothiocyanate-labeled albumin and evaluated with Kontron Elektronik computer software. The ischemia-reperfusion-alone group (group II) presented a 225-percent increase in the activation of sticking leukocytes (2.4 +/- 0.4 to 7.8 +/- 0.8, p < 0.05) (p < 0.01). This leukocyte activation was reduced by 83 percent following anti-PECAM-1 monoclonal antibody treatment (1.3 +/- 0.5 per 100 microm) (p < 0.01). At 24 hours, endothelial injury in group II was confirmed by a 4-fold increase in the number of transmigrating leukocytes into the interstitial space (7.6 +/- 1.2 per field versus 1.9 +/- 0.4 per field in controls). This phenomenon was reduced by 85 percent following anti-PECAM-1 monoclonal antibody treatment (1.1 +/- 0.2 per field) (p < 0.01). Analysis showed that the number of flowing capillaries was 67 percent lower in group II (6.8 +/- 0.3 to 2.2 +/- 0.7, p < 0.01). Anti-PECAM-1 antibody treatment caused a 2.5-fold increase in this number (5.6 +/- 0.5, p < 0.01). Microcirculatory permeability index showed a 180-percent increase in group II (p < 0.05) when compared with baseline values. This increased albumin leakage was effectively attenuated by antibody treatment (p < 0.05). Blocking the action of PECAM-1 in vivo by administering monoclonal antibodies significantly attenuated ischemia-reperfusion injury, presumably by inhibiting transendothelial migration of neutrophils and by increasing capillary perfusion at a muscle flap microcirculatory level.
多条证据表明，血小板内皮细胞黏附分子-1（PECAM-1）作为内皮细胞连接的一个组成部分，是白细胞穿过内皮细胞单层进行迁移所必需的。多形核白细胞在缺血再灌注损伤中起重要作用。我们试图确定给予抗PECAM-1抗体是否能预防或减轻大鼠提睾肌皮瓣损伤模型中的缺血再灌注损伤。18只雄性Sprague-Dawley大鼠被分为三组。第一组（对照组）：解剖提睾肌岛状皮瓣，用于测量八项指标的基线值：滚动、黏附及迁移的中性粒细胞数量、滚动及黏附的淋巴细胞数量、灌注毛细血管数量、内皮水肿及血管通透性。第二组：制备的提睾肌皮瓣经历4小时缺血和24小时再灌注。第三组：肌皮瓣如第二组一样经历缺血和再灌注，并在再灌注前15分钟皮下注射抗PECAM-1抗体（1mg/kg）。在活体显微镜系统下对血管进行体内观察。通过注射异硫氰酸荧光素标记的白蛋白使微血管通透性可见，并使用Kontron Elektronik计算机软件进行评估。单纯缺血再灌注组（第二组）黏附白细胞的活化增加了225%（从2.4±0.4增至7.8±0.8，p<0.05）（p<0.01）。抗PECAM-1单克隆抗体治疗后，这种白细胞活化减少了83%（每100微米1.3±0.5）（p<0.01）。在24小时时，第二组内皮损伤通过迁移至间质空间的白细胞数量增加4倍得以证实（每视野7.6±1.2，而对照组为每视野1.9±0.4）。抗PECAM-1单克隆抗体治疗后，这种现象减少了85%（每视野1.1±0.2）（p<0.01）。分析显示，第二组中流动毛细血管数量减少了67%（从6.8±0.3降至2.2±0.7，p<0.01）。抗PECAM-1抗体治疗使该数量增加了2.5倍（5.6±0.5，p<0.01）。微循环通透性指数显示，与基线值相比，第二组增加了180%（p<0.05）。抗体治疗有效减轻了白蛋白渗漏增加的情况（p<0.05）。通过给予单克隆抗体在体内阻断PECAM-1的作用，显著减轻了缺血再灌注损伤，推测这是通过抑制中性粒细胞的跨内皮迁移以及在肌皮瓣微循环水平增加毛细血管灌注实现的。
