二甲基乙二酰基甘氨酸对跨区穿支皮瓣Choke Ⅱ区血管生成的影响机制研究

Effect of dimethyloxalylglycine on angiogenesis in Choke Ⅱ zone of cross-zone perforator flap and its mechanism

目的研究二甲基乙二酰基甘氨酸(dimethyloxalylglycine,DMOG)对跨区穿支皮瓣Choke Ⅱ区血管生成的影响及作用机制。方法将126只成年雄性SD大鼠随机分为DMOG组、YC-1组和空白对照组,每组42只。3组大鼠背部制作大小为12 cm×3 cm的跨区穿支皮瓣模型;于术前1 d、2 h及术后1、2、3 d分别腹腔注射DMOG(40 mg/kg)、YC-1(HIF-1α抑制剂,10 mg/kg)和等量生理盐水。术后观察各组大鼠皮瓣成活情况,7 d时测量皮瓣成活面积并计算皮瓣成活率,皮瓣透光实验、明胶-氧化铅血管造影及HE染色观察皮瓣Choke Ⅱ区血管生成情况,免疫组织化学染色及Western blot法检测皮瓣Choke Ⅱ区VEGF及HIF-1α表达;3、5、7 d ELISA法测定皮瓣Choke Ⅱ区VEGF和HIF-1α蛋白含量。结果术后7 d时DMOG组皮瓣远端未见明显坏死,空白对照组和YC-1组皮瓣均发生坏死且主要位于远端;DMOG组皮瓣成活率为90.28%±1.37%,高于YC-1组84.28%±1.45%及空白对照组85.83%±1.60%,差异有统计学意义(P<0.05)。DMOG组皮瓣Choke Ⅱ区血管较多且结构清晰、完整;YC-1组、空白对照组中Choke Ⅱ区血管较少且结构紊乱。DMOG组血管数量为(25.56±1.29)条/视野,高于YC-1组(7.38±0.54)条/视野及空白对照组(14.48±0.91)条/视野,差异有统计学意义(P<0.05)。术后3、5、7 d,DMOG组皮瓣Choke Ⅱ区HIF-1α、VEGF表达均高于其余两组,差异有统计学意义(P<0.05)。结论 DMOG能促进跨区穿支皮瓣Choke Ⅱ区血管生成,加速皮瓣早期血管化进程,改善微循环和血供,降低皮瓣缺血、缺氧损伤程度,提高成活率。

Objective To study the effect of dimethyloxalylglycine(DMOG) on angiogenesis in Choke Ⅱ zone of rats cross-zone perforator flaps and its mechanism. Methods One hundred and twenty-six adult male Sprague Dawley rats were randomly divided into DMOG group, YC-1 group, and control group, with 42 rats in each group. Crosszone perforator flap model with size of 12 cm×3 cm was made on the back of rats in the three groups. DMOG group was intraperitoneally injected with DMOG(40 mg/kg) at 1 day before operation, 2 hours before operation, and 1, 2, and3 days after operation;YC-1 group and control group were intraperitoneally injected with YC-1(10 mg/kg) and the same amount of normal saline at the same time points, respectively. The survival of flap was observed after operation. At 7 days after operation, the survival area of flap in each group was measured and the survival rate of flap was calculated. Flap transmittance test, gelatin-lead oxide angiography, and HE staining were used to observed the angiogenesis in the Choke Ⅱ zone of flaps in each group. Immunohistochemical staining and Western blot were used to detect the expressions of vascular endothelial growth factor(VEGF) and hypoxia-inducible factor 1α(HIF-1α) in Choke Ⅱ zone of flaps in each group. The expressions of VEGF and HIF-1α were also determined by ELISA at 3, 5, and 7 days. Results At 7 days after operation, there was no obvious necrosis at the distal end of the flap in DMOG group, while necrosis occurred in both the control group and YC-1 group, mainly located at the distal end. The flap survival rate of DMOG group was 90.28%±1.37%,which was significantly higher than that of YC-1 group(84.28%±1.45%) and control group(85.83%±1.60%)(P<0.05).DMOG group had more angiogenesis in Choke Ⅱ zone and the vascular structure was clear and complete. In YC-1 group and control group, the vessels in Choke Ⅱ zone was less and the vascular structure was disordered. The number of vessels was(25.56±1.29)/field in the DMOG group, which was significantly higher than that in the YC-1 group [(7.38±0.54)/field]and the control group [(14.48±0.91)/field](P<0.05). At 3, 5, and 7 days after operation, HIF-1α and VEGF expressions in Choke Ⅱzone of DMOG group were significantly higher than those in YC-1 group and control group(P<0.05).Conclusion DMOG can promote angiogenesis in Choke Ⅱ zone, accelerate the early angiogenesis of the flap, improve the microcirculation and blood supply in the potential zone of the flap, reduce the injury of flap ischemia and hypoxia, and increase the survival rate of the flap.