摘要
目的 观察重组人促红细胞生成素（rhEPO）对猪缺血心肌的血管生成效应及其作用机制.方法 选用12只6～8个月的巴马小型猪,应用胸腔镜微创技术将血管缩窄环放置于回旋支,利用心电图、冠状动脉造影评估回旋支闭塞或相应心肌缺血的程度,建立猪慢性心肌缺血模型.治疗组6只分别于建模后第1、3、7、14、21天皮下注射6 000 U rhEPO,对照组6只于同样的时间点皮下注射等量的生理盐水.用ELISA法检测治疗前及治疗后第3、7、14、21天血清中血管内皮生长因子（VEGF）蛋白的分泌;28 d后行超声心动图检测左心室功能变化,行冠状动脉造影进行回旋支血流分级;取各组心肌,采用Western blot法检测VEGF、磷酸化蛋白激酶B（p-Akt）、磷酸化细胞外信号调节激酶（p-Erk）的表达,免疫组化染色法检测毛细血管和小动脉生成情况.结果 rhEPO治疗后第3天血清VEGF分泌水平达到高峰,至第28天时回落至接近基础水平;rhEPO治疗后,治疗组心功能较对照组改善明显;Western blot检测结果显示rhEPO治疗后1个月,VEGF、p-Akt和p-Erk蛋白表达水平都有不同水平的升高,其相对表达量分别是对照组的2.5倍、1.1倍和1.5倍（t=37.721、10.907、12.957,P均=0.000）.治疗组心肌毛细血管密度和小动脉密度分别为（944±98）％/mm2和（73±13） ％/mm2,对照组分别为（569±102） ％/mm2和（45±10）％/mm2,差异均有统计学意义（=4.214、2.869,P=0.016、0.023）.结论 rhEPO可促进猪缺血心肌血管的生成,其机制可能是通过上调p-Akt、p-Erk的表达实现的.
Objective To investigate the effect and mechanism of recombinant human erythropoietin （rhEPO） on angiogenesis in chronic ischemic porcine myocardium. Methods A ameroid constrictor was placed around the proximal circumflex branch of the left coronary artery in 12 Bama miniatures＇ swine artery by thoracoscopy. Electrocardiogram and coronary angiography were used to confirm the establishment of myocardial ischemia. The animals were divided into rhEPO treatment group （n = 6） and negative control group （n =6）. Treatment group received subcutaneous injection of rhEPO at 1,3,7,14,21 days, control group received saline. The expression of vascular endothelial growth factor （VEGF） in serum was assessed by ELISA. Uhrasonography and coronary angiography were assessed 28 days after therapy. Western blot was used to detect the expression of VEGF, phosphorylated protein kinase B （p-Akt） and phosphorylated extracellular signal regulated kinases （p-Erk）. The degree of angiogenesis was assessed by immunohistochemical analysis. Results Serum VEGF rose significantly in both control and treatment groups, peaking at 3 days and then returning to the near-baseline level at 28 days, but the two groups showed no significant difference at each time point （P 〉 0. 05 ）. Echocardiographic measurements showed that the left ventricular systolic function of animals in treatment group increase significantly after rhEPOtherapy, the expression levels of VEGF, p-Akt and p-Erk had markedly increased, which resulted in a 2. 5- fold increased of VEGF, 1.1-fold increased of p-Akt, 1.5-fold increased of p-Erk （ t = 37. 721, 10. 907, 12. 957, all P = 0. 000）. there were significant increase in capillary density and arteriole density in the two groups （（944±98） %/mm2vs. （569＋102） %/mm2, （73±3） %/mm2 vs. （45±10） %/mm2, t= 4. 214, 2. 869, P = 0. 016, 0. 023）. Conclusions rhEPO can promote angiogenesis and arteriogenesis and improve the left ventricular systolic function in porcine model of chronic myocardial ischemia. The potential menchanism is to up-regulated the expression of p-Akt and p-Erk.
出处
《中华外科杂志》
CAS
CSCD
北大核心
2014年第5期366-369,共4页
Chinese Journal of Surgery
基金
浙江省科技计划资助项目（2011C37083）
