老年慢性肾衰大鼠心肌缺血预处理后胎盘生长因子的表达及其意义

Expression of placental growth factor after myocardial ischemic preconditioning in senior rats with chronic renal failure and its potential role

目的观察老年慢性肾衰大鼠经过心肌缺血预处理(ischemic preconditioning,IPC)后心肌组织胎盘生长因子(placental growth factor,Pl GF)的表达,探讨Pl GF在老年慢性肾衰大鼠心肌损伤修复中可能的作用。方法 20月龄雄性SD大鼠16只,全部进行肾大部分切除(Platt法)制备慢性肾衰模型,随即分成IPC组和假手术组,每组8只。IPC组:结扎冠状动脉前降支使其缺血6 min,随后再灌注6 min,反复4次;假手术(sham)组:开胸操作同IPC组,但不阻断冠脉血流。术后12 h,麻醉后取两组大鼠心脏组织,分别用Western blot及免疫组化法检测Pl GF在心肌组织中蛋白表达水平。结果 Western blot方法测定IPC组中边缘区心肌组织中、缺血区域心肌组织中Pl GF表达水平均较假手术组及IPC组非缺血区明显增高(P<0.01)。免疫组化染色显示IPC组心肌组织中Pl GF表达水平较假手术组明显增高(P<0.01)。结论经IPC处理后,老年慢性肾衰大鼠心肌组织中Pl GF表达增高,提示IPC在老年慢性肾衰大鼠中Pl GF可能在缺血心肌保护过程中的一个重要作用。

Objective To observe the expression of placental growth factor（ Pl GF） after myocardial ischemic preconditioning（ IPC） in rats with chronic renal failure（ CRF）,and to explore the potential protective role of placental growth factor in myocardial damage repair of senior rats with CRF. Methods Sixteen senior rats（ 20 months old） underwent 5/6 nephrectomy（ Platt method）,then were randomly divided into IPC group（ n = 8） and sham group（ n = 8）. The rats were given LAD ligation for 6 min and reperfusion for 6 min,and then repeated four times in IPC group. The rats only underwent thracotomy but no blood flow blocking in sham group. Rat hearts were collected at 12 h after surgery to detect the expression of Pl GF protein by Western blot and immunohistochemistry. Results Western blot results showed the expression level of placental growth factor protein in peri-ischemia area and ischemic area at 12 h after IPC was significantly higher in IPC group than in sham group（ P〈0. 01）. Immunohistochemical staining revealed that the expression level of placental growth factor protein at 12 h after IPC was significantly higher in IPC group than in sham group（ P〈0. 01）. Conclusion The expression level of placental growth factor increases in senior CRF rats after IPC,which suggests that placental growth factor might be a critical factor in the protective process of IPC to ischemic heart in senior rats with CRF.