吡那地尔预处理对兔心脏缺血再灌注时心肌炎性反应的影响

Effect of pinacidil preconditioning on myocardial inflammatory response to ischemia-reperfnsion of isolated rabbit heart

目的 评价吡那地尔预处理对兔心脏缺血再灌注时心肌炎性反应的影响。方法 日本大耳白兔56只，随机分为4组：正常对照组（C组，n=8）、缺血再灌注组（I／R组，n=16）、吡那地尔预处理组（P组，n=16）和格列本脲组（G组，n=16）。建立离体心脏Langendorff再灌注模型，灌注充氧K—H液，待心率平稳10min时，C组取心肌组织，测定丙二醛（MDA）、补体C3a、细胞间粘附分子-1（ICAM-1）和细胞核NF—κBp65表达；I／R组继续灌注充氧K-H液40min；P组灌注充氧K-14液10min后，灌注10μmol／L充氧吡那地尔30min；G组灌注10μmol／L充氧格列本脲10min后，再灌注10μmol／L充氧吡那地尔30min。随后I／R组、P组和G组行全心缺血40min，再灌注充氧K—H液。I／R组、P组和G组分别于心率平稳10min、再灌注30、60min时取8个心脏，测定冠状静脉流出液中肌酸激酶（CK）活性和肿瘤坏死因子-α（TNF-α）浓度；再灌注60或120min时测定心肌组织MDA、补体C3a、ICAM-1及细胞核NF—κBp65表达。结果P组再灌注期间CK、TNF-α、MDA、补体C3a、ICA-1和NF—κBp65水平均明显低于其他各组（P〈0．05）。结论 吡那地尔预处理可减轻兔心脏缺血再灌注时心肌炎性反应，可能与ATP敏感性钾通道开放有关，从而对心肌产生保护作用。

Objective To evaluate the effect of pinacidil preconditioning on myocardial inflammatory response to ischemia-reperfusion （I/R） of isolated rabbit heart.Methods Fifty-six Japanese long-ear white rabbits of both sexes weighing 1.8-2.2 kg were randomly divided into four groups： Ⅰ normal control group was subjected to no I/R （C, n = 8）; ⅡI/R group （n = 16）; Ⅲ pinacidil preconditioning group （P, n = 16） and Ⅳ glibenclamide ＋ pinacidil preconditioning group （G, n = 16）. The animals were given heparin 300 IU/kg iv before being killed by a blow on the head. The hearts were immediately removed and momated in a Langendorff apparatus and perfused with 37℃ oxygenated Krebs-Hensleit （K-H） solution. Ischemia was induced by perfusion with 4℃ St Thomas cardioplegic solution in group I/R, P and G and maintained for 40 min followed by reperfusion with 37℃ oxygenated K-H solution. In group P received perfusion with 37℃ oxygenated 10μmol/L pinacidil for 30 min and group G received perfusion with 37℃ oxygenated 10 gmol/L glibenclamide for 10 min and then 37℃ oxygenated 10 μmol/L pinacidil for 30 min before I/R. Eight hearts were retrieved in group C after 10 min perfusion with 37℃ oxygenated K-H solution and at 60 and 120 min of reperfusion in group Ⅱ-Ⅳfor determinatiort of MDA and complement 3a （C3a） level and ICAM-1 expression in myocardium and the ratio of cardiomyocytes with NF-κBp65 positive nucleus. Coronary sinus effluent was collected at 10 min post-preparation equilibration （baseline） and 30 and 60 min of reperfusion for determination of CK activity and TNF-α concentration respectively. Results The CK activity and TNF-α concentration in coronary sinus effluent and the MDA and C3a level, and ICAM-1 expression in myocardium and the ratio of cardiomyocytes with NF-κBp65 positive nucleus were significantly lower in group P than in other 3 groups. Conchtsion Pinacidil preconditioning can protect myocardium against inflammatory response induced by I/R by opening ATP-sensitive K^＋ channel which can be blocked by glibenclamide.