1,6-二磷酸果糖预处理对离体大鼠心肌缺血再灌注损伤的影响

Fructose 1, 6-diphosphate with preconditioning on the effects of ischemia/reperfusion injury in isolated rat hearts

目的 探讨1,6-二磷酸果糖（FDP）预处理对大鼠离体心肌缺血再灌注损伤的保护作用.方法 应用Langendorff 离体心脏灌注系统制备离体大鼠心脏全心缺血再灌注模型.雄性SD 大鼠16 只,随机分为2 组,每组8 只缺血再灌注组（I/R 组）和1,6-二磷酸果糖预处理组（FPC组）,所有心脏予以缺血30 min,再灌注60 min.FPC 组在持续缺血前用含FDP 的K-H 液灌注15 min做预处理.记录各组心脏在平衡30 min（T0）、缺血30 min（T1）、再灌注5 min（T2）、再灌注15 min（T3）、再灌注30 min（T4）、再灌注60 min（T5）时的左心室发展压（LVDP）和左心室压力最大上升速率（＋dp/dtmax）、左心室舒张末压（LVEDP）和左心室压力最大下降速率（-dp/dtmax）、左心室收缩压（LVSP）、左心室舒张压（LVDP）、心率（HR）、冠状动脉流量（CF）,并计算（LVSP-LVDP）3心率.实验结束后取心肌组织用比色法测定其中的超氧化物歧化酶（SOD）和丙二醛（MDA）的含量;常规石蜡固定切片,以免疫组化法测定Bcl-2 和Bax 的表达及以TUNEL 法检测凋亡指数.结果 与I/R 组相比,FPC 组的LVDP、（LVSP-LVDP）3HR、CF 在T3～5 时点、＋dp/dtmax 在T2～5时点、HR 在T4～5 时点升高显著（P〈0.05,P〈0.01）,而LVEDP 在T2～5 时点降低显著（P〈0.05,P〈0.01）,表明FPC 组的心功能显著优于I/R 组,且FPC 组心肌中的SOD 增加而MDA 减少、Bcl-2升高而Bax 降低、心肌凋亡指数也显著下降.结论 FDP 预处理可明显改善大鼠离体缺血再灌注的心功能和减少氧自由基的生成及其对质膜的脂质过氧化作用而保护心肌.

Objective To study the cardioprotection of fructose 1, 6-diphosphate with preconditioning on ischemia/reperfusion injury in isolated rat hearts. Methods Made isolated rat heart global ischemia/reperfusion model with Lengendorff isolated heart perfusion system. Sixteen Sprague-Dawley rats were randomly divided into two groups(8 each): ischemia/reperfusion group(I/R group), fructose 1, 6-diphosphate preconditioning group(FPC group). All hearts experienced 30 min index ischemia followed by 60 min reperfusion. K-H liquid with fructose 1, 6-diphosphate was perfused for 15 min before index ischemia in FPC group. Left ventricular developed pressure(LVDP), maximal rate of left ventricular pressure of development(+dp/dtmax), left ventricular end-diastolic pressure(LVEDP), maximal rate of left ventricular pressure of decline(-dp/dtmax), left ventricular systolic pressure(LVSP), left ventricular diastolic pressure(LVDP), heart rate(HR) and coronary flow(CF), were recorded at 30 min of equilibration(T0), 30 min of ischemia(T1), and 5 min(T2), 15 min(T3), 30 min(T4), 60 min(T5) of reperfusion, and(LVSP-LVDP)×HR were calculated at each time point. At the end of the experiment, superoxide dismutase(SOD) and malondialdehyde(MDA) in myocardium tissue were detected by colorimetry. Myocardial fixed paraffin-embedded tissue sections were used to detect Bcl-2 and Bax by immunohistochemical method and measure apoptosis index by TUNEL. Results Compared with group I/R, LVDP,(LVSP-LVDP) ×HR and CF at T3-5, +dp/dtmax at T2-5, HR at T4-5, in group FPC elevated significantly(P<0.05 or P<0.01). While LVEDP in group FPC descended significantly at T2-5(P<0.05 or P<0.01), proved the cardiac function in group FPC were better at each time point. And SOD increased while MDA decreased, the expression of Bcl-2 augmented while the expression of Bax lessened, AI reduced significantly. Conclusion Preconditioning with fructose 1, 6-diphosphate can evidently improve isolated cardiac function in rats suffered ischemia/reperfusion, and can protect myocardial by reducing the production of oxygen free radicals and its function of lipid-peroxides to plasmalemma.