缺血后处理对在体大鼠缺血-再灌注心肌细胞色素P450表氧化酶2J3／环氧二十碳三烯酸系统的影响

目的观察缺血后处理拈抗心肌缺血-再灌注损伤时内源性细胞色素P450表氧化酶2J3／环氧二十碳三烯酸（CYP2J3／EET）系统的变化。方法复制在体大鼠心肌缺血-再灌注损伤及缺血后处理模型。雄性Wistar大鼠（250—300）g随机分为三组：假手术组（Sham）、缺血-再灌注组（I—R）、缺血后处理组（IPo）。动脉插管测定心功能指标，采用TTC染色法测定心肌梗死范围，采用RT—PCR法检测心脏细胞色素P450表氧化酶亚型2J3（CYP2J3）mRNA表达，采用Western blot方法测定心肌组织CYP2J3蛋白水平的变化，高效液相色谱法测定11，12-EET含量。结果与I-R组相比IPo组左室收缩末压（LVESP）、左室内压最大上升／下降速率（±LVdp／dtmax）均显著升高；心肌梗死面积减少20．76％（P〈0．01）；与Sham组及I—R组相比IPo组CYP2J3mRNA、CYP2J3蛋白及11，12-EET含量明显升高（P〈0．05）。结论Po可减轻在体心肌I—R损伤同时上调心脏CYP2J3／EET系统；提示CYP2J3／EET系统可能与IPo拮抗心脏I-R损伤作用相关。

Effect of Ischemic Postconditioning on CYP2J3/EET System in Rat Heart in Vivo

Objective To observe the variation of endogenous CYP2J3/EET system in rat heart in vivo after ischemic postconditioning（ IPo）. Methods All Wistar rats were randomly divided into three groups as follows： Sham group, I/R group and IPo group. The myocardial ischemia-reperfusion and the IPo models in vivo were made. Observing the changes of heart rate （HR）, left ventricular end-systolic pressure（LVESP） and maximum velocity of increase or decrease of LV pressure（± LVdP/dtmax）. Infarction size was measured by triphenyhetrazolium chloride（TTC） staining. The expression of CYP2J3 mRNA was tested by RT-PCR. The expression of CYP2J3 protein was detected by Western blot. 11, 12-epoxyeicosatrienoic acid（ 11, 12-EET） was observed by high-performance liquid chromatography（ HPLC）. Results Compared with I/R group, the levels of LVESP and ± LVdp/dt were all significantly increased. Infarction size was significantly reduced in IPo group compared with I-R group （ P 〈 0.05）. CYP2J3 mRNA was increased compared with I/R and Sham groups, consistent with increased expression of CYP2J3 protein and 11, 12-EET. Conclusion These data suggest that IPo protects myocardium against I-R injury which may involve endogenous activation of CYP2J3/ EET system.