异丙酚对大鼠心肌缺血再灌注损伤中TLR-4、TNF-α和NF-κb表达及其超微结构的影响

Effects of propofol on the changes in myocardial Toll-like receptor 4 and TNF-α and NF-κb protein expressions and ultrastructure in ischemia-reperfusion injury in rats

目的探讨异丙酚对大鼠缺血再灌注心肌Toll样受体（TLR-4）、肿瘤坏死因子-α（TNF-α）和核转录因子（NF-kb）的影响。方法健康雄性SD大鼠30只，体质量250-320g，随机分为3组，每组10只。对照组（A组）左冠状动脉前降支穿线；缺血再灌注组（B组）左冠状动脉前降支穿线结扎30min后，再灌注120min；异丙酚组（c组）缺血前10rain经股静脉持续静脉注射异丙酚5mg／（kg·h），输注至再灌注结束。3组再灌注120rain后，通过透射电镜观察心肌细胞超微结构的改变，并测定心肌TLR-4、TNF-α及NF-kb蛋白的表达。结果透射电镜下观察超微结构显示，B组、c组较A组明显加重了心肌组织结构和线粒体的损害，c组损伤较轻。与A组比较，B、C组心肌TLR-4、TNF-α及NFKb蛋白表达上调，C组较B组心肌TLR-4、TNF-α及NF-kb蛋白表达下调。结论静脉注射异丙酚可保护心肌受损，并抑制大鼠缺血再灌注心肌TLR-4、TNF-α及NF-kb的表达。

Objective To investigate the effects of propofol on the changes in myocardial Toll-like receptor 4 （TLR-4） and TNF-α and NF-xb protein expressions in ischemia-reperfusion injury （I/R）. Methods Thirty healthy male SD rats weighing 250 - 320 g were randomly divided into 3 groups （n = 10 for each）： Group A, sham operation; Group B, I/R; and Group C, propofol ＋ I/R. In Groups B and C myocardial I/R was induced by occlusion of the left anterior descending artery （LAD） for 30 min, followed by 120 min reperfusion. In Group C propofol was given intravenously 10 min before myocardial ischemia, followed by continuous infusion of propofol at 5 mg/（kg · h） until the end of 120 rain reperfusion. In Groups A and B normal saline instead of propofol was given. The myocardial tissues were taken at the end of 120 rain; ultrastructural changes of myocardial cells were observed under X-ray electron microscope and the expressions of TLR-4 mRNA as well as TNF-α and NF-kb protein were determined. Results Ultrastructural observation under electron microscope showed significantly worsened damage in myocardial tissue structure and mitochondria in Groups B and C compared with Group A. The myocardial expressions of TLR-4 and TNF-α and NF-kb protein were significantly higher in Groups B and C than in control Group A. The myocardial expressions of TLR-4 and TNF-α and NF-kb protein were down-regulated in Group C compared with Group B. Oonclusiorl Intravenous injection of propofol can protect against myocardial damage.Propofol can suppress the increase in myocardial TLR-4 and TNF-α and NF-kb protein expressions induced by I/R.