目的:在心脏缺血期间,心肌细胞中氧气的缺乏通过打开线粒体通透性过渡孔(mPTP)引起pH和离子干扰以及细胞死亡。考虑到线粒体ATP依赖性钾通道(mt-KATP)对这些孔的抑制作用和molin的抗缺血作用,我们假设它可能通过激活mt-KATP及其抗氧化作用发挥积极作用。
方法:用富含莫林(0.25、0.5和1mg/L)或5-羟基癸酸酯(5-HD,mt-KATP阻滞剂;100μM)或根据需要在开始局部缺血前5分钟至再灌注期的前10分钟。分别用Krebs-Henseleit溶液60或120分钟进行再灌注,以进行生化评估(乳酸脱氢酶和丙二醛水平)或评估心肌梗塞面积。在实验过程中,记录血液动力学功能并确定心律失常.
结果:我们的研究结果表明,morin可减少梗死面积。此外,smoin灌注可以显著防止缺血期间丙二醛的过量产生。总室性异位搏动与丙二醛水平具有相同的显著变化,在缺血和再灌注阶段。Morin还可以相对改善缺血引起的血流动力学功能障碍。所有提到的sorin的保护作用被伴随的5-HD灌注逆转。
结论:Morin通过抗氧化作用对缺血性心脏具有保护作用。这也表明莫林和mt-KATP的心脏保护作用之间存在联系。然而,需要更多的研究来证明这一初步假设。
OBJECTIVE: During heart ischemia, the lack of oxygen in the myocardial cells causes pH and ion disturbances and cell death through opening mitochondrial permeability transition pores (mPTP). Considering the inhibitory effects of mitochondrial ATP-dependent potassium channels (mt-KATP) on these pores and anti-ischemic effects of morin, we hypothesized that it may exert its positive effects via activating mt-KATP as well as its anti-oxidative effects.
METHODS: Isolated rat hearts were perfused by Krebs-Henseleit solution enriched with the morin (0.25, 0.5 and 1 mg/L) or 5-hydroxydecanoate (5-HD, a mt-KATP blocker;100 μM) or both as needed 5 min before starting regional ischemia till the first 10 min of the reperfusion period. The reperfusion was developed with Krebs-Henseleit solution 60 or 120 min respectively for biochemical evaluations (lactate dehydrogenase and malondialdehyde level) or the assessment of myocardial infarct size. During the experiments, hemodynamic functions were recorded and cardiac arrhythmias were determined.
RESULTS: Our findings demonstrated that morin reduced the infarct size. Also, morin perfusion could remarkably prevent the malondialdehyde over-production during ischemia. Total ventricular ectopic beats had the same significant changes as the malondialdehyde level, in both ischemia and reperfusion phases. Morin could also relatively improve the ischemia-induced hemodynamic dysfunction. All mentioned protective effects of morin were reversed by concomitant perfusion of 5-HD.
CONCLUSIONS: Morin has protective effects against ischemic hearts through anti-oxidative effects. It also suggests a link between the cardioprotective effects of morin and mt-KATP. However, additional studies are required to prove this preliminary hypothesis.