异鼠李素对缺血再灌注损伤大鼠心室肌细胞凋亡的抑制作用

Inhibition apopotosis effect of Isorhamnetin on rat ventricular myocytes of ischemia reperfusion injury

目的:研究异鼠李素对缺血再灌注(I/R)损伤后心室肌细胞的生长与增殖的变化,拟探索异鼠李素对缺血再灌注损伤后心肌细胞的保护作用。方法:将新生SD大鼠心肌细胞随机分为三组,分别为:I/R-/Isor-,I/R+/Isor-和I/R+/Isor+组。通过MTT法测定异鼠李素的最适宜浓度,乳酸脱氢酶活性检测,流式细胞术检测细胞凋亡率,Western blot分析各组Bcl-2,Bax,p53及NF-κB/p65蛋白的表达情况。结果:通过MTT法测得异鼠李素的最佳浓度为4μM。缺血再灌注心室肌细胞即I/R+/Isor-组乳酸脱氢酶活力明显上升,而与其相比,异鼠李素处理组即I/R+/Isor+组的乳酸脱氢酶活力下降。流式细胞术分析结果显示由缺血再灌注引起的细胞凋亡率明显增加,而经异鼠李素处理后,凋亡率降低。Western blot检测结果显示同I/R+/Isor-组相比bcl-2的表达量升高,bax、p53和核内NF-κB/p65的表达量则下降。结论:异鼠李素对心肌缺血再灌注损伤具有一定的保护作用,并呈现一定的浓度效应,其保护机制为:通过抑制乳酸脱氢酶的活力来减轻缺血再灌注对心肌细胞的损伤抑制凋亡,也与NF-κB等信号途径有关。

Objective： To explore the effect of isorhamnetin on injury of ventricular myocytes induced by ischemic reperfusion （I/ R）. Methods：Ventricular myocytes were obtained from neonatal SD rats, and then were divided randomly into three groups, namely I/R^-/Isor^-, I/R^＋/Isor^-- and I/R^＋/Isor^＋ group. By MTT assay, we got the appropriate concentrations of Isorhamnetin and the following experiments were based on this concentration. Apoptosis induced by I/R treatment were measured by lactate dehydrogenase （LDH） activity and FCM. Expressions of bax, bcl-2, p53 and NF-κB/p65 were detected by Western blot. Results： According to MTT assay, the appropriate concentrations of Isorhamnetin to protect the ventricular myocytes from ischemic reperfusion injury was 4μM. I/R could significantly increase apoptosis in ventricular myocytes which was detecteded by MTT, lactate dehydrogenase （LDH） activity and FCM. But Isorhamnetin could decrease the apoptosis and promote the vitality of these cells. Corresponding to the reduced apoptosis rate in the I/R^＋/Isor^＋ group, Western blot assay showed increased amount of Bcl-2, decreased amount of Bax, p53 and nuclear accumulation of NF-kB/p65. Conclusion： Isorhamnetin seemed to ha＇,c the positive effect to protect rat ventricular myocytes from ischemia reperfusion injury. However, the positive or negative effects of Isorhamnetin on the viability of ventricular myocytes exhibited a dose dependent manner. Moreover, In order to suppress apoptosis, expressions of pro-apoptosis gene could be up-regula- ted while anti-apoptosis gene be down-regulated by Isorhamnetin to activate or block some signaling pathways.