【摘要】 目的:观察沉寂信息调节因子2激活剂-白藜芦醇干预对大鼠缺血再灌注心肌细胞凋亡及沉寂信息调节因子2表达的影响。方法:实验于2005-03/10在汕头大学医学院细胞衰老实验室完成。选用雄性SD大鼠30只,按随机数字表法分为3组,即假手术组、缺血再灌注组和白藜芦醇组,每组10只。白藜芦醇组和缺血再灌注组大鼠结扎冠状动脉左前降支制备心肌缺血再灌注模型,30min后松开扎线,再灌注2h。假手术组只穿线不结扎。假手术组及缺血再灌注组给予二甲基亚砜-质量浓度为0.009的生理盐水1mL/kg,白藜芦醇组给予白藜芦醇10mg/kg,分别于缺血前15min及再灌注前1min以1mL/kg舌下静脉给药。实验结束取出心脏,应用免疫组织化学方法检测沉寂信息调节因子2同源物SIRT1及半胱氨酸蛋白酶3蛋白的表达。以背景灰度值进行标准校正,计算半胱氨酸蛋白酶3表达的相对量,其灰度值愈大则阳性强度愈大。采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法检测心肌细胞凋亡情况,凋亡指数=穴视野内凋亡细胞个数/视野内所有心肌细胞个数雪×100%。结果:30只大鼠全部进入结果分析,每组10只,无脱失。①白藜芦醇组大鼠心肌细胞的SIRT1阳性细胞率显著高于缺血再灌注组(P=0.008),但低于假手术组(P=0.040)。②白藜芦醇组大鼠心肌细胞的凋亡指数显著低于缺血再灌注组(P=0.000),而缺血再灌注组则显著高于假手术组(P=0.000)。③白藜芦醇组灰度值为27.40±1.87;而缺血再灌注组灰度值为34.69±1.71,着色强度显著高于白藜芦醇组(t=9.098,P=0.000)。结论:白藜芦醇可抑制缺血再灌注后心肌细胞凋亡,可能是通过增加沉寂信息调节因子2表达,抑制半胱氨酸蛋白酶3活性而发挥作用。更多还原

【Abstract】 AIM:To observe the effect of resveratrol,reactivator of silent information regulator 2 (SIR2),on myocardial cell apoptosis induced by ischemia and reperfusion in rats and SIR2 expression. METHODS: The experiment was performed at the Laboratory of Cell Senescence,Medical College,Shantou University between March and October 2005. A total of 30 male SD rats were divided randomly into sham operation group,ischemia-reperfusion group and resveratrol group with 10 rats in each group. The left anterior descending branch of coronary artery was occluded for 30 minutes followed by a 2-hour reperfusion in rats of the resveratrol group and ischemia-reperfusion group to establish myocardial ischemia-reperfusion models. The rats in the sham operation group were only threaded without deligation. The rats in the sham operation group and ischemia-reperfusion group were administered dimethyl sulphoxide-0.009 saline 1 mL/kg,while those in the resveratrol group received 10 mg/kg resveratrol. Administration was performed before the onset of ischemia for 15 minutes and before the onset of reperfusion for 1 minute as 1 mL/kg by vena sublingualis. Immunohistochemical method was used to observe expression of SIRT1 and caspase-3 protein,congener of SIR2. Criteria were corrected with gray scale. Relative amount of caspase-3 was calculated. The higher the gray scale,the higher the positive intensity was. The apoptosis of myocardial cells was assessed by dUTP nick end-labeling mediated by terminal deoxynucleotidyl transferase (TdT). Apoptotic index referred to (number of apoptotic cells in visual field/number of all the myocardial cells in visual field) ×100%. RESULTS: Totally 30 rats were involved in the result analysis (10 rats in each group) without dropout. ①The SIRT1 positive cell rate of myocardial cells of rats in the resveratrol group was significantly higher than that in the ischemia-reperfusion group (P=0.008),but lower than that in the sham operation group (P=0.040). ②The apoptotic index of the resveratrol group was obviously lower than that in the ischemia-reperfusion group (P=0.000),while it was markedly higher in the ischemia-reperfusion group than that in the sham operation group (P=0.000). ③The gray scale in the resveratrol group was (27.40±1.87),while it was (34.69±1.71) in the ischemia-reperfusion group. The coloring intensity was remarkably higher than that in the resveratrol group (t=9.098,P=0.000). CONCLUSION: The resveratrol can inhibit the apoptosis of myocardial cells after ischemia and reperfusion,which may play a role by increasing the expression of SIR2 and preventing the activity of caspaes-3.更多还原