红景天苷对兔急性心肌缺血早期心肌细胞凋亡的影响

Effect of salidroside on cardiomyocyte apoptosis during early acute myocardial ischemia in rabbits

目的观察红景天苷(Sal)对兔急性心肌缺血早期心肌细胞凋亡的作用,探讨其可能的作用机制。方法新西兰白兔36只,随机分为生理盐水(NS)组和Sal组,分别以NS及Sal(200 mg.kg-1.d-1)连续灌胃4周,结扎左冠状动脉前降支造成急性心肌缺血模型。各组分别于术后0、4.5、6 h取左室心肌制备石蜡切片,TUNEL染色计数凋亡细胞;摘取心脏标本前采血检测血肌酸激酶同工酶MB(CK-MB)、肌钙蛋白I(cTnI)、一氧化氮(NO)、一氧化氮合酶(NOS)含量。结果①2组缺血4.5、6 h血CK-MB、cTnI含量均较0 h显著升高(P<0.05),且Sal组较NS组低,但无统计学意义(P>0.05)。②2组急性心肌缺血早期不同时点(4.5 h及6 h)均可检出凋亡细胞,缺血4.5 h凋亡细胞指数高于缺血6 h,但无统计学意义(P<0.05);Sal组凋亡细胞指数较NS组明显减少(P<0.05)。③同一时点2组血NO、NOS含量比较,Sal组高于NS组(P<0.05);但同组内各时点NO、NOS含量比较,差异无统计学意义(P>0.05)。结论急性心肌缺血可诱导心肌细胞凋亡,Sal显著减少细胞凋亡并增加血NO含量,提示其抗凋亡作用可能与血NO含量增高有关。

AIM To investigate the effect of salidroside （Sal） on cardiomyocyte apoptosis during early acute myocardial ischemia and the possible action mechanism. METHODS Thirty-six white rabbits were randomly divided into normal saline （NS） group and Sal group. NS and Sal（200 mg·kg^-1·d^-1） were administrated for 4 weeks. Acute myocardial ischemia model was generated by the ligation of left anterior descending coronary artery. The rabbits were sacrificed at various time （0 h, 4.5 h and 6 h after coronary ligation）. The paraffin sections of left ventricular were analyzed to identify apoptotic myocytes by means of TUNEL （ terminal deoxynucleotidyl transferase dUTP nick end labeling） assay. The blood was extracted to detect the levels of creatine kinase-MB （CK-MB）, cardiac troponin I （cTnI）, nitric oxide （NO） and nitric oxide synthase （NOS） before the heart was excised. RESULTS （1）The blood CK-MB and cTnI increased significantly at 4.5 h and 6 h after ligation in both groups （P 〈 0.05）. However, no significant differences were found between Sal and NS groups （ P 〉 0.05）. （2）Apoptotic cells were detected at various time （4.5 h and 6 h） during early acute myocardial ischemia . Apoptotic cells decreased significantly in Sal group as compared with that in NS group （ P 〈 0.05） ; but there were no significant differences between different time （4.5 h and 6 h） in beth groups （ P 〈 0.05）. （3）The concentrations of blood NO and NOS in Sal group were significantly higher than those in NS group（P 〈 0.05）, however, no significant differences were found between various time in both groups（ P 〈 0.05）. CONCLUSION Acute myocardial ischemia could induce cardiomyocyte apoptosis. Salidroside might reduce apoptotic cells and increase the contents of blood NO in rabbits with acute myocardial ischemia. The results suggests that the anti-apoptesis effect of salidroside might be due to the increase of blood NO by salidroside treatment in rabbits with acute myocardial ischemia.