鼠李黄素对心肌缺血再灌注大鼠心脏功能和免疫反应的调节作用

Regulatory Effect of Rhamnetin on Cardiac Function and Immune Response in Rats with Ischemia-reperfusion

目的研究鼠李黄素对大鼠心肌缺血再灌注损伤的作用及其机制。方法将100只SD大鼠随机分成正常组,模型组,鼠李黄素低(50 mg·kg^-1)、中(100 mg·kg^-1)、高(200 mg·kg^-1)剂量组,每组20只。除正常组外,各组大鼠采用结扎左冠状动脉前降支法制备心肌缺血模型。鼠李黄素各组按相应剂量灌胃,每天1次,连续20 d。BL-420信号采集系统检测大鼠MAP、HR和LVSP水平;ELISA检测血清中CK-MB、Mb、cTn I、IL-6、IL-1β、iNOS和TNF-α的表达;Western blotting检测心肌细胞中Bcl-2、Bax、caspase-3、caspase-9、TLR4、P-NF-κB p65和MIP-2;试剂盒检测心肌细胞中MDA和SOD含量;免疫组化检测心肌细胞中Ki67的表达;HE染色观察心肌损伤。结果与模型组比较,给药组MAP、HR和LVSP显著升高,CK-MB、Mb和cTn I表达显著降低,Bax表达显著下调,Bcl-2表达显著上调,SOD含量显著增高,MDA含量显著降低,Ki67阳性比率显著降低,心肌细胞恢复正常形态,caspase-3和caspase-9表达显著下调,IL-6、IL-1β、iNOS、TNF-α含量显著降低,TLR4、P-NF-κB p65和MIP-2表达显著降低。结论鼠李黄素主要是通过降低氧化应激水平,诱导细胞增殖,抑制细胞凋亡、减缓炎症反应等途径来保护心肌细胞,减缓缺血再灌注损伤危害。

OBJECTIVE To study the effect and mechanism of rhamnetin on myocardial ischemia-reperfusion injury in rats.METHODS One hundred SD rats were randomly divided into normal group,model group,rhamnetin low(50 mg·kg^-1),medium(100 mg·kg^-1)and high(200 mg·kg^-1)dose group,20 rats in each group.Except for the normal group,rats in each group were prepared by ligation of the left anterior descending coronary artery.Each group of rhamnoflavin was intragastrically administered at the corresponding dose once a day for 20 consecutive days.The MAP,HR,and LVSP levels in rats were detected by the BL-420 signal acquisition system.The expression of CK-MB,Mb,cTn I,IL-6,IL-1β,iNOS and TNF-αin serum was detected by ELISA.The expression of Bcl-2,Bax,caspase-3,caspase-9,TLR4,P-NF-κB p65 and MIP-2 in cardiomyocytes was detected by Western blotting.The content of MDA and SOD in cardiomyocytes was detected by kits.The expression of Ki67 in cardiomyocytes was detected by immunohistochemistry,and myocardial damage was observed by HE staining.RESULTS Compared with model group,in the administration group,MAP,HR,and LVSP were significantly increased,CK-MB,Mb,and cTn I expressions were significantly reduced,Bax expression was significantly down-regulated,Bcl-2 expression was significantly up-regulated,SOD content was significantly increased,MDA content was significantly reduced,and Ki67-positive ratio was significantly decreased,myocardial cells returned to normal morphology,caspase-3 and caspase-9 expressions were significantly down-regulated,IL-6,IL-1β,iNOS,TNF-αlevels were significantly reduced,and TLR4,P-NF-κB p65 and MIP-2 expressions were significantly reduced.CONCLUSION Rhamnetin mainly protects myocardial cells from myocardial ischemia-reperfusion by reducing oxidative stress,inducing cell proliferation,inhibiting apoptosis and slowing down inflammatory response.