虾青素对Beagle犬心肌梗死模型的保护作用及其降低氧化应激机制

Protective effect of astaxanthin on experimental myocardial infarct in Beagle dogs and its mechanism on lowing oxidative stress

目的:探讨虾青素(ASX)对心肌梗死Beagle犬的保护作用及其降低氧化应激机制。方法:Beagle犬给予虾青素(100 mg·kg^(-1)·d^(-1),虾青素组)或空白溶媒(空白组和心肌梗死组)1周后,结扎犬冠状动脉左前降支制备心肌梗死模型,随后再连续给药3周。测定手术不同时期的心电图和血清心肌酶谱和抗氧化酶系的变化,取心肌梗死边缘组织进行蛋白免疫印迹实验测定核因子相关因子2(Nrf2)的表达,取心脏组织进行病理学观察。结果:虾青素明显降低心肌梗死犬心电图的ST段抬高,降低血清肌酸激酶同工酶(CKMB)和肌钙蛋白I(c Tn I)和丙二醛(MDA)水平,升高超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力,上调心肌组织的Nrf2蛋白的表达,减少心肌梗死面积,降低心肌细胞坏死程度。结论:虾青素对心肌梗死犬具有保护作用,其机制与降低氧化应激有关。

AIM：To investigate the protective effect of astaxanthin （ASX） on Beagle dogs after myocardial infarction （MI） and its mechanism on lowing oxidative stress.METHODS：The Beagle dogs were dosed with astaxanthin [the ASX group,100 （mg·kg-1·d-1） or distilled water （the sham-operated group and the MI group） for one week,The MI model was made by ligation of the left coronary artery,and continue to give ASX for three weeks.Electrocardiogram （ECG） and myocardial enzyme spectrum and antioxidant in serum were measured at different time during surgery.Western blot was used to examine the expression of nuclear factor erythroid 2-related factor-2 （Nrf2）at the infarcted border zone,and the pathomorphological changes of heart were observed.RESULTS：With ASX,the elevation of ECG ST segment in myocardial infarction dogs was significantly decreased,the serum level of the creatine kinase-MB （CK-MB） and troponin Ⅰ （cTnI） and malondialdehyde （MDA） was also reduced,while the activity of superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） upregulated,the protein expression of Nrf2 at the infarcted border zone were increased.Also,the area of MI and the degree of myocardial cell necrosis in dogs were reduced.CONCLUSION：Astaxanthin plays a protective role in MI dogs,its mechanism is related to reduce oxidative stress.