丹酚酸B调控Piezo1通道保护心肌梗死后心力衰竭大鼠血管舒缩功能

Protection of vasodilatory function in rats with post-infarction heart failure by salvianolic acid B via modulating Piezol channel

基于机械敏感性离子通道Piezo1探讨丹酚酸B调节心肌梗死后心力衰竭大鼠血管舒缩功能。采用冠状动脉左前降支结扎法制备大鼠心肌梗死后心力衰竭模型。造模成功后,将大鼠随机分为模型组、丹酚酸B组(0.5 g·kg^(-1)),另设假手术组,灌胃14 d,每天1次。实验结束时,超声心动图检测大鼠左室射血分数(LVEF)、左心室短轴缩短率(LVFS)、每搏输出量(SV)、心输出量(CO)等心功能指标;生化分析法检测血清肌酸激酶(CK)、肌酸激酶MB同工酶(CK-MB)、乳酸脱氢酶(LDH)活性;酶联免疫吸附测定(ELISA)法检测血清心房钠尿肽(ANP)、脑利钠肽(BNP)、血管紧张素Ⅱ(AngⅡ)含量;2,3,5-三苯基氯化四氮唑(TTC)染色法观察心肌梗死面积;取胸主动脉进行离体血管环实验,测定各组内皮依赖性舒张作用(EDD)及非内皮依赖性舒张作用(EID),检测Piezo1通道激动剂(Yoda1)及抑制剂(Dooku1)对EDD及EID的影响;Masson染色观察胸主动脉结构变化;免疫荧光染色检测大鼠胸主动脉Piezo1及CD31蛋白表达;Western blot检测血管Piezo1表达水平。结果显示,与模型组相比,丹酚酸B组LVEF、LVFS、CO、SV等明显升高,心肌梗死面积减低,血清CK、CK-MB、LDH活性降低,ANP、BNP、AngⅡ含量下调;改善胸主动脉EDD及EID,增加心肌梗死后心力衰竭大鼠血管内皮细胞Piezo1表达进而增加Yoda1对EDD的反应性,上调血管平滑肌细胞Piezo1表达,增加Dooku1对EID的反应性。综上,丹酚酸B能够改善心肌梗死后心力衰竭大鼠心功能、保护心肌梗死后心力衰竭大鼠血管舒缩功能,其作用可能与Piezo1在血管内皮细胞及平滑肌细胞的表达有关。

To explore the regulation of vasodilatory function in rats with post-infarction heart failure by salvianolic acid B(Sal-B)based on the mechanosensitive ion channel,namely Piezo1.A post-infarction heart failure model of rats was prepared by ligation of the left anterior descending coronary artery.After successful modeling,the rats were randomly divided into the model group,Sal-B group(0.5 g·kg^(-1)),and sham-operated group,and they were gavaged for 14 days,once a day.At the end of the experiment,echocardio-graphy was used to detect cardiac function indexes such as LVEF,LVFS,SV,and CO in rats;biochemical analysis was used to detect serum CK,CK-MB,and LHD activities;ELISA was used to detect serum ANP,BNP,and AngⅡcontents;TTC staining was used to observe the myocardial infarction area,and the thoracic aorta was taken to perform an ex vivo vascular ring test,so as to determine en-dothelium-dependent dilation(EDD)and endothelium-independent dilation(EID)of different groups.The effects of Piezo1 channel agonist(Yoda1)and inhibitor(Dooku1)on EDD and EID were detected;Masson staining was performed to observe the structural changes of the thoracic aorta;immunofluorescence staining was performed to detect the protein expression of Piezo1 and CD31 in the thora-cic aorta of the rats,and Western blot was performed to detect the expression level of Piezo1 in the vessel.The results showed that compared with those of the model group,the LVEF,LVFS,CO,and SV of the Sal-B group were significantly increased,and the myocardial infarction area was reduced.The activities of serum CK,CK-MB,and LDH were decreased,and the levels of ANP,BNP,and AngⅡwere down-regulated.The EDD and EID of the thoracic aorta were improved,and the expression of Piezo1 in the vascular endothelial cells of the rats with post-infarction heart failure was increased to enhance the responsiveness of Yoda1 to EDD,and the Pi-ezo1 expression in vascular smooth muscle cells was up-regulated to increase the responsiveness of Dooku1 to EID.In conclusion,Sal-B can improve cardiac function and protect vasodilatory function in rats with post-infarction heart failure,and its effect may be related to the expression of Piezo1 in vascular endothelial cells and smooth muscle cells.