Study On The Mechanism Of Zhigancao Decoction Against Arrhythmia Caused By Rat MIRI Based On PI3K/Akt/mTOR Signal Pathway

Objective To observe the effect of Zhigancao Decoction on myocardial ischemia-reperfusion injury(MIRI)-induced arrhythmia in rats,and to study the mechanism of autophagy gene,protein and autophagy in PI3K/Akt/mTOR pathway during MIRI The mechanism of action of soup on arrhythmia caused by MIRI injury.Methods 72 healthy male Sprague-Dawley rats were randomly divided into 6groups,12 in each group.That is,high-dose group of Zhigancao Decoction,middle dose group of Zhigancao Decoction,low dose group of Zhigancao Decoction,Wenxin Granule Group,model group and sham operation group.The dosages of the low,middle and high doses of Zhigancao Decoction were 11.43,22.86and45.72g/kg,respectively,and the dose of Wenxin Granules was 2.43g/kg.The sham operation group and the model group were given the same amount of distilled water,and each group was intragastrically administered at a volume of 10 ml/kg twice a day for 10 consecutive days.The MIRI model was prepared urgently 2hours after the last administration.Except for the sham operation group,only the thread was ligated and not ligated.The rats in other groups were surgically ligated to the left anterior descending coronary artery for 30 minutes,and then the reperfusion was performed for 60 minutes.The model was prepared after successful modeling.The blood and heart tissue of the rats in the group.Main observation: 1.Record the lectrocardiogram,calculate the duration and incidence of ventricular tachycardia,the duration and incidence of ventricular fibrillation in30 minutes after ischemia and 60 minutes after reperfusion.2.Detection of myocardial infarct size in rats by TTC-Evans method.3.Serum levels of creatine kinase(CK),lactate dehydrogenase(LDH)and aspartate aminotransferase(AST)and total antioxidant capacity(T-AOC)were measured by automatic biochemical analyzer.4.The content of cardiac troponin(CtnI)was detected by Elisa method.5.Immunohistochemistry was used to detect the expression of phosphatidylinositol3-kinase(PI3K),protein kinase B(Akt),and mammalian target of rapamycin(mTOR).6.Western-blot was used to detect autophagy-related protein microtubule-associated protein 1 light chain 3(LC-3),autophagy markers Beclin1 and PI3K/Akt/mTOR signaling pathway-related protein expression and phosphorylation of p-PI3 K,p-The level of Akt,p-mTOR.Results 1.The incidence of ventricular tachycardia in the model group was 100%,and the incidence of ventricular fibrillation was 91.67%.After pretreatment with Zhigancao Decoction,the duration of each drug-administered group was significantly shortened(P<0.01),and the ventricular tachycardia in the high-dose group.The incidence of ventricular fibrillation was significantly decreased(P<0.01)and the duration was the shortest(P<0.01).The results of TTC-Evans test showed that the myocardial infarct size of the model group was significantly increased compared with the sham operation group(P<0.05).Compared with the model group,the different doses of Zhigancao Decoction and Wenxin Granules the group could significantly reduce the myocardial infarct size of the rats(P<0.05),and the effect of the middle dose group of Zhigancao Decoction was more obvious.2.Compared with the sham operation group,the levels of CK,LDH and AST were significantly increased.P<0.01),compared with the model group,the levels of CK,LDH and AST in the high,middle and low dose groups of Zhigancao Decoction were significantly lower;compared with the sham operation group,the level of T-AOC in the model group was significantly lower(P< 0.05),compared with the model group,the T-AOC level was significantly increased in each dose group of Zhigancao Decoction.The Elisa method showed that the content of CtnI in the model group was significantly higher than that in the sham operation group(P<0.01),and the content in the high,middle and low dose groups of Zhigancao Decoction was significantly lower than that in the model group(all P<0.01).The results of immunohistochemistry showed that the expression of PI3 K,AKT andmTOR in the model group was significantly higher than that in the sham operation group(P<0.01).Compared with the model group,the group of Zhigancao administration group The expression of PI3 K,AKT and mTOR decreased significantly with increasing dose(P<0.01).The results of Western-blot showed:(1)the expression of autophagy-related proteins LC-3 and Beclin1: compared with the sham operation group,the expression level in the model group was significantly increased(P<0.01);The expression of each dose group decreased with increasing dose(P < 0.01).(2)Expression of PI3K/Akt/mTOR-related proteins in the signaling pathway: Compared with the sham operation group,the ratio of p-PI3K/PI3 K,p-Akt/Akt,and p-mTOR/mTOR in the model group was significantly lower(P-all<0.01);Compared with the model group,the ratio in the respective administration groups of Zhigancao soup was significantly increased.Conclusion 1.Pretreatment with Zhigancao Decoction can significantly reduce the occurrence of MIRI-induced arrhythmia.Pretreatment with Zhigancao Decoction can significantly reduce myocardial infarct size and decrease myocardial infarction in MIRI rats,indicating that Zhigancao Decoction has anti-MIRI-induced arrhythmia.Zhigancao Decoction can improve the antioxidant capacity of cardiomyocytes,inhibit excessive autophagy of cells,up-regulate the expression of PI3 K,and further up-regulate the expression of Akt and mTOR,possibly through anti-MIRI-induced arrhythmia through PI3K/Akt/mTOR signaling pathway.effect.