Mechanism of TEAS at PC6 in Protecting Myocardial Injury in Rats with Simulated Microgravity Based on AMPK/PFK-2 Signaling Pathway
Objective:To observe the impacts of transcutaneous electrical acupoint stimulation(TEAS)on protein and mRNA expressions of cardiac function,myocardial pathological morphology,myocardial energy metabolism and glycolytic related factors adenylate activated protein kinase α1(AMPKα1)and 6-phosphofructo-2-kinase(PFK-2)in rats with simulated microgravity,thus to explore the protective effect and mechanism of TEAS on myocardium injury induced by simulated microgravity.Methods:A total of 36 SPF Wistar rats were randomly divided into the blank group,the model group,and the TEAS group,with 12 rats in each group.The simulated microgravity model was prepared by tail suspension method for 30 days.On the second day after modeling,the TEAS group was interfered with electro-needling bilateral Neiguan(PC6),density wave,frequency of 2 Hz/100 Hz,intensity of 1 mA,once every other day,30 min each time,a total of 14 times.Changes in body weight were recorded weekly;mass of heart and right soleus muscle and tibia length were measured after 4 weeks of treatment.Echocardiography was used to detect heart function,HE staining was used to observe the pathological changes of myocardial tissues,Colorimetry and chemiluminescence were used to detect the contents of ATP and AMP in myocardial tissues,and Western blot and Real-Time PCR were used to detect the protein and mRNA expressions of AMPKα1 and PFK-2.Results:Compared with those in the blank group,the body weight,wet weight of soleus muscle,and its ratio to body weight,the left ventricular mass,the ratio of heart mass to tibial length were significantly reduced in the model group(P＜0.01);the cardiac function declined,and the myocardial fibers arranged sparsely,fractured,and dissolved in the model group;the content of ATP in myocardial tissues significantly decreased(P＜0.01),the content of AMP significantly increased(P＜0.05),and the protein and mRNA expressions of AMPKα1 and PFK-2 significantly decreased in the model group(P＜0.01).Compared with those in the model group,the body weight,the left ventricular mass and the ratio of heart mass to tibial length significantly increased(P＜0.05),the cardiac function improved,the myocardial fibers arranged neatly,and there was no obvious necrosis or dissolution in the TEAS group;the content of ATP significantly increased and the content of AMP significantly decreased(P＜0.05),and the protein and mRNA expressions of AMPKα1 and PFK-2 significantly increased in the TEAS group(P＜0.01,P＜0.05).Conclusion:TEAS at PC6 can ameliorate cardiac function and structure damage and increase the level of cardiac energy metabolism in rats with simulated microgravity.The mechanism may be related to up-regulating the expressions of AMPKαl and PFK-2 in myocardial tissues,thus to enhance the myocardial glycolysis process to protect the myocardial damage induced by simulated microgravity.
万方数据
