Aerobic Exercise Improves Cardiac Function In Rats With Heart Failure By Regulating Norepinephrine Transporter

Objective: This study explored the possible mechanism of long-term aerobic exercise to suppress HF sympathetic hyperexcitability by observing the effect of 10-week aerobic exercise on the expression of norepinephrine transporter(NET)in rats with heart failure(HF).Methods: thirty six healthy male Wistar rats were randomly divided into sham operated group(sham group),HF sed group(HF sed group)and HF ex group(HF ex group).Coronary artery ligation was used to establish the heart failure rat model.The ejection fraction of HF sed group and HF ex group was lower than 45%.Incremental load exercise test was used to detect the difference The exercise ability of rats was measured.The rats in sham group and HF sed group kept quiet after operation.The rats in HF ex group performed regular aerobic exercise on the treadmill for 10 weeks.Echocardiography was used to determine the structure and function of the heart,including body weight(BW),heart weight(HW),heart rate(HR),shortening fraction(FS),left ventricular ejection fraction(LVEF),body mass index(HW / BW),left ventricular end systolic diameter(LVESD),left ventricular end diastolic diameter(LVEDd).High performance liquid chromatography was used to detect the myocardium and plasma noradrenalin The expression of cardiac net mRNA was detected by real-time fluorescence quantitative PCR,and the expression levels of cardiac net total protein,membrane protein and cytoplasmic protein were detected by Western blot.Results: after 10 weeks of aerobic treadmill exercise,BW,FS and LVEF decreased(P < 0.01)and HW,HW / BW,LVESD,LVEDd and HR increased(P < 0.05)in HF sed group compared with sham group,while LVEDd and LVEDd decreased(P < 0.05)and FS and LVEF increased(P < 0.05)in HF ex group compared with HF sed group,indicating that aerobic exercise can adjust the heart structure and function of rats to a certain extent and improve heart failure.Compared with sham group,NE in plasma and myocardium of HF sed group was higher and NE in myocardium was lower(P < 0.05);compared with HF sed group,NE in plasma and myocardium of HF ex group was lower and NE in myocardium was higher(P < 0.05).NE content in plasma and myocardium of HF ex group was close to that of HF sed group.Comparing the changes of NE in rats before and after exercise,we can know that aerobic exercise can regulate the expression of NE in plasma and myocardium of rats.Compared with sham group,net mRNA expression in sympathetic ganglia decreased in HF sed group(P < 0.05);compared with HF sed group,net mRNA expression in sympathetic ganglia increased in HF ex group(P < 0.05);compared with sham group,net protein expression in total net and membrane decreased(P < 0.05),net protein expression in cytoplasm increased(P < 0.05);compared with HF sed group,net protein expression in total net and membrane increased in HF ex group The results showed that long-term regular aerobic training could up regulate the expression of net transporter and net mRNA in HF rats.Conclusion: in this study,the model of heart failure rats was successfully made by coronary artery ligation.Through 10 weeks of aerobic exercise training,it was confirmed that long-term regular aerobic exercise can significantly improve the heart function of HF rats.It was found that exercise can increase the re intake of ne by up regulating the expression level of net,suggesting that exercise can effectively inhibit the apoptosis of myocardial cells and ventricular weight after heart failure It is suggested that exercise can regulate net expression to inhibit sympathetic hyperactivity.