Effect of high- intensity interval training on tissue changes of collagen type 1 and fibrosis percent in male rats with myocardial infarction

Myocardial infarction (MI) is defined pathologically as cardiac muscle cell death due to abnormal blood flow, prolonged coronary artery ischemia, and replacement of cardiac tissue necrosis as a dense fibrotic lesion. Expression of collagen-1 protein levels and fibrosis increase after myocardial infarction in cardiac tissue. The aim of present study was to investigate the effect of high- intensity interval training in tissue levels of collagen-1 and fibrosis in male rats with MI.

Thirty male Wistar rats (weight: 270±25gr) were randomly divided into three groups (n =10 each): Healthy control (sham), MI (control), and MI (trained). Correspondingly, in order to induce MI, the rats underwent left-anterior descending-coronary-artery coronary artery bypass grafting and then MI was confirmed by echocardiography. The rats performed the exercise protocols for 8 weeks and 5 sessions per week. At the end of intervention, the rats were sacrificed and the data were analyzed (P≤0.05).

The expression of levels of collagen-1 and fibrosis in cardiac tissue of rats with MI was significantly lower than control group (P≤0.001).

It seems that high- intensity interval exercises can prevent the negative effects of scar and fibrosis by attenuating the expression of tissue levels of collagen-1 and fibrosis in the cardiac tissue of rats with myocardial infarction, which is an important mechanism for cardiac function and prevention of heart damage.