Alteration of skeletal and cardiac muscles function in mice background: a focus on high intensity interval training.

Duchenne muscular dystrophy (DMD) is a recessive hereditary myopathy due to deficiency of functional dystrophin. Current therapeutic interventions need more investigation to slow down the progression of skeletal and cardiac muscle weakness. In humans, there is a lack of an adapted training program. In animals, the murine model with a background (D2-) was recently suggested to present pathological features closer to that of humans. In this study, we characterized skeletal and cardiac muscle functions in males and females D2- mice compared to control groups. We also evaluated the impact of high intensity interval training (HIIT) in these muscles in females and males. HIIT was performed 5 times per week during a month on a motorized treadmill. Specific maximal isometric force production and weakness were measured in the muscle (TA). Sedentary male and female D2- mice produced lower absolute and specific maximal force compared to control mice. Dystrophic mice showed a decline of force generation during repetitive stimulation compared to controls. This reduction was greater for male D2- mice than females. Furthermore, trained D2- males showed an improvement in force generation after the fifth lengthening contraction compared to sedentary D2- males. Moreover, echocardiography measures revealed a decrease in left ventricular end-diastolic volume, left ventricular ejection volume and left ventricular end-diastolic diameter in sedentary male and female D2- mice. Overall, our results showed a serious muscle function alteration in female and male D2- mice compared to controls. HIIT may delay force loss especially in male D2- mice.