Downhill exercise training in monocrotaline-injected rats: Effects on echocardiographic and haemodynamic variables and survival.

Abstract

BACKGROUND: Eccentric exercise training has been shown to improve muscle force strength without excessive cardiovascular stress. Such an exercise modality deserves to be tested in pulmonary arterial hypertension. AIM: We aimed to assess the effects of an eccentric training modality on cardiac function and survival in an experimental monocrotaline-induced model of pulmonary arterial hypertension with right ventricular dysfunction. METHODS: Forty rats were randomly assigned to one of four groups: 40mg/kg monocrotaline-injected sedentary rats; 40mg/kg monocrotaline-injected eccentric-trained rats; sedentary control rats; or eccentric-trained control rats. Eccentric exercise training consisted of downhill running on a treadmill with a -15° slope for 30minutes, 5 days a week for 4 weeks. Training tolerance was assessed by echocardiography, right ventricle catheterization and the rats' maximal eccentric speed. RESULTS: Survival in monocrotaline-injected eccentric-trained rats was not different from that in monocrotaline-injected sedentary rats. Monocrotaline-injected eccentric-trained rats tolerated this training modality well, and haemodynamic status did not deteriorate further compared with monocrotaline-injected sedentary rats. The eccentric maximal speed decline was less pronounced in trained compared with sedentary pulmonary arterial hypertension rats. CONCLUSIONS: Eccentric exercise training had no detrimental effects on right heart pressure, cardiac function and survival in rats with stable monocrotaline-induced pulmonary hypertension.