The effects of exercise on the renin-angiotensin system in blood and skeletal muscle after heart failure / 中华物理医学与康复杂志

ABSTRACT

Objective:To observe the effect of exercise on the renin-angiotensin system (RAS) in the blood and skeletal muscles of rats with chronic heart failure (CHF).Methods:Fifty male Wistar rats were randomly divided into a sedentary control group, an exercise control group, a model sedentary group and a model exercise group. CHF was modelled in the rats of the model sedentary and exercise groups, while those of the sedentary and exercise control groups received a sham operation. The exercise groups performed treadmill exercise for 8 weeks (5 times per week). After the 8 weeks the activity of angiotensin-converting enzyme (ACE) and ACE2 in the plasma and soleus muscle was determined using the fluorescent substrate method. Angiotensin II (AngII) and Ang (1-7) were detected in plasma and the soleus muscle using liquid chromatography. The expression of Ang II type 1 receptor (AT1R) and Mas receptor (MasR) in skeletal muscles was detected using western blotting.Results:Compared with the sedentary control group, there was significantly increased average ACE activity and lower average ACE2 activity in the model sedentary group. There was a significant decrease in the average plasma Ang II content and ACE activity, and a significant increase in the Ang-(1-7)/Ang II ratio in the model exercise group. Compared with the model sedentary group, the average ACE activity and plasma Ang II content was significantly lower in the model exercise group but the average ACE2 activity was significantly higher. Compared with the sedentary control group, the average Ang II content and AT1R protein expression in the soleus muscles had increased significantly in the model sedentary group, and the average expression of MasR protein in the soleus muscles increased significantly in the model exercise group. However, compared with the model sedentary group, the average content of Ang II and the average expression of AT1R protein in the soleus muscles had decreased significantly in the model exercise group and the average Ang-(1-7)/Ang II ratio had increased significantly.Conclusion:Exercise can induce the conversion of RAS from ACE-Ang II-AT1R to ACE2-Ang-(1-7)-MasR after chronic heart failure, at least in rats. The changes in the components of the RAS in the plasma and skeletal muscle differ.