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Exercise Training Reduces Inflammation and Fibrosis and Preserves Myocardial Function and Perfusion in a Model of
Thayrine R Damasceno1, Denise M Tanaka2, Enrico F Magnani1
1Universidade Federal de Minas Gerais, Belo Horizonte, MG - Brasil.
Insights
Aerobic physical training (APT) improved heart function and reduced inflammation and fibrosis in a hamster model of Chronic Chagas cardiomyopathy (CCC). APT also prevented skeletal muscle atrophy in these animals.
Area of Science:
- Cardiology
- Exercise Physiology
- Pathology
Background:
- Chronic Chagas cardiomyopathy (CCC) results from Trypanosoma cruzi infection, causing inflammation, fibrosis, and impaired cardiorespiratory fitness (CRF).
- Myocardial perfusion abnormalities and histopathological changes characterize CCC progression.
Purpose of the Study:
- To assess the impact of aerobic physical training (APT) on myocardial perfusion.
- To evaluate APT's effects on inflammation, fibrosis, and functional impairments in CCC.
- To analyze skeletal muscle cross-sectional areas in response to APT in CCC.
Main Methods:
- Syrian hamsters with CCC and controls were divided into sedentary and APT groups.
- APT involved moderate-intensity exercise for 8 weeks.
- Assessments included echocardiography, myocardial perfusion scintigraphy, cardiopulmonary exercise testing, and histopathology.
Main Results:
- CCC animals showed progressive myocardial perfusion defects, reduced ejection fraction, and increased inflammation/fibrosis.
- APT significantly mitigated myocardial perfusion defects and reduced cardiac inflammation and fibrosis.
- APT improved cardiorespiratory fitness and preserved skeletal muscle cross-sectional area in CCC animals.
Conclusions:
- Aerobic physical training ameliorates cardiac dysfunction, myocardial perfusion defects, and reduces inflammation and fibrosis in a CCC hamster model.
- APT prevents skeletal muscle atrophy in CCC hamsters.
- Understanding APT's benefits is vital for future therapeutic strategies for CCC.
Background:
Chronic Chagas cardiomyopathy (CCC) is caused by an inflammatory process induced by Trypanosoma cruzi, which leads to myocarditis with reactive and reparative fibrosis. CCC progresses with myocardial perfusion abnormalities and histopathological events that affect cardiorespiratory fitness (CRF).
Objectives:
We evaluated the effects of aerobic physical training (APT) on myocardial perfusion and on morphological and functional impairments related with inflammation and fibrosis in Syrian hamsters with CCC. As a secondary objective, we analyzed the cross-sectional areas of the skeletal muscle.
Methods:
Hamsters with CCC and their respective controls were divided into four groups: CCC sedentary, CCC-APT, sedentary control and APT control. Seven months after infection, the animals underwent echocardiography, myocardial perfusion scintigraphy and cardiopulmonary exercise testing. Moderate-intensity APT was performed for fifty minutes, five times a week, for eight weeks. Subsequently, the animals were reassessed. Histopathological analysis was conducted after the above-mentioned procedures. The level of significance was set at 5% in all analyses (p<0.05).
Results:
CCC sedentary animals presented worse myocardial perfusion defects (MPD) over time, reduced left ventricle ejection fraction (LVEF) and showed more inflammation and fibrosis when compared to other groups (mixed ANOVA analysis). Conversely, APT was able to mitigate the progression of MPD, ameliorate inflammation and fibrosis and improve CRF efficiency in CCC-APT animals.
Conclusions:
Our study demonstrated that APT ameliorated cardiac dysfunction, MPD, and reduced inflammation and fibrosis in CCC hamster models. Additionally, CCC-SED animals presented skeletal muscle atrophy while CCC-APT animals showed preserved skeletal muscle CSA. Understanding APT's effects on CCC's pathophysiological dimensions is crucial for future research and therapeutic interventions.
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