Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
Effect of mild aerobic training on the myocardium of mice with chronic Chagas disease.
Preto E
,
Lima NE
,
Simardi L
,
Fonseca FL
,
Filho AA
,
Maifrino LB
.
???displayArticle.abstract???
BACKGROUND: Chronic chagasic heart disease represents extensive remodeling of the cardiovascular system, manifested as cardiac denervation, interstitial mononuclear infiltrate, myocyte and vascular degenerative changes, fibrosis, and hypertrophy. Moreover, aerobic exercises are widely indicated for the treatment of various disorders of the cardiovascular system.
PURPOSE: To evaluate the right and left ventricles of BALB/c mice with chronic Chagas disease, undergoing mild exercise, by using morphometric and stereological methods.
MATERIALS AND METHODS: A total of 20 male mice at 4 months of age were used for experiments. The animals were divided into four groups (n=5 in each group): untrained control, trained control, untrained infected (UI), and trained infected (TI). Animals of UI and TI groups were inoculated with 1,000 trypomastigote forms of Trypanosoma cruzi (Y strain), and after 40 days, animals entered chronic phase of the disease. Physical exercise, which included swimming, was performed for 30 minutes daily, five times a week for 8 consecutive weeks at a bath temperature of 30°C. After the trial period, euthanasia and subsequent withdrawal of the heart were done. The organ was prepared by histological staining procedures with hematoxylin-eosin and picrosirius red.
RESULTS: We found that the physical training used in our experimental model promoted increase in volume density of capillaries and decrease in volume density of collagen fibers and cross-sectional area of cardiomyocytes in chagasic animals (TI group). By histopathological analysis, we found differences in the inflammatory infiltrate, which was lower in animals of TI group. The training program promoted a recovery of these parameters in the TI group.
CONCLUSION: Our results suggest that low-intensity aerobic exercise acts on morphological and morphometric parameters of the left and right ventricles in mice infected with T. cruzi, reducing the changes caused by the organism and making the results comparable to those of the uninfected control group.
Figure 1. Photomicrographs of transverse histological sections of myocardium from animals in the studied groups (hematoxylin–eosin stain).Notes: (A) untrained control; (B) trained control; (C) untrained infected; (D) trained infected. (A) The characteristic homogenous structure seen in control. (B) Myocyte hypertrophy evidenced by karyomegaly and hyperchromatic nuclei (thin arrow) and decreased inter-beam space (thick arrow). (C) Beam of more spaced muscle fibers (thin arrow), moderate mononuclear inflammatory infiltrate with presence of mast cells (arrowhead). There is edema and mild diffuse fibrosis (thick arrow). (D) Absence of inflammatory infiltrate, increased spaces between muscle beams (thick arrow) and myocyte hypertrophy characterized by karyomegaly and hyperchromatic nuclei (thin arrow).
Figure 2. Photomicrographs of longitudinal sections of the myocardium stained by picrosirius red, viewed through polarized light.Notes: (A) Untrained control; (B) trained control; (C) untrained infected; (D) trained infected. Note the birefringent collagen fibers (arrows) and their arrangement in the cardiac muscletissue. Check the increase in collagen fibers in the untrained infected group (C) compared to trained infected group (D).
BRENER,
Therapeutic activity and criterion of cure on mice experimentally infected with Trypanosoma cruzi.
1962, Pubmed
BRENER,
Therapeutic activity and criterion of cure on mice experimentally infected with Trypanosoma cruzi.
1962,
Pubmed
Barbosa-Ferreira,
Leptin in heart failure.
2013,
Pubmed
Biolo,
Chagas cardiomyopathy--where do we stand after a hundred years?
2010,
Pubmed
Carod-Artal,
Chagas disease and stroke.
2010,
Pubmed
Carod-Artal,
Stroke in asymptomatic Trypanosoma cruzi-infected patients.
2011,
Pubmed
Chrysohoou,
The association between physical activity and the development of acute coronary syndromes in treated and untreated hypertensive subjects.
2003,
Pubmed
Fialho,
Effects of an exercise program on the functional capacity of patients with chronic Chagas' heart disease, evaluated by cardiopulmonary testing.
2012,
Pubmed
Gazoti Debessa,
Age related changes of the collagen network of the human heart.
2001,
Pubmed
Kokkinos,
Exercise as hypertension therapy.
2001,
Pubmed
Mandarim-de-Lacerda,
Stereological tools in biomedical research.
2003,
Pubmed
Marin-Neto,
Pathogenesis of chronic Chagas heart disease.
2007,
Pubmed
Marques,
Exercise training attenuates cardiovascular adverse remodeling in adult ovariectomized spontaneously hypertensive rats.
2006,
Pubmed
Moreira,
Physical exercise protects myenteric neurons and reduces parasitemia in Trypanosoma cruzi infection.
2014,
Pubmed
Morvan,
Metabolic, hemodynamic and structural adjustments to low intensity exercise training in a metabolic syndrome model.
2013,
Pubmed
Novaes,
Trypanosoma cruzi infection induces morphological reorganization of the myocardium parenchyma and stroma, and modifies the mechanical properties of atrial and ventricular cardiomyocytes in rats.
2013,
Pubmed
Novaes,
Effects of Trypanosoma cruzi infection on myocardial morphology, single cardiomyocyte contractile function and exercise tolerance in rats.
2011,
Pubmed
Rassi,
Chagas disease.
2010,
Pubmed
Schebeleski-Soares,
Preinfection aerobic treadmill training improves resistance against Trypanosoma cruzi infection in mice.
2009,
Pubmed
Tassi,
Relationship between fibrosis and ventricular arrhythmias in Chagas heart disease without ventricular dysfunction.
2014,
Pubmed