Efeitos cardiovasculares da associação do hormônio tireoidiano e do exercício físico em ratos Wistar

• Autor(a) principal: Souza, Fernanda Rodrigues de
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFU
• Texto Completo: https://repositorio.ufu.br/handle/123456789/12770; https://doi.org/10.14393/ufu.di.2013.161
• topic: Hipertireoidismo; Hipertrofia cardíaca; Exercício físico; Hormônios tireoidianos; Exercícios físicos - Aspectos fisiológicos; Coração - Hipertrofia; Hyperthyroidism; Cardiac hypertrophy; Physical exercise; CNPQ::CIENCIAS DA SAUDE

Introduction: The hyperthyroidism produces hemodynamic changes and cardiac hypertrophy, however, many of their characteristics and effects of its association with physical exercise are not clear. Objective: Evaluating the cardiovascular effects of the association of thyroid hormone and physical exercise in rats. Methods: We used 37 adult male rats weighing approximately 250 grams were randomly divided into four groups: control (C), exercise (E), thyroid hormone (TH), thyroid hormone and exercise (H + E). The animals of the groups TH and H+E thyroid hormone received by gavage, a dose of 20 μg /100 kg of body weight, daily for six weeks. The animals of groups E and H + E exercise performed five times per week for six weeks. The control group did not undergo any intervention. The groups were compared in terms of T3 and T4, body weight, exercise tolerance, heart rate, blood pressure systolic, total heart weight, left ventricular weight, transverse diameter of cardiomyocytes and percentage of collagen. To compare the above variables were used the t test, Wilcoxon, ANOVA complemented by Tukey test and the Pearson correlation. Results: The T4 levels were elevated in TH e H+E groups. Body weight was higher in all groups after the treatment. Exercise tolerance was higher in group H + E. The total weight of the heart was higher in the groups receiving thyroid hormone. The ventricular weight was higher in the TH group. The transverse diameter of cardiomyocytes showed higher values in the groups TH, E and H+E comparing to C group, the highest values were obtained in the TH group. The percentage of collagen was higher in groups E and H+E. There was a positive correlation. The variables in the group C showed a positive correlation between total weight of the heart and left ventricular weight (r = 0.74). The TH group, showed a positive correlation only between the transverse diameter of cardiomyocytes and total weight of the heart (r = 0.70). The group E had a positive correlation between left ventricular weight and the total weight of the heart (r = 0.67), and between the percentage of collagen and the left ventricular weight (r = 0.795) and showed a negative correlation between transverse diameter of cardiomyocytes and left ventricular weight (r = 0.62) and between the percentage of collagen and transverse diameter of cardiomyocytes (r= 0.67). In the group H + E there was a positive correlation between the left ventricular weight and the total weight of the heart (r = 0.80) and between the transverse diameter of cardiomyocytes and the left ventricular weight (r = 0.71). Conclusion: The association of thyroid hormone with high-intensity exercise produced cardiac hypertrophy characterized by increased weight of the heart and transverse diameter of cardiomyocytes without concomitant increase in the weight of the left ventricle. The pattern of association of hypertrophic thyroid hormone and exercise was not directly correlated with the degree of fibrosis.