masterThesis
Efeitos do treinamento aeróbio sobre sinais precoces do remodelamento do ventrículo esquerdo induzido pelo diabetes Mellitus experimental
Fecha
2014-02-03Registro en:
SILVA, Flavio Santos da. Efeitos do treinamento aeróbio sobre sinais precoces do
remodelamento do ventrículo esquerdo induzido pelo diabetes
Mellitus experimental. 2014. 63 f. Dissertação (Mestrado em Movimento e Saúde) - Universidade Federal do Rio Grande do Norte, Natal, 2014.
Autor
Silva, Flavio Santos da
Resumen
Our aim was to investigate the effects of an aerobic training program on adverse and
early left ventricle (LV) remodeling, using an experimental model of short-term type 1
diabetes (T1D). Wistar rats were divided in 4 groups: sedentary control (SC), trained
control (TC), sedentary diabetic (SD) and trained diabetic (TD). T1D was induced by
streptozotocin (45 mg/kg). The training program consisted of 4 weeks running on a
treadmill (13 m/min, 60 min/day, 5 days/week). At the end of the experiments, hearts
were collected for analysis of morphology and transcriptional profile of LV, by
focusing on its remodeling. Deaths were recorded during the 4-week period. We
verified high mortality among animals of DS group, whereas it was significantly
reduced in DT group. DS group also showed an increase in cross-sectional area of
cardiomyocytes and fibrosis. TD group exhibited reduction in measures of cardiac
trophism, but with respect to collagen content, it was similar to CS group. Analysis of
gene expression related to cardiac remodeling revealed decreased expression of
collagen I and III, as well as low expression of MMP-2 in DS group. TD group
showed decreased levels of mRNA for MMP-9, and unchanged gene expression of
MMP-2 when compared with the CS group. The expression of MMP-2 and TGF-1
were increased in CT group. The ratio between gene expression of collagen I and III
was increased in the CT group and decreased in diabetic groups. These results
establish early changes of the structure and transcriptional profile of LV myocardium.
Moreover, they indicate that aerobic exercise training plays specific protection
against mechanisms responsible for cardiac damage observed in T1D