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Previous issue date: 2014-02-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / 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 / Nosso objetivo foi investigar os efeitos de um programa de treinamento aer?bio
sobre o remodelamento adverso e precoce do ventr?culo esquerdo (VE), utilizando
modelo experimental de curto prazo de diabetes tipo 1 (DM1). Ratos Wistar foram
divididos em 4 grupos: controle sedent?rio (CS), controle treinado (CT), diab?tico
sedent?rio (DS) e diab?tico treinado (DT). O DM1 foi induzido por estreptozotocina
(45 mg/kg). O programa de treinamento consistiu em 4 semanas de corrida em
esteira (13 m/min, 60 min/dia, 5 dias/semana). Ao fim dos experimentos, os cora??es
foram coletados para analise da morfologia e do perfil transcricional do VE, com foco
em seu remodelamento. Os ?bitos foram registrados durante as 4 semanas.
Verificamos alta mortalidade entre os animais do grupo DS, enquanto que esta foi
significativamente reduzida no grupo DT. O grupo DS apresentou aumento na ?rea
de sec??o transversa dos cardiomi?citos e fibrose. O grupo DT exibiu redu??o das
medidas de trofismo card?aco, mas com rela??o ao conte?do col?geno, foi similar ao
grupo CS. As an?lises de express?o de genes ligados ao remodelamento card?aco
revelaram redu??o na express?o dos col?genos I e III, al?m de baixa express?o da
MMP-2, no grupo DS. O grupo DT apresentou diminui??o dos n?veis de mRNA para
MMP-9, e express?o g?nica de MMP-2 inalterada, se comparado ao grupo CS. As
express?es da MMP-2 e do TGF-1 foram aumentadas no grupo CT. A raz?o entre
express?o g?nica dos col?genos I e III mostrou-se elevada no grupo CT e reduzida
nos grupos diab?ticos. Esses resultados estabelecem altera??es precoces da
estrutura e do perfil transcricional do VE. Ainda, indicam que o treinamento aer?bio
exerce prote??o espec?fica contra mecanismos respons?veis pelo dano card?aco
observado no DM1
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/16741 |
| Date | 03 February 2014 |
| Creators | Silva, Flavio Santos da |
| Contributors | CPF:02817849906, http://lattes.cnpq.br/6391134710454943, Abreu, Bento Jo?o da Gra?a Azevedo, CPF:04052238621, http://lattes.cnpq.br/1725848357337658, Lago, Pedro Dal, CPF:46464662015, http://lattes.cnpq.br/9299796177039282, Bruno, Selma Sousa, CPF:44456042400, http://lattes.cnpq.br/4056770607573210, Dias, Fernando Augusto Lavezzo |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Fisioterapia, UFRN, BR, Movimento e Sa?de |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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