Malondialdehyde and cardiac troponin I in Arabian horses subjected to exercise and vitamin E supplementation/Malondialdeido e troponina I cardiaca em equinos da raca Puro Sangue Arabe submetidos ao exercicio e a suplementacao com vitamina E

• Published in: Ciência rural 2010-06, Vol.40 (6), p.1321
• Main Authors: Yonezawa, Leticia Andreza, Machado, Luciana Pereira, da Silveira, Veridiana Fernandes, Watanabe, Marcos Jun, Saito, Mere Erika, Kitamura, Sandra Satiko, Kohayagawa, Aguemi
• Format: Article
• Language: Spanish
• Subjects: Electrocardiography; Physiological aspects; Troponin; Vitamin E
• ISSN: 0103-8478

To evaluate the effect of exercise, training and vitamin E supplementation on serum malondialdehyde (MDA) and cardiac troponin I (cTnI), sixteen adult untrained Arabian horses were divided into 2 groups of 8 animals each, control and supplemented with vitamin E. Both groups had incremental exercise tests performed on a high-speed treadmill at a +7% slope, before (P1) and after (P2) a training period of 20 days. Serum concentrations of MDA, vitamin E and cTnI, and resting electrocardiogram were performed before and after P1 and P2. Results suggested that oxidative stress was induced by exercise as measured by serum MDA increase. In some animals, there was a subtle increase in cTnI concentration associated with the detection of ventricular premature complexes, which didn't represent a significant cardiac injury. There was no training effect on oxidative stress. It was concluded that, under the conditions above, the incremental exercise promoted lipoperoxidation, which was not prevented by vitamin E supplementation or training, however, it was not enough to cause a significant cardiac damage. Key words: oxidative stress, cardiac metabolism, horse, sports medicine. Para avaliar o efeito do exercicio fisico, do treinamento e da suplementacao com vitamina E sobre o malondialdeido (MDA) e a troponina I cardiaca (cTnI) sericos, foram utilizados 16 equinos da raca Puro Sangue Arabe, sem treinamento, divididos em dois grupos de oito: controle e suplementado com vitamina E. Ambos os grupos foram submetidos a provas de exercicio progressivo em esteira de alta velocidade inclinada a +7%, antes (P1) e apos (P2) o periodo de treinamento de 20 dias. Foram determinadas as concentracoes sericas de MDA, vitamina E e cTnI e realizou-se o eletrocardiograma de repouso antes e apos as provas P1 e P2. Os resultados sugerem a ocorrencia do estresse oxidativo ocasionado pelo exercicio, determinado por meio do aumento de MDA serico. Em alguns animais, houve um discreto aumento de cTnI associado a deteccao de complexos ventriculares prematuros, mas que nao representou lesao cardiaca expressiva. Nao houve efeito do treinamento sobre o estresse oxidativo. Portanto, e possivel concluir que o exercicio fisico progressivo promoveu a lipoperoxidacao nessas condicoes, que nao foi prevenida pela suplementacao com vitamina E nem pelo treinamento, mas nao foi suficiente para causar uma lesao cardiaca significativa. Palavras-chave: estresse oxidativo, metabolismo cardiaco, cavalo, medicina espo