AnÃlises histolÃgicas e proteÃmicas do miÃcito cardÃaco de ratos submetidos a diferentes intensidades de exercÃcio

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Scientific literature have been described the regular which as an important factor in the health improvement. Among several causes have been related to this phenomenon, it was observed a crucial point that included the improvement of heart potency. This enhancement could be related to several factors such as cardiac muscle cells hypertrophy, which was considered the most important hearth adaptable process in response to physical exercise, being directly related to contractile force development in cardiac cells. Muscle contractile capability could be generated by an interaction between different proteins, including myosin; the biggest muscle protein formed by heavy (MHC) and light (MLC) chains. In summary, the present study aims to establish a clear relation between different load levels and the increase of myosin heavy chain expression in cardiac contractile cells of R. novergicus through proteomics techniques. Moreover, data here reported could be used to shed some light over the standard physical exercise procedures in order to give a most efficient result in sport performance and/or therapeutic procedures. To evaluate this question, 40 isogenics adult male rats Wistar (R. norvergicus) were divided into three groups TG1, TG3 and TG3. Groups were submitted to swimming training during twelve weeks, 2.5%; 5.0% and 7.5% of individualized overload. The animals from training groups GT1, GT2 had been submitted the continuous exercise and the animals pertaining of TG3 were submitted the interval exercise. Furthermore, our findings demonstrated clear morphologic alterations in hearth animals submitted to physical training (TGs), when compared to control group (CG). A discrete degree of nuclear hypertrophy was evidenced in GT3, suggesting that the intrinsic contractile characteristics of myofibrils could be modified in order to contribute for an increase of left ventricle activity, being this event associated to the training. Additionally, significant differences in protein maps were observed, by using one and two dimensional electrophoresis technologies, following mass spectrometry identification. All treatments clearly demonstrated the MHC expression increase in comparison to CG. Finally, the improvement of other proteins were also evaluated as troponin, a sarcomeric protein, proteins associated to oxidative metabolism as oxidorecdutases, translocases of mitochondrial membrane and proteins analogous to superoxide desmutases. This increase suggests a clear correlation with standard intensity in which each one of the individuals was submitted, demonstrating that high intensity interval training, when compared to continuous training of low and moderate intensity, was more efficient in the MHC enhancing expression in cardiac contractile cells. Furthermore, the high intensity also caused a significant degree of cellular injury, when compared with the rats submitted to low intensity. This process could, during a large period, lead to losses of contractile ability and consequently, to a functional reduction. In summary, these findings give support for more precise training programs such sports or health, also offering subsidies for the development of novel electrophoresis techniques approaches in order to carry high molecular weight proteins analysis.

ASSUNTO(S)

exercÃcios fÃsicos proteins analysis - metabolism peso muscular fisiologia cardiovascular coraÃÃo - hipertrofia

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