Suplementação com proteína isolada de soja atenua dano muscular provocado pelo exercício em ratos Wistar

Abstract

Extenuating exercises or with very high intensities can generate undesirable processes like injuries in the muscular structure and elevation in the levels of biochemical markers of muscle damage. In this context, the objective of this study was to compare the effects of isolated soy protein, isolated soy protein with addition of leucine and isolated whey protein on the main markers of post-exercise muscle damage, knowing that the amino acid leucine is closely linked to protein synthesis, which consequently plays a role in muscle recovery. Wistar rats were divided into 3 groups: control whey protein isolate (WPI), isolated soy protein (SPI) + leucine and isolated soy protein. After four hours of fasting, the animals were submitted to the acute exercise in a weight-lifting model, and the effect of the protein compounds on the main markers of muscle injury in the blood was investigated. All animals were submitted to a considerable stress level and the group that consumed isolated soy protein had lower levels of CK-nac, CK-mb and LDH compared to the group that consumed only whey proteins, but did not differ significantly (p > 0.05) of the group receiving leucine addition soy protein isolate. For AST, ALT and total proteins there was no difference between groups. Muscle recovery involves several processes and to maintain homeostasis and adapt to physiological stress, this repair is dependent on positive nitrogen balance (synthesis greater than degradation). It is also known that leucine plays a key role in the activation of intracellular protein synthesis markers (mTOR). However, in the group that consumed isolated soy protein the levels of muscle damage were attenuated statistically higher than the whey protein and did not differ in the leucine addition group. That is, such results may be involved with the added amount and synergy with other amino acids that may have acted on the mechanism of protein resynthesis, and which may be influenced by the prolonged and constant aminoacidemia caused by the isolated soy protein.