RESUMO
Aim: To evaluate the effects of resistance exercise training (RET) and/or glutamine supplementation (GS) on signaling protein synthesis in adult rat skeletal muscles. Methods: The following groups were studied: (1) control, no exercise (C); (2) exercise, hypertrophy resistance exercise training protocol (T); (3) no exercise, supplemented with glutamine (G); and (4) exercise and supplemented with glutamine (GT). The rats performed hypertrophic training, climbing a vertical ladder with a height of 1.1 m at an 80° incline relative to the horizontal with extra weights tied to their tails. The RET was performed three days a week for five weeks. Each training session consisted of six ladder climbs. The extra weight load was progressively increased for each animal during each training session. The G groups received daily L-glutamine by gavage (one g per kilogram of body weight per day) for five weeks. The C group received the same volume of water during the same period. The rats were euthanized, and the extensor digitorum longus (EDL) muscles from both hind limbs were removed and immediately weighed. Glutamine and glutamate concentrations were measured, and histological, signaling protein contents, and mRNA expression analyses were performed. Results: Supplementation with free L-glutamine increased the glutamine concentration in the EDL muscle in the C group. The glutamate concentration was augmented in the EDL muscles from T rats. The EDL muscle mass did not change, but a significant rise was reported in the cross-sectional area (CSA) of the fibers in the three experimental groups. The levels of the phosphorylated proteins (pAkt/Akt, pp70S6K/p70S6K, p4E-BP1/4E-BP1, and pS6/S6 ratios) were significantly increased in EDL muscles of G rats, and the activation of p4E-BP1 was present in T rats. The fiber CSAs of the EDL muscles in T, G, and GT rats were increased compared to the C group. These changes were accompanied by a reduction in the 26 proteasome activity of EDL muscles from T rats. Conclusion: Five weeks of GS and/or RET induced muscle hypertrophy, as indicated by the increased CSAs of the EDL muscle fibers. The increase in CSA was mediated via the upregulated phosphorylation of Akt, 4E-BP1, p70S6k, and S6 in G animals and 4E-BP1 in T animals. In the EDL muscles from T animals, a decrease in proteasome activity, favoring a further increase in the CSA of the muscle fibers, was reported.
RESUMO
O propósito do presente estudo foi verificar os efeitos ou respostas fisiológicas relacionadas a pressão arterial sobre os exercícios resistidos. Foi analizado o comportamento da pressão arterial (utilizou se 80% de 1RM) durante e após a realização dos exercícios resistidos, o efeito da intensidade e variações de métodos. Os voluntários (n=9) realizaram dois métodos de treinamento o alternado por segmento (A.S.) e o localizado por segmento (L.S.), ou seja, os grandes grupos musculares de membro inferior e superior realizados seguidamente e posteriormente alternando os segmentos, com um período de descanso de um treino para o outro de 24 horas. Para comparar as diferenças entre os dois métodos de treinamento, o comportamento da pressão arterial no período pós-exercício suas alterações, magnitude e duração, utilizou-se para as variáveis mensuradas o teste-t de Student (p<0,05). Concluímos que não ocorreram diferença estatisticamente significativa no comportamento da pressão arterial durante a realização dos dois métodos, sendo apontada um hipotensão pós-exercício estatística em ambos, entretanto no método L.S. esta hipotensão com relação aos valores pressão arterial sistólica foi mais prolongada em comparação ao método A.S.
The purpose of this study was to verify effects or the physiological responses of blood pressure caused by strength exercises. Blood pressure behavior was analyzed, both during the execution of the exercise but (carried out at 80% of 1MR) during and after, the effect of the intensity and variations of the methods. Subjects (n = 9) were assembled to 2 different training methods, 1) alternating major groups of upper and lower extremities (Alternating Groups - A.G.) and 2) doing first major groups of upper extremities and then exercising major groups of lower extremities (Concentrating Groups - C.G.) with a rest period of 24 hours from one method to the other. In order to compare statistically the effects of both methods, on the magnitude and duration of blood pressure changes in the post exercise period, Students t test was used (p<0,05). We concluded that there were no differences in the blood pressure behavior when in the 2 different methods were compared, but we noticed a significant hypotension in both methods were last longer in the C.G. method when compared to A.G.
