ABSTRACT
Abstract AIMS knowing the relationship between endoplasmic reticulum (ER) stress and inflammation and based on the fact that downhill running-based overtraining (OT) model increases hypothalamus levels of some pro-inflammatory cytokines, we verified the effects of three OT protocols on the levels of BiP, pIRE-1 (Ser734), pPERK (Thr981), pelF2alpha (Ser52), ATF-6 and GRP-94 proteins in the mouse hypothalamus after two weeks of recovery. METHODS the mice were randomized into control (CT), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR) groups. After 2-week total recovery period (i.e., week 10), hypothalamus was removed and used for immunoblotting. RESULTS the OTR/down group exhibited high levels of BiP and ATF6. The other OT protocols showed higher levels of pPERK (Th981) and pelf-2alpha (Ser52) when compared with the CT group. CONCLUSION the current results suggest that after a 2-week total recovery period, the overtrained groups increased partially their ER stress protein levels, but without hypothalamic inflammation, which characterizes a physiological condition related to an adaptation mechanism.(AU)
Subject(s)
Animals , Male , Mice , Adaptation, Physiological , Endoplasmic Reticulum , Exercise , Hypothalamus , Mice, Inbred C57BLABSTRACT
Abstract AIMS Previously, we verified that overtrained mice upregulated the TRB3 levels, its association with Akt, and the hepatic concentrations of glycogen. It is known that APPL1 can limit the interaction between TRB3 and Akt, playing an important role in the glucose homeostasis. Thus, we verified the effects of three overtraining protocols on the hepatic levels of APPL1 and APPL2. METHODS Rodents were divided into control (CT), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR). The hepatic contents of APPL1 and APPl2 were measured by the immunoblotting technique. RESULTS Significant elevation of APPL1 observed in the OTR/down and OTR/up groups, as well as the tendency of increase (p=0.071) observed in the OTR group. CONCLUSION These results indicate that this particular protein is likely to participate in the glucose homeostasis previously observed in response to these OT protocols.(AU)
Subject(s)
Animals , Male , Mice , Adaptation, Physiological/physiology , Adaptor Proteins, Signal Transducing/metabolism , Hemostasis/physiology , Insulin/metabolism , Liver/physiology , Resistance Training , Mice, Inbred C57BLABSTRACT
INTRODUÇÃO: A deficiência na captação de glicose em tecidos periféricos e o aumento da gliconeogênese hepática são fenômenos fisiopatológicos observados em pacientes diabéticos do tipo 2. O exercício físico é considerado um importante aliado para a melhora do perfil glicêmico em pacientes diabéticos; entretanto, os mecanismos envolvidos nesse processo não estão completamente elucidados. OBJETIVO: Avaliar o papel da proteína AMPK no controle glicêmico em camundongos diabéticos após o exercício físico. MÉTODOS: Durante o jejum, o teste de tolerância à insulina (ITT) e a técnica de Western blot foram combinados para avaliar a homeostase da glicose em camundongos diabéticos (ob/ob e db/db) submetidos a uma única sessão de natação. RESULTADOS: A hiperglicemia de jejum, a severa resistência à insulina e a deficiência na sinalização da via AMPK/ACC no músculo e no fígado observadas nos camundongos diabéticos foram revertidas após a sessão de exercício. A restauração da via AMPK/ACC reduziu a expressão da enzima gliconeogênica PEPCK no fígado e aumentou a translocação do GLUT4 no músculo esquelético. Esses dados apontam que a ativação da via AMPK/ACC induzida pelo exercício físico é importante para a redução da glicemia de jejum em modelos experimentais de diabetes tipo 2. Esses dados abrem novas frentes para o entendimento de como a atividade física controla da homeostase da glicose em pacientes diabéticos.
INTRODUCTION: The deficiency in glucose uptake in peripheral tissues and increased hepatic gluconeogenesis are physiopathological phenomena observed in type 2 diabetes patients. Physical exercise plays an important role in the improvement of glycemic profile in diabetic patients; however, the mechanisms involved in these processes have not been fully elucidated. OBJECTIVE: to assess the role of AMPK protein in the glycemic control of diabetic mice after exercise. METHODS: During fasting condition, the insulin tolerance test (ITT) and Western blot technique, were combined to assess the glucose homeostasis in diabetic mice (ob/ob and db/db) after a single swimming session. RESULTS: Fasting hyperglycemia, severe insulin resistance and deficiency in the AMPK/ACC signaling in muscle and liver observed in the diabetic mice were reversed after the exercise session. The restoration of AMPK/ACC signaling reduced the expression of the gluconeogenic enzyme, PEPCK in the liver, and increased the translocation of GLUT4 in the skeletal muscle. These data indicate that the activation of AMPK/ACC pathway induced by physical exercise is important to reduce fasting glucose levels in experimental models of type 2 diabetes. These data open new insights for determination of physical activity control on the glucose homeostasis in diabetic patients.