Background and Aims:
We aimed at investigating the effect of aerobic exercise training (AET) in the insulin-resistance induced by low-sodium (LS) diet in LDLRKO mice focusing on the insulin-signalling in skeletal muscle.
Methods:
Three-month-old LDLRKO mice were fed a chow normal sodium (1,27%-NaCl; NS) or a LS (0,15%-NaCl; LS) diet, and concomitantly kept sedentary(S-NS; S-LS,) or submitted to AET (T; T-NS; T-LS) (treadmill 1h/day, 15 m/min, 5-times week) during 3 months. Exercise capacity, body weight (BW), blood pressure (BP), plasma cholesterol (TC), triglycerides (TG), fasting glucose (FG) and glucose decay rate by the insulin tolerance test (ITT) were determined. GLUT4, total and phosphorylated AKT in whole gastrocnemius extract were analyzed by immunoblot. Comparisons were done by 2-way ANOVA.
Results
AET increased the exercise capacity in trained mice. BW, BP and TC were similar among groups. TG (mg/dL) was increased by LS diet (S-NS 101±9; T-NS 100±26; S-LS 152±36; T-LS 130±50; p=0.0284).There was an effect of the LS diet (p=0.0224) and AET (p=0.0477) on FG (S-NS 101±15; T-NS 113±15; S-LS 115±19; T-LS 124±23). A diminished rate of glucose disappearance was induced by LS diet that was prevented by AET (diet effect, p=0.0153; AET effect,p=0.0183; interaction,p=0.0218). The amount of GLUT4 (p=0.0130), total AKT (p= 0.0086) and phosphorylated AKT (p=0.0058) were increased (19, 20 and 22%, respectively) by the AET effect without with no significant effect of diet.
Conclusions:
AET prevents the LS diet-induced insulin resistance in LDLRKO mice by enhancing total and phosphorylated AKT and GLUT4 content in skeletal muscle.

03 - AEROBIC EXERCISE TRAINING COUNTERACTS INSULIN RESISTANCE INDUCED BY LOW SODIUM DIET BY INCREASING INSULIN SIGNALING IN MUSCLE