The effect of 12 weeks endurance training at 2 different intensities on GLUT4 mRNA expression of soleus and gastrocnemius muscles in obese mice

Abstract

The aim of this study was to investigate the expression of GLUT4 mRNA in soleus and gastrocnemius muscles in obese mice in response to endurance training. Forty male C57BL/6 mice were used in this study. Eight mice (Normal Base [NB]) served as non-obese non-trained controls, and 32 mice were put on a high fat diet (HFD) regimen (60%kcal fat) for 12 weeks. At week 16, the obese mice were randomized into the following treatment groups (n=8 each group): Obese Base [OB]; Low Intensity [LI]; High Intensity [HI]; or Obese Control [OC] groups. LI and HI trained for 5 days/week for 12 weeks on a motorized treadmill at 15m/min on a 5% slope (for LI), and/or at 22m/min on a 5% slope (for HI). OC mice were kept sedentarily in the cage during the training program. GLUT4 mRNA expression was measured in gastrocnemius and soleus muscles using a Real Time-PCR method. GLUT4 mRNA expression of soleus muscle in LI group increased about 2.2 fold, against about 1.6 fold for gastrocnemius (p<.05). In addition, GLUT4 mRNA expression of soleus and gastrocnemius muscles in LI and HI groups were significantly higher than OB and OC groups (p<.05). It can be concluded that any disturbance in body energy balance, especially by exercise training and/or high fat diet can influence these molecular and cellular mechanisms that act to establish a stable homeostasis.