mohammad sharif bagheri

Exercise and diabetes have opposite effects on GLUT4 protein, but its mechanism has not been fully investigated. This study aimed to investigate the effect of six weeks of endurance training on protein levels of GLUT4 and HDAC5 in extensor digitorum longus (EDL) muscle in diabetic rats.

32 male Wistar rats (weight: 245±9.4 g) were randomly divided into 4 groups: Control, exercise, diabetic, diabetic-exercise. At 8 weeks of age, diabetes was induced by streptozotocin. The endurance training was performed for 6 weeks. 24 hours after the last session, the mice were sacrificed and EDL muscle was extracted. The protein levels of GLUT4 and HDAC5 were measured using ELISA method. One-way ANOVA was used to analyze the data at a significant level of P<0.05.

Results showed significant differences in GLUT4 levels between control and diabetic (P=0.0005), diabetic-exercise and diabetic (P=0.0005) and diabetic and exercise groups (P=0.0005). Also, the results showed that there was no significant difference in HDAC5 protein levels between control and exercise (P=0.138), diabetic-exercise and diabetic (P=0.229) and exercise and diabetic groups (P=0.306), and there was a significant difference between the other groups (P<0.05). Also, There was a non-significant inverse relationship between GLUT4 and HDAC5 protein levels (r=-0.169, P=0.354).

The positive effect of endurance training on GLUT4 protein levels was greater in the diabetic than in the healthy group. Although endurance training had a positive effect on GLUT4 and HDAC5 levels and effect on GLUT4 protein was greater and more significant.

Increased expression of HDAC5 reduces the expression of GLUT4 in slow-twitch fibers, and this mechanism has not been studied in diabetes. Therefore, the purpose of study was to investigate the effect of six weeks endurance training on protein levels of GLUT4 and HDAC5 in soleus muscle in diabetic rats.

For this purpose, 32 male Wistar rats (weight: 245±9.4 g) were randomly divided into 4 groups: diabetic, diabetic and training, training, and control. At 8 weeks of age, diabetes was induced by streptozotocin. The endurance training was carried out five times per week for 6 weeks. 24 hours after the completion of the protocol, the mice were sacrificed and their soleus muscle was extracted. Then, the protein levels of GLUT4 and HDAC5 were measured using ELISA method. One-way ANOVA was used to analyze the data at a significant level of P<0.05.

Results showed significant differences between control and training (P=0.008), training and diabetic training (P=0.004), and training and diabetic (P=0.0005) groups in GLUT4 levels. But, in HDAC5, results showed that there is not significant differences only between control and training groups (P=0.99), and there are significant differences among other groups (P<0.05). Also, there is a significant inverse relationship between the protein levels of GLUT4 and HDAC5 (P=0.012, r =-0.439).

It seems that six weeks moderate intensity endurance training increases protein levels of GLUT4. But endurance training only can decreases protein levels of HDAC5 in diabetes.