ABSTRACT
OBJECTIVE: This study aimed to compare the effect of different physical training on the mechanism of ceramidedependent insulin resistance in the flexor hallucis longus (FHL) muscle of diabetic rats. MATERIALS AND METHODS: In this experimental study, 7 healthy as a healthy control (HC) group, and 21 diabetics (55 mg/ kg Streptozotocin) Wistar rats (200-220 g; 8-10 weeks old) divided into the diabetic control (DC), moderate continuous training (MCT), and moderate intensity interval training (MIIT) groups. Both MCT (55-70% of maximal oxygen uptake (VO2max), and MIIT (85% VO2max) groups trained for 10-25 minutes at a speed of 10-20 m/minutes. The changes in the expression of blood glucose, insulin, insulin resistance, lipid profile and total ceramide were measured as well as ceramide synthase-1, Glucose transporter type 4 (GLUT4), Protein kinase B known as Akt, phosphorylated protein kinase B known as pAkt, protein kinase C (PKC), and tumour necrosis factor α (TNFα). RESULTS: Blood glucose, triglyceride (TG) and ceramide synthase-1 (CS1) expression levels in the MCT group decreased in comparison with the DC group. FHL protein expression of GLUT4 in the MCT group was higher than the DC group. FHL expression of GLUT4, pAKT, AKT/pAKT, PKC, CS1 and total ceramide in the MIIT group were higher than the DC group. Cholesterol, low-density lipoprotein (LDL), TG, and TNF-α protein expression in the MIIT group were lower than the DC group. GLUT4, PKC, pAKT, AKT/pAKT in the MIIT group were higher, and total ceramide and TNF-α were lower in the MIIT group than the MCT group. CONCLUSION: It seems that both training plan MIIT and MCT have favorable effects on the metabolism of glucose, insulin, lipids, and the decrease of TNFα level in the diabetes, but in connection with the improvement of the ceramides mechanism, it seems that the MIIT training plan is more optimal than MCT training plan.
ABSTRACT
The research literature suggests that different training modalities cause various patterns in training-induced genes expression. This study aimed to investigate the effects of moderate intensity continuous training (MICT) and isocaloric high intensity interval training (HIIT) on gene expression of monocarboxylate transporter 1 (MCT1) and 4 (MCT4), Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), and hypoxia inducible factor-1α (HIF-1α) in soleus and extensor digitorum longus (EDL) skeletal muscles of rats. Thirty male Sprague-Dawley rats were divided into 3 groups of control, MICT, and HIIT. Training protocols were performed according to the principle of overload for 8 weeks and 5 sessions per week. Then, the soleus and EDL muscles were extracted and the expression levels were analyzed using the real time PCR method. In the MICT group, only the EDL HIF-1α mRNA level was significantly higher than that of the control group (p < 0.05). In the HIIT group, however, mRNA levels of MCT4, PGC-1α, and HIF-1α in both muscles were significantly higher than those of the control group (p < 0.05). The comparison between the two training methods demonstrated that the gene expression levels of soleus and EDL MCT4, soleus PGC-1α, and soleus HIF-1α were significantly higher in the HIIT group compared to the MICT group (p < 0.05). There were also significant positive correlations between all mRNA levels of HIF-1α and corresponding mRNA levels of MCT4 (p < 0.05). HIIT caused greater positive responses in the gene expression of MCT4, PGC-1α, and HIF-1α compared to MICT.
