The Effect of Training Type on The Signaling P athway of Ceramide-Dependent Insulin Resistance in The Flexor Hallucis Longus Muscle of Streptozotocin-Induced Diabetic Rats

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.

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).

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.

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.