Title: The effect eight weeks of high intensity interval training and moderate intensity continuous training on the gene expression of SIRT3 and HSP70 in heart tissue of diabetic male Sprague Dawley rats obesed by high-fat diet.

The effect of exercise training in control of diabetes has been proved, but comparison of the effect of high intensity interval training (HIIT) and moderate intensity continuous training (MICT) on the protective mechanisms of heart tissue is still not well known. So, the aim of this study was to compare the effect of HIIT and MICT on the Sirtuin-3 (SIRT3) and Heat shock protein-70 (HSP70) gene expression in heart tissue of high-fat diet and diabetic rats.

eighteen male Sprague Dawley rats were fed with high-fat diet for three months. After that, diabetes was induced by injecting 30 mg/kg streptozotocin intra peritoneally. Then the rats were divided into 3 groups of 6 rats including, HIIT, MICT, and control. Also, 6 rats were considered to investigate the effect of high-fat diet and diabetes on research variables in the healthy control group. During 8 weeks training protocol, the HIIT group performed 6 training sessions in the first week to 12 training sessions in the last week training sessions with intensity of 80-85% of the maximum speed. MICT group was run 50 to 55% of the maximum running speed which lasted from 25 minutes in the first week to 50 minutes in the final week. Finally, SIRT3 and HSP70 gene expression values ​​were measured in heart tissue by qRT-PCR method. One-way analysis of variance (ANOVA) test was used to analyze the data (P<0.05).

SIRT3 gene expression levels in the HIIT and MICT groups were significantly higher than the control group (P=0.001) and HSP70 gene expression levels in the HIIT group were lower than the control group (P=0.01). In addition, no significant difference was observed in SIRT3 and HSP70 values ​​in HIIT and MICT training (P≤0.05).

It seems that HIIT and MICT play a role in improving mitochondrial function by increasing SIRT3 expression; However, considering the decrease in HSP70 levels following HIIT, it seems that more studies with the approach of cell damage following high-intensity training are needed.