Comparison of the effects of two types of high intensity interval training on the gene expression of collagen 1, 2, and SMAD/3 in the left ventricle of male rats in type 2 diabetes induced by streptozotocin

High-intensity interval training reduces diabetic cardiomyopathy by regulating gene expression in patients with diabetes. The aim of this study was to compare the effect of two types of high intensity interval training on the expression of collagen 1, 2 and SMAD/3 genes in the left ventricle of male rats with type 2 diabetes.

The present study was experimental. For this purpose, 28 male Wistar rats were divided into four groups: type 1 high-intensity interval training (HIIT1:1), type 2 high-intensity interval training (HIIT2:1), diabetic control (DC), and non-diabetic control (NC). Diabetes was induced in all groups except non-diabetic control group by intraperitoneal injection of streptozotocin (STZ) after 12 hours of overnight fasting. 24 hours after the last training and recovery session, their left ventricle was extracted. Plasma glucose concentration was measured by the glucose oxidase method, ELISA method was used to measure the insulin levels, and the HOMA-IR method was used to measure the insulin resistance index. A real-time PCR technique was used to evaluate the gene expression of the collagens 1 , 2 , and SMAD/3 genes. Results were analyzed with one-way ANOVA and Tukey post hoc tests.

Collagen 1 did not show a significant difference between the two exercise groups (p = 0.112). The mean values of both exercise groups were significantly lower than in the diabetic control group in collagen expression (p = 0.0001). The mean values of collagen 2 gene expression in the HIIT2: 1 training group were significantly lower than the HIIT1: 1 group (P = 0.044) and diabetic control (P = 0.002). The mean values of SMAD / 3 gene expression in HIIT2: 1 group were significantly lower than HIIT1: 1 (P = 0.002) and diabetic control (P = 0.020). The mean weight values and insulin resistance index in the HIIT1 group and glucose in the HIIT2: 1 group were significantly lower.

Based on the findings, it can be concluded that 4 weeks of type 2 HIIT compared to other groups had a higher effect on reducing the expression of collagen 2 and SMAD / 3 genes in the left ventricle of diabetic rats with down-regulated of genes. Therefore HIIT-2  may improve diabetic cardiomyopathy syptoms.