Effect of ۸-Week Interval Training on Protein Tyrosine Phosphatase ۱B Expression in Gastrocnemius Muscle and Insulin Resistance in Rats with Type ۲ Diabetes

Background: Insulin resistance induced by genetic and metabolic disorders is the main cause of the prevalence or severity of type ۲ diabetes (T۲D). Protein tyrosine phosphatase ۱B (PTP۱B) plays a key role in regulating glucose homeostasis as a negative regulator of insulin signaling pathway. Objectives: This study aimed to assess the effect of interval training on PTP۱B expression in gastrocnemius muscle and insulin resistance in male rats with T۲D. Methods: T۲D was induced by high fat diet (HFD) and intraperitoneal injection of STZ in ۱۴ male Wistar rats and then they were divided randomly into exercise (n=۷) or control (n=۷) groups. Exercise rats completed an ۸ weeks interval training (۵ days/week) and control rats remained without training. Fasting glucose, serum insulin, and PTP۱B expression in gastrocnemius muscle were measured ۴۸ hours after the last exercise session. Insulin resistance was assessed using homeostasis model assessment of insulin resistance (HOMA-IR) formula based on fasting insulin and glucose levels. An independent t test was used to compare each parameter between ۲ groups. A P value less than ۰.۰۵ was considered statistically significant. Results: Interval training resulted in a significant decrease in fasting glucose level (P<۰.۰۰۰۱) and insulin resistance (P=۰.۰۱۸) as well as an increase in serum insulin level (P<۰.۰۰۰۱). PTP۱B expression in gastrocnemius muscle decreased significantly compared with control rats (P=۰.۰۰۳) Conclusion: Interval training can improve insulin resistance in T۲D rats. This improvement may be attributed to the decrease in PTP۱B expression in gastrocnemius muscle by interval training.