Reversal of diet-induced insulin resistance with a single bout of exercise in the rat: the role of PTP1B and IRS-1 serine phosphorylation

Lifestyle interventions including exercise programmes are cornerstones in the prevention of obesity-related diabetes. In this study, we demonstrate that a single bout of exercise inhibits high-fat diet-induced insulin resistance. Diet-induced obesity (DIO) increased the expression and activity of the protein tyrosine phosphatase 1B (PTP1B) and attenuated insulin signalling in gastrocnemius muscle of rats, a phenomenon which was reversed by a single session of exercise. In addition, DIO was observed to lead to serine phosphorylation of insulin receptor substrate 1 (IRS-1), which was also reversed by exercise in muscle in parallel with a reduction in c-Jun N-terminal kinase (JNK) activity. Thus, acute exercise increased the insulin sensitivity during high-fat feeding in obese rats. Overall, these results provide new insights into the mechanism by which exercise restores insulin sensitivity.