Abstract:

BACKGROUND: Insulin resistance in the peripheral tissue is a major cause of type 2 diabetes mellitus.
OBJECTIVE: To observe the expression of protein tyrosine phosphatase 1B (PTP-1B) and insulin receptor substrate 2 (IRS-2) in the skeletal muscle of rats with insulin resistance induced by high-fat diet.
METHODS: Twenty SD rats were randomly divided into normal control group with 10 rats and high-fat diet group with 10 rats. Rats in the two groups were fed with normal diet and high-fat diet for 12 weeks, respectively.
RESULTS AND CONCLUSION: The insulin sensitive index was significantly decreased in the high-fat diet rats compared with the normal rats (P < 0.01). In obese rats, glucose tolerance and the acute first-phase insulin secretory response to glucose were impaired. The protein level of PTP-1B in the skeletal muscle of obese rats was significantly increased compared with the control group (P < 0.01). Insulin-stimulated IRS-2 phosphorylation in the skeletal muscle was reduced in the obese rats (P < 0.01). These indicate that the increased PTP-1B level and the reduced insulin-stimulated IRS-2 phosphorylations in the skeletal muscle seem to play an important role in the insulin resistance induced by high-fat diet.