Abstract:

Abstract:Objective
To investigate the changes of the expression of corticosteroids metabolic enzymes  11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) and glucocorticoid receptor (GR) in skeletal muscle in type 2 diabetic rat  model and significance. Methods The Wistar rats were devided into control and type 2 diabetic model groups. The models were built  with a combination of high fat diet (HFD) and multiple low dose of STZ (30 mg/kg, twice) injection. 8 weeks later, the blood of rats were colleted by cutting their tail，the blood glucose was tested with the method of oxidizing enzyme. According to the serologic test and the relevant index of insulin, the damage of islet and the secretion of insulin were determined. The protein expressions of corticosteroids metabolic enzymes 11β-HSD1 and GR in skeletal muscle were examined by Western blotting analysis. Results  Compared with control group, the insulin secretion(IS), insulin sensitivity index(ISI) and secretion index of HOMA β cell (HβCI) were decreased significantly(P<0.05), while the insulin resistance index (IRI) was increased significantly(P<0.05). The protein expressions of 11β-HSD1 and GR in model group were higher than those in control group(P<0.05). Conclusion The type 2 diabetic  model built  with a combination of HFD and multiple low dose of STZ  injection has the characteristics of high blood glucose, damage of IS function and insulin resistance. In the type 2 diabeic models the protein expressions of 11β-HSD1 and GR are significantly increased.

Key words:  type 2 diabetes mellitus, insulin resistance, 11 -hydroxysteroid dehydrogenase type 1, glucocorticoids;glucocorticoid receptors