Abstract:

Objective    To investigate the effects of aldosterone  on the expression of phosphoserine 473-Akt and PTEN in normal or insulin resistant adipocytes，  with the aim to explore the role of  aldosterone in the pathogenesis of insulin resistance. Methods    Insulin resistant 3T3-L1 adipocytes were induced by dexamethasone and insulin. The protein expressions of  PTEN and phosphoserine 473-AKT in normal and insulin resistant adipocytes treated with aldosterone or  spironolactone were measured by Western blot. Results    Compared with normal adipocytes, expression of PTEN protein increased（0.83±0.11）vs（0.63±0.06）, P＜0.05］ and phosphoserine 473-AKT protein  decreased（0.52±0.12）vs（0.78±0.12）, P＜0.05］ in insulin resistant models. Aldosterone-induced upregulation of PTEN and degradation of phosphoserine 473AKT was markedly attenuated by spironolactone,  a mineralocorticoid receptor antagonist（all P＜0.05). Conclusion    Aldosterone induces insulin resistance possibly via the PI3K-Akt pathway in 3T3-L1 adipocytes.

Key words: Aldosterone; Spironolactone; phosphatase and tensin homologue deleted on chromosome 10; Phosphatidylinositol 3-kinase-Akt; Insulin resistance