Sex steroids enhance insulin receptors and glucose oxidation in Chang liver cells.

BACKGROUND

The present study was designed to assess the effect of sex steroids (testosterone and 17beta-estradiol) on insulin receptor expression, insulin binding and glucose oxidation in human liver cell line.

METHODS

Non-malignant Chang liver cells were treated with different concentrations of testosterone and 17beta-estradiol dissolved in serum free medium for 24 h to identify the effective dose of both steroids for further studies. Cells with 70-80% confluency were challenged with testosterone (0.1 micromol/l), 17beta-estradiol (0.1 micromol/l) and their combination along with insulin as a positive control for 24 h. After the treatment period, insulin receptor mRNA expression, cell surface insulin binding and (14)C-glucose oxidation were assessed.

RESULTS

Both testosterone and 17beta-estradiol significantly increased the insulin receptor mRNA expression, cell surface insulin binding and (14)C-glucose oxidation compared to basal, but the increase was not at par with the effect of insulin. Compared to individual effects of testosterone and 17beta-estradiol, their combination significantly increased the glucose oxidation similar to that of insulin.

CONCLUSION

It is concluded from the present study that testosterone and 17beta-estradiol can directly enhance insulin receptor mRNA expression, insulin binding and glucose oxidation in Chang liver cells and thereby glucose metabolism.