The effects of insulin on hepatic glucocorticoid receptor content in the diabetic rat.

Streptozotocin-induced diabetic rat liver was analyzed for glucocorticoid receptor (GR) content by saturation and Scatchard analysis. The hepatic GR content of streptozotocin-induced diabetic rats was significantly decreased from a control level of 0.17 +/- .01 pmol/mg protein to 0.11 +/- .01 pmol/mg protein. Insulin replacement therapy to the diabetic rat dramatically increased the hepatic GR content to 0.26 +/- 0.02 pmol/mg protein as compared to the diabetic value of 0.11 +/- 0.01 pmol/mg protein. A time course study of GR content in the diabetic rat liver demonstrated that after an initial decrease in hepatic GR content at 14 days, the 25-day diabetic receptor level elevated back to control levels. A significant increase in GR content over controls was observed in the 110-day diabetic rats. These results suggest that insulin has a role in the regulation of hepatic GR content.