Regulation of insulin-receptor mRNA levels by glucocorticoids.

We found with IM-9 human cultured lymphocytes, that the glucocorticoid dexamethasone increased insulin-receptor mRNA levels. This increase correlated in a time- and dose-dependent manner with the increase in the biosynthesis of the insulin-receptor precursor. In addition, in AR42J cultured rat pancreatic acinar cells, dexamethasone increased insulin-receptor mRNA levels. These studies suggest, therefore, that an increase in mRNA levels is an early step in the regulation of the insulin receptor by glucocorticoids in several cell types.