Regulation of growth hormone messenger RNA.

In cultured rat pituitary cells, glucocorticoids regulate growth hormone production by modulating the number of growth hormone messenger RNA molecules. The effect is quite specific, since only a few other mRNAs are affected by the hormones. This response is demonstrated by assays involving cell-free mRNA translation and cDNA-RNA hybridization. Furthermore, the inducibility by the glucocorticoids is regulated by at least one other class of hormones, thyroid hormone. Thus, this system serves as a model for studying not only the glucocorticoid regulation of specific mRNA, but also the control of this regulation by other factors in the target tissue.