Glucocorticoid receptor gene expression in the embryonic rat brain.

The early ontogenetic pattern of glucocorticoid receptor (GR) gene expression was studied in the rat brain through embryonic days (E) 12 to 17. Using a [35S]-labelled GR antisense RNA probe for in situ hybridization, we first detected GR mRNA in E13 embryos. The strongest signal was in Rathke's pouch, but the hypothalamic, and to a lesser degree the pontine and rhinencephalic neuroepithelium were also moderately labelled.

Import of the glucocorticoid receptor into rat liver mitochondria in vivo and in vitro.

Administration of inducing doses of dexamethasone (10 microg/100 g) to adrenalectomized rats results, within 2-5 min, in import of the glucocorticoid receptor from liver cytoplasm into mitochondria, as demonstrated by Western blotting and by electron microscopy. Furthermore, glucocorticoid receptor (GR) synthesized in an in vitro reticulocyte system programmed with the respective mRNA, enters within minutes to added rat liver mitochondria in the form of intact GR, as demonstrated by Western blotting using either monoclonal or polyclonal antibodies against different domains of GR. In vitro studies show that the import is dependent on temperature and/or activation of the hormone-GR complex.