Endocrinology, Vol 129, 3064-3072, Copyright © 1991 by Endocrine Society
Immunocytochemical localization of the glucocorticoid receptor in rat brain, pituitary, liver, and thymus with two new polyclonal antipeptide antibodies
WC McGimsey, JA Cidlowski, WE Stumpf and M Sar
Department of Cell Biology, University of North Carolina, Chapel Hill 27599.
The intracellular localization of the glucocorticoid receptor (GR) was
studied in male rat brain, pituitary, liver, and thymus. Two new polyclonal
anti-GR antibodies, GR 57 and GR 59, raised against two synthetic peptides
(346-357 and 245-259) that correspond to unique regions of the
amino-terminus of human GR were used. Vibratome sections (30-50 microns) of
perfused brain and frozen sections (6-8 microns) of pituitary, liver, and
thymus fixed in paraformaldehyde were incubated in preimmune serum,
immunoserum, epitope-purified immunoserum, or peptide-absorbed immunoserum
of either GR 57 or GR 59 and immunostained by the avidin-biotin peroxidase
method. GR immunoreactivity (GR-ir) was primarily nuclear in brain,
pituitary, liver, and thymus sections from intact rats. Adrenalectomy
caused nuclear GR-ir to decrease and cytoplasmic GR-ir to increase. When
adrenalectomized rats were treated with corticosterone (100 micrograms and
1 mg) or dexamethasone (1 microgram, 100 micrograms, and 1 mg), GR-ir was
again predominantly nuclear. One microgram of corticosterone failed to
cause nuclear GR-ir when administered to adrenalectomized rats.
Immunoreactive neurons and glial cells were extensively distributed, with
varied intensity, throughout the rat forebrain. The areas include cortex,
septum, hippocampus, amygdala, thalamus, and hypothalamus. Cells with the
strongest GR-ir were located in the caudate putamen, paraventricular,
arcuate, and central amygdala nuclei, areas CA1-CA2 of the hippocampus, and
laminae 4 and 5 of the cortex. In the pituitary, cells of the anterior and
posterior lobes were GR immunoreactive, while those in the intermediate
lobe were not. Hepatocytes of the liver and thymocytes and
reticuloepithelial cells of the thymus were GR immunoreactive. The results
show that GR can be localized immunocytochemically in numerous rat tissues
using antipeptide polyclonal antibodies and correlated with the results of
biochemical and ligand receptor studies.
