Alteration of glucocorticoid receptor subcellular distribution by hyperthermic stress

The aim of the present study was to examine intracellular redistribution of the glucocorticoid receptor (GR) in rat liver cells during a 24-h time period after exposure of the animals to 41°C whole body hyperthermic stress. The level of the receptor protein in the cytoplasmic and nuclear compartments was measured by immunoblotting procedures applied to both crude cytosol and immunopurified GR, as well as by immunocytochemical analyses applied to both paraffin-embedded liver sections and unfixed nuclear smears. All the experimental approaches employed in the study provided similar results, demonstrating that the transient stress-related decline of the cytoplasmic GR observed during the first five hours after exposure of the animals to whole-body hyperthermic stress is accompanied by enhanced nuclear accumulation of the receptor. The study can contribute to a better understanding of the influence of stress on the glucocorticoid signal transduction pathway.