Two Receptor Systems for Corticosterone in Rat Brain: Microdistribution and Differential Occupation

作者：Johannes M. H. M. Reul, E. R. de Kloet · 发表于：Endocrinology · 年份：1985 · DOI：10.1210/endo-117-6-2505 · 被引用次数：2589 · 研究领域：Stress Responses and Cortisol、Hormonal and reproductive studies、Hormonal Regulation and Hypertension

Two receptor systems for corticosterone (CORT) can be distinguished in rat brain: mineralocorticoid-like or CORT receptors (CR) and glucocorticoid receptors (GR). The microdistribution and extent of occupation of each receptor population by CORT were studied. The CR system is restricted predominantly to the lateral septum and hippocampus. Within the hippocampus, the highest density occurs in the subiculum +/- CA1 cell field (144 fmol/mg protein) and the dentate gyrus (104 fmol/mg protein). Affinity of CR for CORT was very high (Kd, approximately 0.5 nM). The GR system has a more widespread distribution in the brain. The highest density for GR is in the lateral septum (195 fmol/mg protein), the dentate gyrus (133 fmol/mg protein), the nucleus tractus solitarii and central amygdala. Substantial amounts of GR are present in the paraventricular nucleus and locus coeruleus and low amounts in the raphe area and the subiculum + CA1 cell field. The affinity of GR for CORT (Kd, approximately 2.5-5 nM) was 6- to 10-fold lower than that of CR. Occupation of CR by endogenous ligand was 89.5% during morning trough levels of pituitary-adrenal activity (plasma CORT, 1.4 micrograms/100 ml). Similar levels of occupation (88.7% and 97.6%) were observed at the diurnal peak (plasma CORT, 27 micrograms/100 ml) and after 1 h of restraint stress (plasma CORT, 25 micrograms/100 ml), respectively. Furthermore, a dose of 1 microgram CORT/100 g BW, sc, resulted in 80% CORT receptor occupation, whereas ...