The glucocorticoid receptor and the mineralocorticoid receptor are hormone-dependent transcription factors. They regulate the excitability of rat hippocampus CA1 neurons in a coordinated fashion. We studied the spatial distribution of these transcription factors in nuclei of CA1 neurons by dual labeling immunocytochemistry and confocal microscopy, combined with novel image restoration and image...

The mineralocorticoid receptor has been implicated in the development of several cardiac pathologies and could participate in the high incidence of lethal ventricular arrhythmias associated with hyperaldosteronism. We have observed previously that aldosterone markedly increases in vitro the rate of spontaneous contractions of isolated neonate rat ventricular myocytes, a putative proarrhythmogen...

Pseudohypoaldosteronism (PHA) is a rare heterogeneous syndrome of mineralocorticoid resistance causing insufficient potassium and hydrogen secretion. PHA type 1 (PHA1) causes neonatal salt loss, failure to thrive, dehydration and circulatory shock. Two different forms of PHA1 can be distinguished on the clinical and genetic level, showing either a systemic or a renal form of mineralocorticoid r...

Mineralocorticoid receptor (MR) activation may be deleterious to the cardiovascular system, and MR antagonists improve morbidity and mortality of patients with heart failure. However, mineralocorticoid signaling in the heart remains largely unknown. Using a pan-genomic transcriptomic analysis, we identified neutrophil gelatinase-associated lipocalin (NGAL or lipocalin 2) as a strongly induced g...

These studies further evaluated the relative role of mineralocorticoid (type I) and glucocorticoid (type II) receptors in mediating corticosteroid feedback regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Acute treatment of rats with the selective mineralocorticoid receptor antagonist, RU28318 (50 mg/kg sc), produced elevated basal corticosterone levels in the morning, but had no ef...

The aim of this study was to investigate fast corticosteroid feedback of the hypothalamic-pituitary-adrenal (HPA) axis under basal conditions, in particular the role of the mineralocorticoid receptor. Blood samples were collected every 5 min from conscious rats at the diurnal peak, using an automated blood sampling system, and assayed for corticosterone. Feedback inhibition by rapidly increasin...

Apparent mineralocorticoid excess (AME) is a genetic disorder causing severe hypertension, hypokalemia, and hyporeninemic hypoaldosteronism owing to deficient 11 beta-hydroxysteroid dehydrogenase type-2 (11βHSD2) enzyme activity. The 11βHSD2 enzyme confers mineralocorticoid receptor specificity for aldosterone by converting cortisol to its inactive metabolite, cortisone and inactivating the cor...