Targeting activated mineralocorticoid receptor: Occam's razor revisited.

Activation of mineralocorticoid receptors (MRs) classically has been associated with electrolyte transport, but we now know that MR activation can also lead to tissue inflammation and fibrosis. Aldosterone consistently activates MR, but under selected circumstances, endogenous glucocorticoids such as cortisol and corticosterone can also trigger MR. Tissue-specific safeguards such as the enzyme 11β-hydroxysteroid dehydrogenase limit glucocorticoid-induced MR activation, while the presence of reactive oxygen species may enhance the ability for glucocorticoid-induced MR activation even in the absence of aldosterone.