The mineralocorticoid receptor (MR) responds not only to the physiological mineralocorticoids, aldosterone and deoxycorticosterone, but also to the physiological glucocorticoid, cortisol. The MR is a member of the nuclear receptor superfamily that acts as a ligand-dependent transcription factor. The structural determinants of MR function are described and discussed. The MR mediates its effects not only through a transcriptional mechanism but also through nongenomic mechanisms and perhaps through transrepression. The nature of these responses is both ligand and tissue dependent. The MR is expressed in a number of tissues beyond the traditional epithelial targets for aldosterone, including the central nervous and the cardiovascular systems.
