Cellular mechanisms of action of mineralocorticoid hormones.

Mineralocorticoid hormones are a subset of steroid hormones that act primarily in epithelial tissues to regulate ion transport of Na+, K+ and H+. Cellular specificity is conferred by receptors which act in the nucleus to stimulate gene expression. Transcription and subsequent translation result in the production of new proteins which mediate the physiologic effects. The mechanisms involved in receptor specificity and localization, in regulation of gene activation, and in expression of transport effects are reviewed. The cellular actions of mineralocorticoids fit well with the general model of steroid hormone action but considerable questions remain at each step in the process.