Classic versus non-classic receptors for nongenomic mineralocorticoid responses: emerging evidence.

Mineralocorticoids, which are synthesized locally in the central nervous system in addition to their adrenal production, trigger both genomic and nongenomic responses. Several functions of mineralocorticoids in the CNS are known to date, which are reviewed along with nongenomic responses in other tissues. A controversy regarding the identity of receptors that mediate nongenomic, transcription-independent cellular responses to steroids is presently attracting considerable scientific interest. While there is strong evidence for classic receptors belonging to the nuclear receptor superfamily to mediate nongenomic steroid effects in some cases, it does not exist for others. Recent findings on new and unexpected properties of classic receptors have partially withdrawn the interest from novel, non-classic membrane receptors, which are being progressively identified at present. This has been facilitated by the robust and elaborate toolkit for classic receptor studies in contrast to the comparably immature research tools for alternative receptors. To know the nature of receptors involved may be the key to beneficial medical translation of specific and targeted steroid responses.