Mechanisms Underlying Rapid Aldosterone Effects in the Kidney

The steroid hormone aldosterone is a key regulator of electrolyte transport in the kidney, and contributes to both homeostatic whole body electrolyte balance and also to the development of renal and cardiovascular pathologies. Aldosterone exerts its action principally through the mineralocorticoid receptor (MR), which acts as a ligand-dependent transcription factor in target tissues. Aldosterone also stimulates the activation of protein kinases and secondary messenger signaling cascades that act independently on specific molecular targets in the cell membrane and also modulate the transcriptional action of aldosterone through MR. This review describes current knowledge regarding the mechanisms and targets of rapid aldosterone action in the nephron, and how these responses are integrated into the regulation of renal physiology by aldosterone.