The mineralocorticoid receptor in endothelial physiology and disease: novel concepts in the understanding of erectile dysfunction

Abstract

Aldosterone is a steroid hormone that controls blood pressure by binding to the mineralocorticoid receptor (MR), a ligand-activated transcription factor, and regulating genes that play a role in salt and water homeostasis in the kidney. Dysregulation of the mineralocorticoid system reveals its crucial role in various human diseases including hypertension, atherosclerosis, cardiac failure, mineralocorticoid resistance, and disorders of the nervous system. Recently, experimental animal models of mineralocorticoid/salt-induced hypertension and atherosclerosis have revealed an epithelial, pro-inflammatory role for MR activation. Extensive investigation has begun to elucidate the mechanisms underlying the vascular effects of MR activation which involve its direct role in cardiomyocytes, vascular smooth muscle cells, and endothelial cells. More specifically, in patients with cardiovascular risk factors and disease, including diabetes, hypertension, and/or congestive heart failure, an excess of MR activation has been shown to have a negative impact on endothelial function hence disrupting the physiological balance between vasoconstriction and vasodilation. Such a mechanism may play a role in the pathogenesis of erectile dysfunction (ED), a condition that occurs frequently in patients with increased cardiovascular risk and involves endothelial dysregulation of vascular relaxation. The aim of this review is to summarize the latest concepts in MR signaling, with particular attention to the endothelium, and to discuss the potential benefits of tissue-selective MR blockade in treating subsets of ED patients, such as those with congestive heart failure and hypertension, in which the MR system may be over activated.