Mineralocorticoid receptor is essential for corticosteroid-induced up-regulation of L-type calcium currents in cultured neonatal cardiomyocytes
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Despite the fact that mineralocorticoid receptor (MR) antagonist drugs such as spironolactone and eplerenone reduce the mortality in heart failure patients, there is, thus far, no unambiguous demonstration of a functional role of MR in cardiac cells. The aim of this work was to investigate the activation pathway(s) mediating corticosteroid-induced up-regulation of cardiac calcium current (I Ca). In this study, using neonatal cardiomyocytes from MR or glucocorticoid receptor (GR) knockout (KO) mice, we show that MR is essential for corticosteroid-induced up-regulation of I Ca. This study provides the first direct and unequivocal evidence for MR function in the heart.
KeywordsCorticosteroids Nuclear receptors Aldosterone Calcium current
This study has been funded by the Swiss National Science Foundation PP00-110638/1 (HA) and 3100AO-105592 (DF). We are grateful to Dr. Michael Harris for his helpful suggestions on this manuscript.