Chronic Effects of Aldosterone on Cardiac EC Coupling and Oxidant Stress

Abstract

Our previous work investigated the role of aldosterone in the function of atrial myocytes. Among other effects, aldosterone promoted a striking 2-fold increase in the density of Ca 2þ current (I Ca ) and a moderated increase of 30% in cell membrane capacitance (C m , suggesting hypertrophy). Ca 2þ and ROS were identified to participate but only on the effect on C m . The objective of this work was twofold: (a) to determine whether aldosterone regulates ROS generation; and (b) to reexamine the potential of aldosterone to increase I Ca , using a low Ca 2þ buffering internal solutionthis allows recording Ca 2þ transients as well. Adult rat cardiomyocytes were chronically incubated with 1 mM aldosterone. Subsequently, I Ca and Ca 2þ transients were recorded under whole-cell patch clamp. CM-H 2 CDFDA was used to monitor ROS. Under the present conditions, aldosterone did not alter the peak amplitude of I Ca . However, it promoted 478-PosQuantitative In Silico