Interaction of rapid nongenomic cardiovascular aldosterone effects with the adrenergic system.

Interactions between the renin-angiotensin-aldosterone system and the adrenergic system are complex and have mainly been attributed to angiotensin II, with knowledge about aldosterone action much less advanced. Only recently has evidence been forthcoming that aldosterone blunts the baroreceptor reflex and lowers heart rate variability in humans. Both effects point to an adrenergic-like action of aldosterone. It has been proposed that this blunting of baroreceptor sensitivity is mediated nongenomically and that nongenomic aldosterone action itself is modulated by the adrenergic system. The aim of the present study was to prove the hypothesis of an interaction between the autonomic nervous system and rapid, nongenomic aldosterone effects. We conducted a randomized, double blind, 8-fold cross-over trial on 18 healthy male volunteers. After pretreatment with the β-blocking agent esmolol, the β-agonist dobutamine, the α1-agonist phenylephrine, or placebo, placebo (0.9% NaCl) or aldosterone (0.5 mg) was injecte...