Dopaminergic regulation of aldosterone secretion: how credible?

It is generally acknowledged that the reninangiotensin system is of prime importance in the hierarchy of factors regulating aldosterone secretion [ 1-41. Potassium and adrenocorticotropin (ACTH) also influence aldosterone secretion [l-41 and sodium may have a direct effect on aldosterone release independent of the reninangiotensin system [2, 5, 61, at least in some species. From time to time it has been suggested that there may be other stimuli for aldosterone secretion [7, 81. Serotonin [2, 9, 101 stimulates aldosterone secretion in vitro. Its physiological role, if any, is unclear. The role of prostaglandins is controversial. New aldosterone-stimulating factors distinct from ACTH or angiotensins have now been reported [l 1, 121. Their precise nature still eludes complete characterization. Some of the members of the ACTH family, such as P lipotropin, a-MSH, P-MSH and T-MSH, also may conceivably be involved in the normal [13-171 or abnormal [18, 191 regulation of aldosterone secretion. All of these factors have been stimulatory in nature, but in 1979 an inhibitory control of aldosterone secretion through a dopaminergic mechanism was suggested [20]. The concept had emerged as a result of a number of observations to be discussed in the succeeding section. The idea of a dopaminergic control over aldosterone secretion is of interest because a physiological role for dopamine in renal sodium excretion has been advocated [21-231. An inhibitory effect of dopamine on aldosterone secretion, if substantiated,