The story of spironolactones from 1957 to now: from sodium balance to inflammation.

After the discovery of aldosterone (1953), many synthetic steroids were tested for their ability to block the sodium retaining and potassium excreting effect of synthetic mineralocorticoids in adrenalectomized rats. In the same years Kagawa discovered that 17-spirolactone steroids were effective to block mineralocorticoid effects, but when used alone they did not produce any effect in adrenalectomized rats. After the description of the first case of primary aldosteronism (1955), spironolactone (SP) was considered the main treatment before surgery to control blood pressure and kaliemia and for long-term treatment in patients with bilateral adrenal hyperplasia. SP was further used for various clinical situations, such as liver cirrhosis, idiopathic oedema, nephrosis and congestive heart failure. SP also shows an antiandrogen action, effective in polycystic ovary syndrome. In 1985 we demonstrated that human mononuclear leukocytes (MNL) possess mineralocorticoid receptors (MR) and lately we demonstrated that coincubation of MNL with canrenone blocked aldosterone mediated inflammatory, reducing the expression of PAI-1 and p22phox. It is well known that MNL and macrophages are mainly involved in vascular inflammation and atherosclerosis and we have hypothesized that the tissue invasion of MNL brings MR in the site of inflammation starting the process. Recently, aldosterone has been associated with the promotion of many organ-specific autoimmune diseases, inducing Th17 polarization of CD4+ T cells and suggesting new possible therapeutic targets for anti-mineralocorticoid drugs. In conclusion, considering all the benefits of MR-antagonists, their use should be reconsidered not only for the treatment but also for the prevention of many clinical situations.

The discovery, isolation and identification of aldosterone: reflections on emerging regulation and function.

This paper has a focus on the early history of aldosterone. The Taits take us on a chronological trawl through the history in which they had a first hand role and made a major contribution-their bioassay was in many ways the key. The gifted Swiss chemists made a critical contribution to the scale and isolation of larger amounts. This was international collaboration at its best. Developing technologies were utilised as crucial cutting edge applications in the advancing front, technology transfer before the word was invented. Measurement of aldosterone and angiotensin were crucial advances to the understanding of the regulation of the hormone. In the period 1960-2003, some 30,000 papers mentioned aldosterone as a keyword, even so advances on a larger scale were slow. I have indicated some of my own work with the Howard Florey team using the adrenal autotransplant in the conscious sheep. Recently, the understanding of the role of induced proteins, the flow on from the RALES trial and the development of eplerenone has revitalised the aldosterone field.

The evolution of aldosterone antagonists.

Since the isolation and purification of aldosterone from adrenal extracts 50 years ago (Experientia 9 (1953) 33), scientists have learned a great deal about how and where aldosterone acts, the factors that control its release, what is its role in the pathophysiology of cardiovascular disease, how to make and study aldosterone antagonists, and for what medical purposes these agents are useful. In this paper, we will discuss the evolution of aldosterone antagonists from the relatively nonselective spironolactone (Aldactone), to the highly selective eplerenone (Inspra). Eplerenone represents a molecule with improved steroid receptor selectivity and pharmacokinetic properties in man compared to spironolactone. Recent clinical results have demonstrated that these improvements translate into tolerability and efficacy in patients with cardiovascular disease.

The 45-year story of the development of an anti-aldosterone more specific than spironolactone.

At the early stage of its development in 1957, the daily dose of spironolactone necessary to improve various pathological conditions was not precisely determined and dose-dependent sexual side effects limited its long-term use. Prescription of high daily doses and absence of selectivity for the mineralocorticoid receptor explain these limitations. The 9-11alpha epoxy group added to mexrenone by the Ciba-Geigy chemists in 1984 and improved chemical synthesis at Searle, permitted the original international clinical development of a selective antagonist for high blood pressure and congestive heart failure treatment. This review deals with the main methodological issues of a 20-year biological and clinical development of eplerenone, the second antimineralocorticoid drug. The investigation of a large range of daily doses (25-400mg) initially selected in normal volunteers by the 9alpha-fluorohydrocortisone test has led to the conclusion that 50-100mg q.i.d. doses of eplerenone offer a favorable benefit/risk ratio in various patient populations by neutralization of the aldosterone effects on blood pressure and target organ damage. The absence of sexual side-effects has confirmed the clinical relevance of the initial biological hypothesis on the need for more selectivity at the androgen and progestogen receptor sites. Widening the distance between efficacy and adverse effects of an anti-mineralocorticoid drug will facilitate the long-term maintenance of a moderately negative sodium balance and a slightly positive potassium balance, while minimizing the direct effects of salt and aldosterone on the heart, vessels, brain, and kidneys. Wide use in unselected patients and additional controlled clinical trials are necessary to confirm the benefits expected from animal and clinical research given that a 45-year interval also characterizes the story of the Na-Cl cotransporter (NCC) blocker, chlorthalidone, from its initial clinical use to the demonstration of its beneficial effects on cardiovascular morbidity and mortality.