Non-interaction of spironolactone medication and cortisol metabolism in man

Abiraterone and spironolactone in prostate cancer: a combination to avoid

Objectives: Disease progression in metastatic castration-resistant prostate cancer (mCRPC) is dependent on androgen signaling. This case describes the complex adaptive androgen signaling mechanisms in mCRPC and illustrates that caution should be exercised when treating these patients with drugs influencing the androgen axis.Methods: Single case report and review of the literature.Results: We report the case of an 86-year-old man with mCRPC, treated with the secondary antihormonal agent abiraterone acetate. Following association of spironolactone to deal with symptoms related to mineralocorticoid excess, biochemical and radiographic disease progression occurred. Spironolactone was discontinued and 8 months after withdrawal, the patient continues to show a biochemical response to abiraterone.Conclusions: Although spironolactone generally exerts anti-androgenic effects, experimental evidence exists that it acts as an androgen receptor agonist in an androgen-depleted environment, capable of inducing prostate cancer proliferation. This is supported by the observations described in this case report. Therefore, spironolactone should be avoided in prostate cancer patients suffering from treatment-associated side effects of abiraterone.

Displacement of cortisol from human heart by acute administration of a mineralocorticoid receptor antagonist

CONTEXT

Mineralocorticoid receptor (MR) antagonists have beneficial effects in patients with heart failure and myocardial infarction, often attributed to blocking aldosterone action in the myocardium. However, binding of aldosterone to MR requires local activity of the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which inactivates cortisol to cortisone and thereby prevents receptor occupancy by cortisol. In vivo activity of 11β-HSD2 and potential occupancy of MR by cortisol in human heart have not been quantified.

OBJECTIVE

This study aimed to measure in vivo activity of 11β-HSD2 and to establish whether cortisol binds MR in human heart.

PARTICIPANTS AND INTERVENTIONS

Nine patients without heart failure undergoing diagnostic coronary angiography were infused to steady state with the stable isotope tracers 9,11,12,12-[(2)H]4-cortisol and 1,2-[(2)H]2-cortisone to quantify cortisol and cortisone production. Samples were obtained from the femoral artery and coronary sinus before and for 40 minutes after bolus iv administration of an MR antagonist, potassium canrenoate. Coronary sinus blood flow was measured by venography and Doppler flow wire.

RESULTS

There was no detectable production of cortisol or cortisone across the myocardium. After potassium canrenoate administration, plasma aldosterone concentrations increased substantially but aldosterone was not detectably released from the myocardium. In contrast, plasma cortisol concentrations did not change in the systemic circulation but tissue-bound cortisol was released transiently from the myocardium after potassium canrenoate administration.

CONCLUSIONS

Human cardiac 11β-HSD2 activity appears too low to inactivate cortisol to cortisone. Cortisol is displaced acutely from the myocardium by MR antagonists and may contribute to adverse MR activation in human heart.

Corticosteroids mediate fast feedback of the rat hypothalamic-pituitary-adrenal axis via the mineralocorticoid receptor

The aim of this study was to investigate fast corticosteroid feedback of the hypothalamic-pituitary-adrenal (HPA) axis under basal conditions, in particular the role of the mineralocorticoid receptor. Blood samples were collected every 5 min from conscious rats at the diurnal peak, using an automated blood sampling system, and assayed for corticosterone. Feedback inhibition by rapidly increasing concentrations of ligand was achieved with an intravenous bolus of exogenous corticosteroid. This resulted in a significant reduction in plasma corticosterone concentrations within 23 min of the aldosterone bolus and 28 min of methylprednisolone. Evaluation of the pulsatile secretion of corticosterone revealed that the secretory event in progress at the time of administration of exogenous steroid was unaffected, whereas the next secretory event was inhibited by both aldosterone and methylprednisolone. The inhibitory effect of aldosterone was limited in duration (1 secretory event only), whereas that of methylprednisolone persisted for 4-5 h. Intravenous administration of canrenoate (a mineralocorticoid receptor antagonist) also had rapid effects on the HPA axis, with an elevation of ACTH within 10 min and corticosterone within 20 min. The inhibitory effect of aldosterone was unaffected by pretreatment with the glucocorticoid receptor antagonist RU-38486 but blocked by the canrenoate. These data imply an important role for the mineralocorticoid receptor in fast feedback of basal HPA activity and suggest that mineralocorticoids can dynamically regulate basal corticosterone concentrations during the diurnal peak, a time of day when there is already a high level of occupancy of the cytoplasmic mineralocorticoid receptor.

Sleep endocrine effects of antigluco- and antimineralocorticoids in healthy males

In several mammalian species the responsiveness of brain neurons to corticosteroids is mediated by mineralo- (MR) and glucocorticoid (GR) receptors. These receptors play a key role not only in the endocrine adaptation to stress but also in corticosteroid-induced changes of behavior, including sleep. We further explored the specific physiological role of this binary receptor system in the human brain by studying electroencephalogram (EEG) sleep and changes in plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, and growth hormone from 1800 to 0700 h in a series of investigations in healthy men pretreated the previous evening with the nonselective GR agonist dexamethasone (Dex) and then receiving at 1400 h either placebo, spironolactone (Spi), an MR antagonist, or mifepristone (Mif), a GR antagonist. The Dex-induced suppression of ACTH and cortisol was unaltered after Spi (200 mg) but attenuated by Mif treatment (400 mg). The sleep-associated plasma growth hormone surge was increased by Dex, an effect that remained unchanged by Spi but was reduced by Mif treatment. Pretreatment with Dex did not by itself induce recognizable effects on EEG sleep, but the Dex combination with Spi reduced the amount of rapid-eye-movement (REM) sleep. With Dex plus Mif, both REM sleep and slow wave sleep (SWS) were reduced compared with placebo. The Dex-induced endocrine effects on plasma ACTH, cortisol, and growth hormone concentrations could not be antagonized by Spi, which acts via MRs mainly located in the hippocampus, but were compensated for in part by Mif, which antagonizes GR at the pituitary and in the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)