scholarly journals Role of ACTH and Other Hormones in the Regulation of Aldosterone Production in Primary Aldosteronism

2016 ◽  
Vol 7 ◽  
Author(s):  
Nada El Ghorayeb ◽  
Isabelle Bourdeau ◽  
André Lacroix
2019 ◽  
Vol 180 (2) ◽  
pp. R45-R58 ◽  
Author(s):  
Julia Morera ◽  
Yves Reznik

The strategy for diagnosis of primary aldosteronism (PA) in the hypertensive population includes firstly a screening step, based on the measurement of plasma aldosterone-to-renin ratio (ARR), a test which must have high sensitivity, and secondly a confirmatory step based on the demonstration of excessive aldosterone production independent of the renin-angiotensin-aldosterone system (RAAS) activity. The high proportion of false-positive ARR results and conversely of actual PA without a persistent elevation in baseline plasma aldosterone concentration necessitates the addition of a confirmatory step in the work-up of PA diagnosis. The present review focuses on the description of the different dynamic tests available for demonstrating autonomy of aldosterone secretion, on the performance and limitations of confirmatory tests and on possible strategies for PA diagnosis which may either include or avoid the confirmatory step for PA diagnosis. Large prospective studies comparing different strategies with and without dynamic testing are mandatory to delineate clearly the role and limits of confirmatory tests in the work-up of PA.


2002 ◽  
pp. 795-802 ◽  
Author(s):  
F Fallo ◽  
V Pezzi ◽  
L Barzon ◽  
P Mulatero ◽  
F Veglio ◽  
...  

BACKGROUND: The presence and pathophysiological role of CYP11B1 (11beta-hydroxylase) gene in the zona glomerulosa of human adrenal cortex is still controversial. METHODS: In order to specifically quantify CYP11B1, CYP11B2 (aldosterone synthase) and CYP17(17alpha-hydroxylase) mRNA levels, we developed a real-time RT-PCR assay and examined the expression in a series of adrenal tIssues, including six normal adrenals from patients adrenalectomized for renal cancer and twelve aldosterone-producing adenomas (APA) from patients with primary aldosteronism. RESULTS: CYP11B1 mRNA levels were clearly detected in normal adrenals, which comprised both zona glomerulosa and fasciculata/reticularis cells, but were also measured at a lower range (P<0.05) in APA. The levels of CYP11B2 mRNA were lower (P<0.005) in normal adrenals than in APA. CYP17 mRNAlevels were similar in normal adrenals and in APA. In patients with APA, CYP11B2 and CYP11B1 mRNA levels were not correlated either with basal aldosterone or with the change from basal aldosterone in response to posture or to dexamethasone. No correlation between CYP11B1 mRNA or CYP11B2 mRNA and the percentage of zona fasciculata-like cells was observed in APA. CONCLUSIONS: Real-time RT-PCR can be reliably used to quantify CYP11B1 and CYP11B2 mRNA levels in adrenal tIssues. Expression of CYP11B1 in hyperfunctioning zona glomerulosa suggests an additional formation of corticosterone via 11beta-hydroxylase, providing further substrate for aldosterone biosynthesis. CYP11B1 and CYP11B2 mRNA levels in APA are not related to the in vivo secretory activity of glomerulosa cells, where post-transcriptional factors might ultimately regulate aldosterone production.


2012 ◽  
Vol 9 (2) ◽  
pp. 104-112 ◽  
Author(s):  
Paolo Mulatero ◽  
Silvia Monticone ◽  
William E. Rainey ◽  
Franco Veglio ◽  
Tracy Ann Williams

2021 ◽  
Vol 67 (4) ◽  
pp. 203-215
Author(s):  
Jeff S Chueh ◽  
Kang-Yung Peng ◽  
Vin-Cent Wu ◽  
Shuo-Meng Wang ◽  
Chieh-Kai Chan ◽  
...  

Somatic mutation in the KCNJ5 gene is a common driver of autonomous aldosterone overproduction in aldosterone-producing adenomas (APA). KCNJ5 mutations contribute to a loss of potassium selectivity, and an inward Na+ current could be detected in cells transfected with mutated KCNJ5. Among 223 unilateral primary aldosteronism (uPA) individuals with a KCNJ5 mutation, we identified 6 adenomas with a KCNJ5 p.Gly387Arg (G387R) mutation, previously unreported in uPA patients. The six uPA patients harboring mutant KCNJ5-G387R were older, had a longer hypertensive history, and had milder elevated preoperative plasma aldosterone levels than those APA patients with more frequently detected KCNJ5 mutations. CYP11B2 immunohistochemical staining was only positive in three adenomas, while the other three had co-existing multiple aldosterone-producing micronodules. The bioinformatics analysis predicted that function of the KCNJ5-G387R mutant channel could be pathological. However, the electrophysiological experiment demonstrated that transfected G387R mutant cells did not have an aberrantly stimulated ion current, with lower CYP11B2 synthesis and aldosterone production, when compared to that of the more frequently detected mutant KCNJ5-L168R transfected cells. In conclusion, mutant KCNJ5-G387R is not a functional KCNJ5 mutation in unilateral PA. Compared with other KCNJ5 mutations, the observed mildly elevated aldosterone expression actually hindered the clinical identification of clinical unilateral PA. The KCNJ5-G387R mutation needs to be distinguished from functional KCNJ5 mutations during genomic analysis in APA evaluation because of its functional silence.


1994 ◽  
Vol 297 (3) ◽  
pp. 523-528 ◽  
Author(s):  
I Kojima ◽  
N Kawamura ◽  
H Shibata

The present study was conducted to monitor precisely the activity of protein kinase C (PKC) in adrenal glomerulosa cells stimulated by angiotensin II (ANG II). PKC activity in cells was monitored by measuring phosphorylation of a synthetic KRTLRR peptide, a specific substrate for PKC, immediately after the permeabilization of the cells with digitonin [Heasley and Johnson J. Biol. Chem. (1989) 264, 8646-8652]. Addition of 1 nM ANG II induced a gradual increase in KRTLRR peptide phosphorylation, which reached a peak at 30 min, and phosphorylation was sustained thereafter. When the action of ANG II was terminated by adding [Sar1,Ala8]ANG II, a competitive antagonist, both Ca2+ entry and KRTLRR phosphorylation ceased rapidly, whereas diacylglyercol (DAG) content was not changed significantly within 10 min. Similarly, when blockade of Ca2+ entry was achieved by decreasing extracellular Ca2+ to 1 microM or by adding 1 microM nitrendipine, KRTLRR peptide phosphorylation was decreased within 5 min. In addition, restoration of Ca2+ entry was accompanied by an immediate increase in KRTLRR peptide phosphorylation. Under the same condition, DAG content did not change significantly. We then examined the role of the PKC pathway in ANG II-induced aldosterone production. Ro 31-8220 inhibited ANG II-induced KRTLRR phosphorylation without affecting the activity of calmodulin-dependent protein kinase II. In the presence of Ro 31-8220, ANG II-mediated aldosterone production was decreased to approx. 50%. Likewise, intracellular administration of PKC19-36, a sequence corresponding to residues 19-36 of the regulatory domain of PKC known to inhibit PKC activity, attenuated ANG II-mediated activation of PKC and aldosterone output. These results indicate a critical role of Ca2+ entry in the regulation of PKC activity by ANG II.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Ute I Scholl ◽  
Gabriel Stölting ◽  
Carol Nelson-Williams ◽  
Alfred A Vichot ◽  
Murim Choi ◽  
...  

Many Mendelian traits are likely unrecognized owing to absence of traditional segregation patterns in families due to causation by de novo mutations, incomplete penetrance, and/or variable expressivity. Genome-level sequencing can overcome these complications. Extreme childhood phenotypes are promising candidates for new Mendelian traits. One example is early onset hypertension, a rare form of a global cause of morbidity and mortality. We performed exome sequencing of 40 unrelated subjects with hypertension due to primary aldosteronism by age 10. Five subjects (12.5%) shared the identical, previously unidentified, heterozygous CACNA1HM1549V mutation. Two mutations were demonstrated to be de novo events, and all mutations occurred independently. CACNA1H encodes a voltage-gated calcium channel (CaV3.2) expressed in adrenal glomerulosa. CACNA1HM1549V showed drastically impaired channel inactivation and activation at more hyperpolarized potentials, producing increased intracellular Ca2+, the signal for aldosterone production. This mutation explains disease pathogenesis and provides new insight into mechanisms mediating aldosterone production and hypertension.


2015 ◽  
Vol 33 (5) ◽  
pp. 1014-1022 ◽  
Author(s):  
Chiara Recarti ◽  
Teresa Maria Seccia ◽  
Brasilina Caroccia ◽  
Abril Gonzales-Campos ◽  
Giulio Ceolotto ◽  
...  

2017 ◽  
Vol 49 (12) ◽  
pp. 963-968 ◽  
Author(s):  
Ute Scholl

AbstractOver the past six years, the genetic basis of a significant fraction of primary aldosteronism (PA) cases has been solved. Breakthrough discoveries include the role of somatic variants in the KCNJ5, CACNA1D, ATP1A1, and ATP2B3 genes as causes of aldosterone-producing adenomas (APAs), and the recognition of three novel hyperaldosteronism syndromes with germline variants in the KCNJ5, CACNA1D, and CACNA1H genes. The description of somatic variants in CACNA1D and ATP1A1 in aldosterone-producing cell clusters (APCCs) suggests that these clusters are precursors of some aldosterone-producing adenomas. Yet, a number of questions remain unanswered. These include the genetic basis of about 40% of APAs without somatic variants in known genes. Do technical issues explain this finding, or are the unexplained APAs due to somatic copy number variation or rare variants in thus-far undiscovered genes? Similarly, the role of CTNNB1 (beta catenin) variants in APA pathogenesis is still unclear. The major question to be solved is the genetic basis of bilateral adrenal hyperplasia (BAH). Is BAH due to the bilateral occurrence of APCCs, to germline variants, or perhaps due to unknown serum factors? Lastly, the etiology of unsolved cases of apparently familial hyperaldosteronism remains to be discovered. It is expected that genetic studies over the next few years will lead to answers to at least some of the questions raised.


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