A Gene-Based Classification of Primary Adrenocortical Hyperplasias

Primary or adrenocorticotropin-independent adrenocortical tumors and hyperplasias represent a heterogeneous group of adrenocortical neoplasms that arise from various genetic defects, either in isolation or familial. The traditional classification as adenomas, hyperplasias, and carcinomas is non-specific. The recent identification of various germline and somatic genes in the development of primary adrenocortical hyperplasias has provided important new insights into the molecular pathogenesis of adrenal diseases. In this new era of personalized care and genetics, a gene-based classification that is more specific is required to assist in the understanding of their disease processes, hormonal functionality and signaling pathways. Additionally, a gene-based classification carries implications for treatment, genetic counseling and screening of asymptomatic family members. In this review, we discuss the genetics of benign adrenocorticotropin-independent adrenocortical hyperplasias, and propose a new gene-based classification system and diagnostic algorithm that may aid the clinician in prioritizing genetic testing, screening and counseling of affected, at risk individuals and their relatives.

Long-Term Outcome of Primary Bilateral Macronodular Adrenocortical Hyperplasia After Unilateral Adrenalectomy

CONTEXT

Unilateral adrenalectomy has been proposed in selected patients with primary bilateral macronodular adrenocortical hyperplasia (PBMAH), but its long-term outcome is unclear.

OBJECTIVE

The aim of this study was to analyze long-term clinical and biochemical outcomes of unilateral adrenalectomy vs bilateral adrenalectomy in patients with PBMAH in comparison with the outcome of cortisol-producing adenoma (CPA) treated with unilateral adrenalectomy.

DESIGN

Retrospective observational study in three German and one Italian academic tertiary care center.

PATIENTS AND METHODS

Twenty-five patients with PBMAH after unilateral adrenalectomy (unilat-ADX-PBMAH), nine patients with PBMAH and bilateral adrenalectomy (bilat-ADX-PBMAH), and 39 patients with CPA and unilateral adrenalectomy (unilat-ADX-CPA) were included.

RESULTS

Baseline clinical and biochemical parameters were comparable in patients with unilat-ADX-PBMAH, bilat-ADX-PBMAH, and unilat-ADX-CPA. Directly after surgery, 84% of the patients with unilat-ADX-PBMAH experienced initial remission of Cushing syndrome (CS). In contrast, at last follow-up (median, 50 months), 32% of the patients with unilat-ADX-PBMAH were biochemically controlled compared with nearly all patients in the other two groups (P = 0.000). Adrenalectomy of the contralateral side had to be performed in 12% of the initial patients with unilat-ADX-PBMAH. Three of 20 patients with unilat-ADX-PBMAH (15%) died during follow-up, presumably of CS-related causes; no deaths occurred in the other two groups (P = 0.008). Deaths occurred exclusively in patients who were not biochemically controlled after unilateral ADX.

CONCLUSIONS

Our data suggest that unilateral adrenalectomy of patients with PBMAH leads to clinical remission and a lower incidence of adrenal crisis but in less sufficient biochemical control of hypercortisolism, potentially leading to higher mortality.

Acute adrenal cortex injury during cardiopulmonary bypass in a canine model

OBJECTIVE

Cardiopulmonary bypass (CPB) might induce systemic inflammatory responses that cause acute injuries to multiple organs. However, no direct evidence exists to determine whether CPB leads to adrenal cortex injury or to describe its underlying mechanism.

METHODS

Twelve healthy adult beagles were randomly assigned into control and CPB groups. After cannulation, mild hypothermia CPB was performed in the CPB group but not in the control group. The serum concentrations of various cytokines, cortisol, and aldosterone were assessed. Adrenal cortex injuries were evaluated using standard histological methods. Steroidogenic enzymes and the nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome pathway were detected using quantitative polymerase chain reaction and Western blot analysis.

RESULTS

During CPB, serum interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor α, cortisol, and aldosterone levels were significantly higher in the CPB group. The pathologic study revealed higher injury scores (3.6 ± 0.6 vs 0.7 ± 0.7) and significantly more severe edema, inflammatory cell infiltration (lymphocytes and neutrophils), and apoptosis in the CPB group. The electron microscopic examination showed swollen mitochondria, ruptured mitochondrial cristae, reduced lipid droplets, and increased secondary lysosomes in the CPB group. The mRNA expression levels of NLRP3 and the protein levels of 17α-hydroxylase and IL-1β in adrenal tissue were significantly upregulated in the CPB group.

CONCLUSIONS

CPB induces significant systemic and local inflammation in the adrenal cortex and results in cytological architectural and ultrastructural alterations in adrenocorticocytes. In addition, the NLRP3 inflammasome pathway might promote adrenal gland injury during CPB and might represent a novel potential therapeutic target.

Does somatostatin have a role in the regulation of cortisol secretion in primary pigmented nodular adrenocortical disease (ppnad)? a clinical and in vitro investigation

CONTEXT

Somatostatin (SST) receptors (SSTRs) are expressed in a number of tissues, including the adrenal cortex, but their role in cortisol secretion has not been well characterized.

OBJECTIVES

The objective of the study was to investigate the expression of SSTRs in the adrenal cortex and cultured adrenocortical cells from primary pigmented nodular adrenocortical disease (PPNAD) tissues and to test the effect of a single injection of 100 μg of the SST analog octreotide on cortisol secretion in patients with PPNAD.

SETTING AND DESIGN

The study was conducted at an academic research laboratory and clinical research center. Expression of SSTRs was examined in 26 PPNAD tissues and the immortalized PPNAD cell line CAR47. Ten subjects with PPNAD underwent a randomized, single-blind, crossover study of their cortisol secretion every 30 minutes over 12 hours (6:00 pm to 6:00 am) before and after the midnight administration of octreotide 100 μg sc.

METHODS

SSTRs expression was investigated by quantitative PCR and immunohistochemistry. The CAR47 and primary cell lines were studied in vitro. The data of the 10 patients were analyzed before and after the administration of octreotide.

RESULTS

All SSTRs, especially SSTR1-3, were expressed in PPNAD at significantly higher levels than in normal adrenal. SST was found to differentially regulate expression of its own receptors in the CAR47 cell line. However, the administration of octreotide to patients with PPNAD did not significantly affect cortisol secretion.

CONCLUSIONS

SSTRs are overexpressed in PPNAD tissues in comparison with normal adrenal cortex. Octreotide did not exert any significant effect on cortisol secretion in a short clinical pilot study in a small number of patients with PPNAD, but long-acting SST analogs targeting multiple SSTRs may be worth investigating in this condition.

Systematic screening for PRKAR1A gene rearrangement in Carney complex: identification and functional characterization of a new in-frame deletion

BACKGROUND

Point mutations of the PRKAR1A gene are a genetic cause of Carney complex (CNC) and primary pigmented nodular adrenocortical disease (PPNAD), but in 30% of the patients no mutation is detected.

OBJECTIVE

Set up a routine-based technique for systematic detection of large deletions or duplications of this gene and functionally characterize these mutations.

METHODS

Multiplex ligation-dependent probe amplification (MLPA) of the 12 exons of the PRKAR1A gene was validated and used to detect large rearrangements in 13 typical CNC and 39 confirmed or putative PPNAD without any mutations of the gene. An in-frame deletion was characterized by western blot and bioluminescence resonant energy transfer technique for its interaction with the catalytic subunit.

RESULTS

MLPA allowed identification of exons 3-6 deletion in three patients of a family with typical CNC. The truncated protein is expressed, but rapidly degraded, and does not interact with the protein kinase A catalytic subunit.

CONCLUSIONS

MLPA is a powerful technique that may be used following the lack of mutations detected by direct sequencing in patients with bona fide CNC or PPNAD. We report here one such new deletion, as an example. However, these gene defects are not a frequent cause of CNC or PPNAD.

Moving toward personalized cell-based interventions for adrenal cortical disorders: part 1--Adrenal development and function, and roles of transcription factors and signaling proteins

Transdifferentiation of an individual's own cells into functional differentiated cells to replace an organ's lost function would be a personalized approach to therapeutics. In this two part series, we will describe the progress toward establishing functional transdifferentiated adrenal cortical cells. In this article (Part 1), we describe adrenal development and function, and discuss genes involved in these processess and selected for use in our pilot studies of transdifferentiation that are presented in the second article (Part 2).

The paradoxical increase in cortisol secretion induced by dexamethasone in primary pigmented nodular adrenocortical disease involves a glucocorticoid receptor-mediated effect of dexamethasone on protein kinase A catalytic subunits

CONTEXT

Primary pigmented nodular adrenocortical disease (PPNAD) results in most cases from mutations of the protein kinase A (PKA) regulatory subunit 1A (PRKAR1A) gene. Patients with PPNAD exhibit a paradoxical increase in cortisol secretion in response to dexamethasone.

OBJECTIVE

The aim was to investigate the mechanism of the action of dexamethasone on adrenocortical cells removed from patients with PPNAD and a transgenic model of PPNAD [Tg(tTA/X2AS) mice].

DESIGN AND SETTING

We performed an in vitro study in an academic research laboratory.

PATIENTS

Eleven patients with histologically proven PPNAD were included in the study.

INTERVENTION

Cultured PPNAD cells were incubated with dexamethasone in the presence of various modulators of the cAMP/PKA pathway and the glucocorticoid receptor antagonist RU486.

MAIN OUTCOME MEASURE

Cortisol and corticosterone were measured by radioimmunological assays in cell culture supernatants.

RESULTS

Dexamethasone stimulated in vitro cortisol secretion from PPNAD tissues in six patients. The stimulatory effect of dexamethasone on cortisol release was not reduced by the adenylyl cyclase inhibitor SQ22536 or potentiated by the phosphodiesterase inhibitor IMBX and the cAMP analog 8Br-cAMP. Conversely, the PKA inhibitor H89 and RU486 inhibited the cortisol response to dexamethasone. Dexamethasone had no effect on cortisol production from normal human adrenocortical cells but stimulated corticosteroidogenesis in the presence of RU486. Similarly, dexamethasone failed to influence corticosterone release by adrenocortical cells removed from Tg(tTA/X2AS) mice but stimulated corticosteroidogenesis in the presence of RU 486.

CONCLUSIONS

These results indicate that, in human PPNAD tissues, dexamethasone paradoxically stimulates cortisol release through a glucocorticoid receptor-mediated effect on PKA catalytic subunits.

New genes and/or molecular pathways associated with adrenal hyperplasias and related adrenocortical tumors

Over the course of the last 10 years, we have studied the genetic and molecular mechanisms leading to disorders that affect the adrenal cortex, with emphasis on those that are developmental, hereditary and associated with adrenal hypoplasia or hyperplasia, multiple tumors and abnormalities in other endocrine glands. On the basis of this work, we propose an hypothesis on how adrenocortical tumors form and the importance of the cyclic AMP-dependent signaling pathway in this process. The regulatory subunit type 1-alpha (RIalpha) of protein kinase A (PKA) (the PRKAR1A gene) is mutated in most patients with Carney complex and primary pigmented nodular adrenocortical disease (PPNAD). Phosphodiesterase-11A (the PDE11A gene) and -8B (the PDE8B gene) mutations were found in patients with isolated adrenal hyperplasia and Cushing syndrome, as well in patients with PPNAD. PKA effects on tumor suppression and/or development and the cell cycle are becoming clear: PKA and/or cAMP act as a coordinator of growth and proliferation in the adrenal cortex. Mouse models in which the respective genes have been knocked out see m to support this notion. Genome-wide searches for other genes responsible for adrenal tumors and related diseases are ongoing; recent evidece of the involvement of the mitochondrial oxidation pathway in adrenocortical tumorigenesis is derived from our study of rare associations such as those of disorders predisposing to adrenomedullary and related tumors (Carney triad, the dyad of paragangliomas and gastric stromal sarcomas or Carney-Stratakis syndrome, hereditary leiomyomatosis and renal cancer syndrome) which appear to be associated with adrenocortical lesions.

Heritable forms of hypertension

Among the causes of secondary hypertension are a group of disorders with a Mendelian inheritance pattern. Recent advances in molecular biology have unveiled the pathogenesis of hypertension in many of these conditions. Remarkably, the mechanism in every case has proved to be upregulation of sodium (Na) reabsorption in the distal nephron, with accompanying expansion of extracellular volume. In one group, the mutations involve the Na-transport machinery in distal tubule cells themselves: the distal convoluted tubule (DCT) cell and the principal cell of the collecting duct. Examples include Liddle's syndrome, with an activating mutation of epithelial Na channel (ENaC); two types of Gordon's syndrome, with mutations in two regulatory kinases [with no lysine (K) serine/threonine protein kinases (WNK)1 or WNK4]; and apparent mineralocorticoid excess (AME), with an inactivating mutation in the glucocorticoid-metabolizing 11beta-hydroxysteroid dehydrogenase type 2 enzyme (11HD2). In another group, abnormal adrenal steroid production leads to inappropriate stimulation of the mineralocorticoid receptor (MR) in the distal nephron. The pathophysiology may involve inappropriate production of aldosterone [in glucocorticoid-remediable aldosteronism (GRA) and familial hyperaldosteronism type II (FH II)], of cortisol (in familial glucocorticoid resistance), or of other steroid metabolites (in congenital adrenal hyperplasia and GRA). In contrast to earlier beliefs, hypertension in many of the inherited disorders may be mild, and electrolyte and acid-base abnormalities are often not present. Monogenic hypertension should therefore enter the differential diagnosis of any child or adolescent with hypertension. Plasma renin activity (PRA) is the appropriate screening tool for all types of inherited hypertension.

Case report of familial Carney complex due to novel frameshift mutation c.597del C (p.Phe200LeufsX6) in PRKAR1A

Carney complex is an autosomal dominantly inherited disease characterized by skin pigmentation, myxoma, primary pigmented nodular adrenocortical disease (PPNAD), and acromegaly. However, only a few incidences of PPNAD combined with acromegaly are observed in patients. The type 1alpha regulatory subunit of cAMP-dependent protein kinase (PRKAR1A) has been identified in patients as a causative gene for Carney complex by a positional cloning approach. Here, we report a female patient diagnosed with Cushing's syndrome and a GH-producing pituitary adenoma without otherwise evident acromegaly that could be diagnosed only by specialized endocrinological tests. Based on family history of acromegaly (mother and sister) and the fact that the combination of both diseases is very rare, genetic diagnosis involving Carney complex was considered to be appropriate. The 10 exons and flanking regions of PRKAR1A were screened for mutations by direct DNA sequencing. The patient and her mother and sister were found to have the same, novel frameshift mutation resulting from a single base deletion in exon 6 coding cAMP-binding domain A, denoted c.597delC in PRKAR1A. This single base deletion generated an immature stop codon at the sixth codon (p.Phe200LeufsX6). Even family members with the same mutation can show distinct phenotypes, suggesting that Carney complex is a multifactorial disorder comprising various genetic and environmental factors. Genetic diagnosis makes it possible to prepare more effective therapeutic strategies for patients and gene carriers and to avoid unnecessary tests for non-carriers in the family of the patient.

Expression of progesterone and estradiol receptors in normal adrenal cortex, adrenocortical tumors, and primary pigmented nodular adrenocortical disease

Adrenal tumors occur more frequently in women and are the leading cause of Cushing's syndrome during pregnancy. We aimed to evaluate the potential role of sex steroids in the susceptibility of women to adrenocortical tumors. We evaluated the presence of the progesterone receptor (PR), estradiol receptors (ERs), and aromatase in 5 patients with primary pigmented nodular adrenal disease (PPNAD), 15 adrenocortical adenomas (ACAs) and adjacent normal tissues, 12 adrenocortical carcinomas (ACCs), and 3 normal adrenal glands (NA). The expression of PR and ERalpha was evaluated by enzyme immunoassays, real-time RT-PCR, immunohistochemistry, and cytosol-based ligand-binding assays. ERbeta and aromatase levels were evaluated by real-time RT-PCR. ERalpha concentrations were low in NA, in adrenal tissues adjacent to ACA (51+/-33), in ACC (53+/-78), and lower in ACA (11+/-11 fmol/mg DNA). Conversely, PR concentrations were high in NA and adrenal tissues adjacent to ACA, at 307+/-216 fmol/mg DNA, and were even higher in tumors - 726+/-706 fmol/mg DNA in ACA and 1154+/-1586 fmol/mg DNA in ACC - and in isolated PPNAD nodules. Binding study results in four tumors were compatible with binding to a steroid receptor. In patients with PPNAD, a strong positive immunohistochemical signal was associated with the sole isolated nodular regions. ERbeta transcript levels were very high in all samples except those for two ACCs, whereas aromatase levels were low. PR and ERbeta are clearly present in normal adrenal glands and adrenal tumors. Further studies may shed light on the possible pathogenic role of these receptors in adrenal proliferation.

Protein kinase A subunit expression is altered in Bloom syndrome fibroblasts and the BLM protein is increased in adrenocortical hyperplasias: inverse findings for BLM and PRKAR1A

Bloom syndrome is a genetic disorder associated with chromosomal instability and a predisposition to tumors that is caused by germline mutations of the BLM gene, a RecQ helicase. Benign adrenocortical tumors display a degree of chromosomal instability that is more significant than benign tumors of other tissues. Cortisol-producing hyperplasias, such as primary pigmented nodular adrenocortical disease (PPNAD), which has been associated with protein kinase A (PKA) abnormalities and/or PRKAR1A mutations, also show genomic instability. Another RecQ helicase, WRN, directly interacts with the PRKAR1B subunit of PKA. In this study, we have investigated the PRKAR1A expression in primary human Bloom syndrome cell lines with known BLM mutations and examined the BLM gene expression in PPNAD and other adrenal tumor tissues. PRKAR1A and other protein kinase A (PKA) subunits were expressed in Bloom syndrome cells and their level of expression differed by subunit and cell type. Overall, fibroblasts exhibited a significant decrease in protein expression of all PKA subunits except for PRKAR1A, a pattern that has been associated with neoplastic transformation in several cell types. The BLM protein was upregulated in PPNAD and other hyperplasias, compared to samples from normal adrenals and normal cortex, as well as samples from cortisol- and aldosterone-producing adenomas (in which BLM was largely absent). These data reveal an inverse relationship between BLM and PRKAR1A: BLM deficiency is associated with a relative excess of PRKAR1A in fibroblasts compared to other PKA subunits; and PRKAR1A deficiency is associated with increased BLM protein in adrenal hyperplasias.

Adrenocorticotropic hormone-independent Cushing's syndrome

PURPOSE OF REVIEW

Endogenous Cushing's syndrome is adrenocorticotropic hormone (or corticotropin)-independent in 15-20% of cases. Primary Cushing's syndrome is most often secondary to adrenocortical adenomas or carcinomas, and more rarely to bilateral adrenal hyperplasias. Corticotropin-independent cortisol-producing hyperplasia is caused by micronodular diseases, including primary pigmented nodular adrenocortical disease and nonpigmented micronodular hyperplasia and adrenocorticotropic hormone-independent macronodular adrenal hyperplasia. Primary pigmented nodular adrenocortical disease can be found either alone or in the context of Carney complex, a multiple endocrine neoplasia syndrome.

RECENT FINDINGS

In recent years, the pathophysiology of adrenocortical tumors and hyperplasias became better understood following the identification of genes responsible for syndromes associated with corticotropin-independent Cushing's syndrome and the demonstration of aberrant expression and function of various hormone receptors in adrenocortical adenomas and adrenocorticotropic hormone-independent macronodular adrenal hyperplasia. This article reviews findings on the molecular and genetic aspects of corticotropin-independent Cushing's syndrome including recent gene expression profiling studies of adrenocortical tumors and hyperplasias and animal models that provided clues on the pathogenesis of primary Cushing's syndrome.

SUMMARY

A better understanding of molecular mechanisms involved in adrenocortical tumors and hyperplasias may lead to improved diagnostic and prognostic markers and treatment strategies to assist clinicians in the management of corticotropin-independent Cushing's syndrome.

Endogenous corticosteroid biosynthesis in subjects after bilateral adrenalectomy

OBJECTIVE

Corticosteroids can be synthesized in extra-adrenal tissues but the contribution of this to circulating levels in humans is not known. Previous in vitro studies suggest that the 'hybrid' corticosteroid 18-oxocortisol (18-oxoF) is produced from cortisol by aldosterone synthase. We looked for evidence of extra-adrenal production of this and other corticosteroids in 10 subjects stable on long-term glucocorticoid replacement following bilateral adrenalectomy.

METHODS

In phase 1, patients were maintained on cortisol alone (30 mg/day), in phase 2 dexamethasone (2 mg/day), and in phase 3, both cortisol and dexamethasone. Each phase lasted 3 days.

MEASUREMENTS

On the last day of each phase, 24-h urine collection was performed for analysis of steroid metabolite excretion [using gas chromatography-mass spectrometry (GCMS)] and plasma aldosterone and renin were measured (by radioimmunoassay).

RESULTS

Cortisol metabolite excretion rate [tetrahydrocortisone (THE) + tetrahydrocortisol (THF) + allotetrahydrocortisol (aTHF)] fell from 9169 nmol/24 h in phase 1 to 22 nmol/24 h in phase 2, rising to 6843 nmol/24 h in phase 3. Tetrahydroaldosterone (THAldo) excretion was readily detectable and did not alter significantly between phases (26.5, 23.5 and 28.5 nmol/24 h, respectively; P = 0.474). 18-Hydroxycortisol (18-OHF) excretion was easily detectable in phases 1 and 3 (252.5 and 212 nmol/24 h), falling in phase 2 (12 nmol/24 h). 18-oxoF excretion rates were lower but followed a similar pattern (1.62, 0.085 and 1.785 nmol/24 h in phases 1, 2 and 3, respectively).

CONCLUSIONS

Significant levels of adrenal steroids are found in adrenalectomized subjects. We speculate that this occurs at extra-adrenal sites or in residual adrenal cortex tissue in an ACTH-independent manner. Our data suggest that aldosterone synthase, acting on cortisol, is the source of 18-oxoF and 18-OHF in these subjects. Further studies of corticosteroid production within adrenalectomized subjects, looking for evidence of adrenal regrowth or residual adrenal tissue, are justified.

Depletion of type IA regulatory subunit (RIalpha) of protein kinase A (PKA) in mammalian cells and tissues activates mTOR and causes autophagic deficiency

The human PRKAR1A gene encodes the regulatory subunit 1-alpha (RIalpha) of the cAMP-dependent protein kinase A (PKA) holoenzyme. Regulation of the catalytic activity of PKA is the only well-studied function of RIalpha. Inactivating PRKAR1A mutations cause primary pigmented nodular adrenocortical disease (PPNAD) or Carney complex (CNC), an inherited syndrome associated with abnormal skin pigmentation and multiple neoplasias, including PPNAD. Histochemistry of tissues from CNC patients is indicative of autophagic deficiency and this led us to investigate the relationship between RIalpha and mammalian autophagy. We found that fluorescently tagged RIalpha associates with late endosomes and autophagosomes in cultured cells. The number of autophagosomes in prkar1a-/- mouse embryonic fibroblasts (MEFs) was reduced compared with wild-type MEFs. RIalpha co-immunoprecipitated with mTOR kinase, a major regulator of autophagy. Phosphorylated-mTOR levels and mTOR activity were dramatically increased in prkar1a-/- mouse cells, and in HEK 293 cells with RIalpha levels reduced by siRNA. Finally, phosphorylated-mTOR levels and mTOR activity were increased in CNC cells and in PPNAD tissues. These data suggest that RIalpha deficiency decreases autophagy by the activation of mTOR, providing a molecular basis to autophagic deficiency in PPNAD.

Strategies for the characterization of disorders in cortisol sensitivity

CONTEXT

The clinical presentation of abnormalities in glucocorticoid (GC) sensitivity is diverse, and therefore it is difficult to diagnose this condition.

OBJECTIVE AND DESIGN

The objective of the study was to develop strategies for the characterization of GC sensitivity disorders.

SETTING

The study was conducted in an outpatient clinic.

PATIENTS

Nine patients with GC sensitivity disorders participated.

INTERVENTIONS

Sequence analysis of the GC receptor (GR), determination of GR number per cell, GR ligand-binding affinity, and GR splice regulation were performed in freshly prepared peripheral blood mononuclear lymphocytes and Epstein-Barr virus-transformed lymphoblasts. Cellular GC sensitivity was determined ex vivo by measuring the effect of dexamethasone on GC-induced leucine-zipper and IL-2 mRNA levels and on cell proliferation.

RESULTS

Differences in GR number per cell, GR affinity, GR splice variants, and effects on transactivation or transrepression of GC-sensitive genes were observed between patients and controls. Epstein-Barr virus transformation of lymphoblasts had no influence on GR affinity but increased the GR number 5-fold in healthy controls. In patients diagnosed as cortisol resistant, however, GR number after transformation was increased significantly less than 5-fold, whereas a higher GR number was observed in a patient suspected of cortisol hypersensitivity.

CONCLUSION

This study illustrates several strategies to define abnormalities in GC sensitivity by describing nine patients with affected GC sensitivity, all with a unique clinical course and background.

Paradoxical inhibitory effect of serotonin on cortisol production from adrenocortical lesions causing Cushing's syndrome

In the human adrenal gland, serotonin (5-HT) stimulates cortisol production through a paracrine mechanism involving 5-HT4 receptors positively-coupled to adenylyl cyclase. A hyperresponsiveness of adrenocortical tissue to 5-HT has also been described in several cases of ACTH-independent bilateral macronodular adrenal hyperplasias (AIMAHs) and adenomas causing Cushing's syndrome. In the present study, we report two cases of cortisol-producing adrenocortical lesions, i.e., one AIMAH (case 1) and one adenoma (case 2), whose secretory activity was inhibited in vitro by 5-HT. The potencies (pIC50) and efficacies (Emax) of 5-HT to inhibit cortisol secretion were 8.2 +/- 0.4 and -64.1% +/- 7.5% in case 1, and 9.2 +/- 0.5 and -32.3% +/- 3.8% in case 2. The specific 5-HT4 antagonist GR 113808 failed to influence the 5-HT-induced decrease in cortisol production by the two tissues, indicating that the paradoxical inhibitory effect of 5-HT could not be accounted for by activation of eutopic 5-HT4 receptors. These results suggest that the tissues expressed aberrant 5-HT receptors. In conclusion, the present study provides the first evidence for an inhibitory effect of 5-HT on cortisol secretion in adrenocortical lesions causing Cushing's syndrome. Our data also suggest that expression of illegitimate membrane receptors by cortisol-producing adrenal hyperplasias and/or adenomas may convert a paracrine stimulatory factor into an inhibitory signal.

Adrenarche - physiology, biochemistry and human disease

Adrenarche refers to the onset of dehydroepiandrosterone (DHEA) and DHEA-sulphate (DHEA-S) production from the adrenal zona reticularis that can be detected at around 6 years of age. The phenotypic result of adrenarche is pubarche or the development of axillary and pubic hair that occurs in both girls and boys at about age 8. The phenomenon of adrenarche is unique to human beings and to some Old World primates, and a reversal of adrenarche appears to occur in the ageing process. Premature and exaggerated adrenarche can be indicative of future onset of adult diseases, thus increasing the clinical relevance of adrenarche. The physiological triggers of adrenarche and the role(s) of DHEA-S remain speculative. However, the biochemical pathways that define adrenarche have been characterized in detail, and the appearance of key enzymes and cofactors in the adrenal zona reticularis track with the progression of adrenarche. This article reviews the clinical manifestations of adrenarche, the biochemistry of the enzymes involved in DHEA-S production, and the cell biology of the adrenal zona reticularis.

Enhancement of Dehydroepiandrosterone Solubility and Bioavailability by Ternary Complexation with α‐Cyclodextrin and Glycine

In the present work we investigated the possibility of improving dehydroepiandrosterone (DHEA) solubility and bioavailability by high-energy cogrinding with alpha-cyclodextrin (alpha-Cd) in the presence or absence of different auxiliary substances (glycine, biomaltodextrin, poly(vinyl pyrrolidone), poly(ethylene glycol) 400). In all cases, ternary products exhibited higher drug solubilizing properties than the binary DHEA-alpha-Cd coground system. Glycine was the most effective component. The best combinations, corresponding to 1:1:2 and 1:2:3 drug-alpha-Cd-glycine molar ratios, were characterized by differential scanning calorimetry and X-ray powder diffractometry and evaluated for dissolution rate. The presence of glycine favored destruction of DHEA crystalline structure during cogrinding, as evidenced by the strong reduction in both time and vibration frequency of milling necessary to obtain total drug amorphization. Both ternary products showed better dissolution properties than the drug alone, affording, respectively, a 40 and 60% increase of dissolution efficiency. The 1:2:3 coground product was then selected for in vivo bioavailability studies in women suffering from adrenocortical insufficiency. DHEA and DHEA sulfate blood levels were significantly higher (p < 0.001) after oral administration of the coground product than after oral administration of untreated drug, with a 100% increase in the area under the curve (AUC) of concentration versus time. Moreover, the time to reach maximum concentration (t(max)) decreased from 2.2 with the untreated drug to 0.5 h with the coground product, and the mean permanence time of DHEA within physiological levels was four times longer for the coground product compared with the untreated drug. These results indicate that the developed product is particularly suitable for oral DHEA formulations in hormone replacement therapies.

Renal inactivation, mineralocorticoid generation, and 11beta-hydroxysteroid dehydrogenase inhibition ameliorate the antimineralocorticoid effect of progesterone in vivo

Progesterone (P) is a strong mineralocorticoid receptor (MR) antagonist in vitro. The high P concentrations seen in normal pregnancy only moderately increase renin and aldosterone concentrations. In previous in vitro studies we hypothesized that this may be explained by intrarenal conversion of P to less potent metabolites. To investigate the in vivo anti-MR potency of P, we performed an infusion study in patients with adrenal insufficiency (n = 8). They omitted 9alpha-fluorocortisol for 4 d and hydrocortisone for 0.5 d before a continuous iv infusion of aldosterone for 8.5 h, with an additional iv P infusion commenced at 4 h. During aldosterone infusions the initially elevated urinary sodium to potassium ratio decreased significantly. Despite the 1000-fold excess of P over aldosterone, the urinary sodium to potassium ratio and urinary sodium excretion increased only slightly after 3 h of P infusion. We detected inhibition of renal 11beta-hydroxysteroid dehydrogenase type 2 by P, thus giving cortisol/prednisolone access to the MR. Urinary and plasma concentrations of 17alpha-hydroxyprogesterone, a major metabolite of renal P metabolism, and those of serum androstenedione and deoxycorticosterone, a mineralocorticoid itself, increased significantly during P infusion. This supports the hypothesis of an effective protection of the MR from P by efficient extraadrenal downstream conversion of P.

Molecular cloning, chromosomal localization of human peripheral-type benzodiazepine receptor and PKA regulatory subunit type 1A (PRKAR1A)-associated protein PAP7, and studies in PRKAR1A mutant cells and tissues

A mouse protein that interacts with the peripheral-type benzodiazepine receptor (PBR) and cAMP-dependent protein kinase A (PKA) regulatory subunit RIalpha (PRKAR1A), named PBR and PKA-associated protein 7 (PAP7), was identified and shown to be involved in hormone-induced steroid biosynthesis. We report the identification of the human PAP7 gene, its expression pattern, genomic structure, and chromosomal mapping to 1q32-1q41. Human PAP7 is a 60-kDa protein highly homologous to the rodent protein. PAP7 is widely present in human tissues and highly expressed in seminal vesicles, pituitary, thyroid, pancreas, renal cortex, enteric epithelium, muscles, myocardium and in steroidogenic tissues, including the gonads and adrenal cortex. These tissues are also targets of Carney complex (CNC), a multiple neoplasia syndrome caused by germline inactivating PRKAR1A mutations (PRKAR1A-mut) and associated with primary pigmented nodular adrenocortical disease (PPNAD) and increased steroid synthesis. PAP7 and PRKAR1A expression were studied in PPNAD and in lymphoblasts from patients bearing PRKAR1A-mut. Like PRKAR1A, PAP7 was decreased in CNC lymphocytes and PPNAD nodules, but not in the surrounding cortex. These studies showed that, like in the mouse, human PAP7 is highly expressed in steroidogenic tissues, where it follows the pattern of PRKAR1A expression, suggesting that it participates in PRKAR1A-mediated tumorigenesis and hypercortisolism.

Synaptophysin immunoreactivity in primary pigmented nodular adrenocortical disease: neuroendocrine properties of tumors associated with Carney complex

Carney complex (CNC) is characterized by lentiginosis and myxomatosis together with a variety of endocrine, neural crest-derived, and other tumors, including primary pigmented nodular adrenocortical disease (PPNAD). PPNAD is characterized by lipofuscin-containing, autonomously functioning, cortisol-producing nodules surrounded by mostly atrophic adrenocortical and normal adrenomedullary tissue. The nature and origin of the tumors, including the myxomas and PPNAD, are unclear. In this study, seven paraffin-embedded PPNAD tumors, one skin myxoma, and two cell lines (one myxoma and one PPNAD) established from patients with CNC were stained with antisera for synaptophysin (SYN), neuron-specific enolase, chromogranin A, tyrosine hydroxylase, and the neural cell adhesion molecule (NCAM). In addition, one PPNAD specimen and one myxoma were analyzed by electron microscopy. The results showed that chromogranin A and tyrosine hydroxylase stained adrenomedullary tissue, but not the PPNAD nodules or the extranodular adrenal cortex. SYN, neuron-specific enolase, and NCAM also stained the medulla. PPNAD nodules and the PPNAD cell line, but not the extranodular adrenal cortex, stained intensely for SYN. The myxoma cell line, but not normal fibroblasts, stained for SYN and NCAM. Ultrastructural analysis of a PPNAD tumor and a skin myxoma revealed a well developed rough endoplasmic reticulum, prominent mitochondria, and vesicle-like structures dispersed throughout the cytoplasm. We conclude that immunostaining for SYN, a marker protein for neuroendocrine cells, clearly distinguishes PPNAD nodules from surrounding adrenocortical tissue and can be helpful in the detection of small nodules in apparently unaffected cortex. The cells of a cutaneous myxoma were also stained positive by two of the three neuroendocrine markers. Finally, both PPNAD and myxoma cells demonstrated ultrastructural features suggestive of neuroendocrine properties. These results support the previously suggested hypothesis that the genetic mechanism leading to CNC involves genes with a neuroendocrine role.

Relationships between environmental organochlorine contaminant residues, plasma corticosterone concentrations, and intermediary metabolic enzyme activities in Great Lakes herring gull embryos

Experiments were conducted to survey and detect differences in plasma corticosterone concentrations and intermediary metabolic enzyme activities in herring gull (Larus argentatus) embryos environmentally exposed to organochlorine contaminants in ovo. Unincubated fertile herring gull eggs were collected from an Atlantic coast control site and various Great Lakes sites in 1997 and artificially incubated in the laboratory. Liver and/or kidney tissues from approximately half of the late-stage embryos were analyzed for the activities of various intermediary metabolic enzymes known to be regulated, at least in part, by corticosteroids. Basal plasma corticosterone concentrations were determined for the remaining embryos. Yolk sacs were collected from each embryo and a subset was analyzed for organochlorine contaminants. Regression analysis of individual yolk sac organochlorine residue concentrations, or 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs), with individual basal plasma corticosterone concentrations indicated statistically significant inverse relationships for polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs), total polychlorinated biphenyls (PCBs), non-ortho PCBs, and TEQs. Similarly, inverse relationships were observed for the activities of two intermediary metabolic enzymes (phosphoenolpyruvate carboxykinase and malic enzyme) when regressed against PCDDs/PCDFs. Overall, these data suggest that current levels of organochlorine contamination may be affecting the hypothalamo-pituitary-adrenal axis and associated intermediary metabolic pathways in environmentally exposed herring gull embryos in the Great Lakes.

Juxta-adrenal cortical cell nests or nodular formation in the younger generation: what does it mean?

The number and size of juxta-adrenal cortical cell nests or nodular formation (JACN) and their histology were examined in autopsy material from 255 successive subjects of various ages (from fetuses to elderly patients). The study of number and size showed that JACN occurred significantly more frequently among subjects aged 0-year-old (0Y0) to 10Y0 (p < 0.01) than among other age groups. The study of numbers within each nodular size range (large nodular formations [LNF; nodules with a minor axis measuring 0.25 mm or more] and small nodular formations [SNF; smaller than LNF]) showed that the number of SNF and the SNF to LNF ratio decreased according to age, while the number of LNF remained relatively constant. Immunohistochemical examination of proliferating adrenal cortical cells using the mouse anti-human antibody MIB-1 demonstrated many positive cells in subjects with many JACN. No nodular proliferation of adrenocorticotrophic hormone positive cells occurred in the adenohypophysis. Fibrous thickening of the adrenal capsule increased gradually with age or medication. JACN was very frequently observed among subjects with conditions such as asplenic syndrome, acute lymphocytic leukemia and Down's syndrome. These data suggest that JACN might be an anatomic variant but that certain factors could increase the size and number of JACN after birth.

[A case of Cushing's syndrome caused by primary pigmentary nodular hyperplasia]

Primary pigmented nodular adrenocortical disease is a rare cause of Cushing's syndrome in children and young adults. It is characterized by hypercorticolism resistant to dexamethasone suppression and at microscopic examination by multiple small black cortical nodules containing large cells with eosinophilic cytoplasm and lipofuscin with internodular cortical atrophy. Its pathogenesis is unknown. Bilateral adrenalectomy is the treatment of choice. We report a case of Cushing's syndrome due to primary pigmented nodular adrenocortical disease in a 32 year old female and review the literature.

Growth hormone receptor messenger ribonucleic acid in normal and pathologic human adrenocortical tissues--an analysis by quantitative polymerase chain reaction technique

GH receptor (GHR) has been reported to express in both normal rat and human adrenals. However, no study examined GHR expression in diseased human adrenal cortex. We quantitated, with RT-PCR, GHR messenger RNA (mRNA) in both normal and diseased human adrenal cortex with the following results: GHR mRNA levels in four histologically normal, not steroid-stimulated, control adrenal cortices was 1.5-11 x 10(4) molecules/microgram total RNA; in three diffusely hyperplastic adrenals (DH): 6.7-17.7 x 10(4); in two nonfunctioning tumors (NF): 0.84-1.9 x 10(4); in five androgen-producing neoplasms (AP): 4.6-34 x 10(4); and in five glucocorticoid-producing neoplasms (GP): 6.7-87 x 10(4). GHR transcript levels among adrenal cortices, DH, NF, AP, and GP reached statistically significant difference (P < 0.03). The GP group exhibited higher GHR mRNA levels than controls (P < 0.006). NF, as well as GP and AP, tumors had less GHR mRNA than their histologically normal adjacent cortex (P < 0.05). A positive correlation between urinary cortisol and GHR messenger RNA (mRNA) levels from GP and DH was observed (r = 0.93, P < 0.003). Our data suggest that GHR is expressed in both normal and diseased adrenal cortex and that GHR mRNA accumulation is less efficient in adrenocortical neoplasm than their adjacent nonneoplastic cortex. GHR expression in adrenal cortex provides an evidence of direct GH action in this tissue.

A critical review of the origin and control of adrenal androgens

The reticularis and fasciculata zones of the adrenal cortex are the predominant sources of dehydroepiandrosterone (DHEA) and DHEA-sulphate and contribute directly or indirectly 60-75% of androstenedione and testosterone in women. The specific control of adrenal androgens remains unclear. While ACTH stimulates adrenal androgen secretion, the dissociation of cortisol and androgens occurring during adrenarche and under pathological conditions suggests other factors are involved. Recent studies using human adrenal cells in vitro have demonstrated that the ratio of androgen to cortisol produced is substantially independent of the age and gender of the adrenal, indicating that extra-adrenal factors are of greater importance. beta-Endorphin and joining peptide have been shown to stimulate androgen production in human adrenal cells and to influence ACTH-stimulated steroidogenesis in a manner that promotes adrenal androgen production. The activity of these pro-opiomelanocortin-derived peptides may explain the physiological and pathological dissociations of androgens and cortisol.

'Exaggerated adrenarche' in children presenting with premature adrenarche

OBJECTIVE

Previous reports of endocrinological profiles in children presenting with premature adrenarche have not shown consistent abnormalities. We therefore aimed to review the clinical and biochemical aspects of a large number of patients presenting with premature adrenarche without virilization and determine the relation between clinical and biochemical characteristics and the frequency of adrenal steroid disorders.

DESIGN AND PATIENTS

Eighty-eight patients presenting with adrenarche without virilization during 1985-1992 were retrospectively reviewed. There were 72 girls and 16 boys. All were normotensive and had either prepubertal breasts or testes < 4 ml. In patients with high adrenal androgen levels, adrenal tumours had been excluded by either adrenal ultrasound or CT scan.

MEASUREMENT

We recorded clinical manifestations, auxological data, bone age, biochemical results including basal 17OH-progesterone (b17OHP), dehydroepiandrosterone sulphate (DHEAS), androstenedione (delta 4A), testosterone, cortisol and stimulated 17OHP and cortisol. ACTH stimulation tests (using soluble Synacthen 250 micrograms intramuscularly and collecting blood at 0, 30 and 60 minutes) were performed when clinically indicated. 17OH-Pregnenolone (17OHPreg) was also measured during ACTH stimulation tests in 13 individuals to look for abnormalities of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD).

RESULTS

The age of onset ranged from 3 to 9.5 years (mean 6.8 +/- 1.3). There were no significant differences by sex for height SDS, weight SDS or % ideal body weight, but bone age advancement was greater in males (P < 0.02). The most common presenting clinical manifestation was premature appearance of pubic hair in 93.8%, the other 6.2% presenting with body odour, acne and/or hirsutism. Twelve patients had b17OHP > 6 nmol/l of whom 5 were diagnosed as having congenital adrenal hyperplasia (CAH) resulting from 21-hydroxylase deficiency after ACTH stimulation tests. A further 33 patients who had b17OHP < 6 nmol/l had normal 17OHP and cortisol responses to ACTH stimulation. Patients, after excluding those with CAH, were divided on the basis of their DHEAS levels into prepubertal (< 1.5 mumol/l), pubertal (1.5-6 mumol/l) and above pubertal range (> 6 mumol/l). The 8 patients with DHEAS values above the pubertal range were described as having 'exaggerated adrenarche'. There were no significant clinical differences between these 3 groups, but significant differences were found for bone age advancement and the steroids, b17OHP, delta 4A and testosterone. There was a strong correlation between DHEAS and delta 4A (r = 0.623, P < 0.001). The 'exaggerated adrenarche' group had higher 17 OHPreg/17OHP ratios at 60 minutes after stimulation but these were not diagnostic for 3 beta-HSD deficiency.

CONCLUSION

The value of assessing basal steroids in children presenting with premature adrenarche is demonstrated in this series with 5.7% being diagnosed with 21-hydroxylase deficiency and 9.1% with 'exaggerated adrenarche'. No relation was found between adrenal steroids and clinical features except for the acceleration of bone age. The relation between 'exaggerated adrenarche' and future ovarian hyperandrogenism needs further evaluation.

Association of arginine vasopressin-secreting cell, steroid-secreting cell, adrenal and islet cell antibodies in a patient presenting with central diabetes insipidus, empty sella, subclinical adrenocortical failure and impaired glucose tolerance

A 36-year-old woman with central diabetes insipidus (DI), diagnosed when she was 7, was referred to our Endocrine Unit in January 1993 for further hormonal investigations. Clinical and laboratory findings confirmed the diagnosis of central DI. Cranial computed tomography and magnetic resonance imaging showed only an empty sella. Moreover, we noted impaired glucose tolerance and unusual findings of subclinical adrenocortical failure, i.e. high plasma renin activity with normal aldosterone levels, high ACTH despite normal basal and ACTH-stimulated cortisol levels. Immunological study of the patient's serum showed the presence of arginine vasopressin (AVP)-secreting cell antibodies (Abs), steroid-producing cell Abs, adrenal and islet cell Abs. The following aspects of our case are stressed and discussed: (1) the presence of AVP-secreting cell Abs 29 years after the diagnosis of DI; (2) the association between DI, empty sella and subclinical autoimmune adrenocortical failure with unusual hormonal findings, and (3) impaired glucose tolerance with islet cell antibody positivity.

[Endocrine pathological analysis of primary pigmented nodular adrenocortical disease]

We have studied eleven cases of the adrenal with primary pigmented nodular adrenocortical disease (PPNAD) by immunohistochemistry of all steroidogenic enzymes involved in cortisol biosynthesis, by in situ hybridization of P450C17 in seven cases in order to localize the sites of steroidogenesis and by chromosome suppression in situ hybridization of genomic DNA in five cases in order to determine possible genetic abnormalities of the disorder. Immunoreactivity of all the enzymes examined was intense in almost all the cells in adrenocortical nodules while internodular adrenal cortex, including the cases without cortical atrophy, was negative for the enzymes with the exception of 3 beta HSD. In situ hybridization studies of P450C17 yielded results consistent with those of immunohistochemistry. These results may be consistent with autonomous cortisol production by the nodular cells and indicate that almost all of the cells in the cortical nodules produce cortisol, which can explain the presence of hypercortisolism despite small sizes of adrenals in PPNAD. Chromosome suppression in situ hybridization analysis demonstrated possible genetic defects in chromosome 16 in this disorder.

Glucocorticoid receptor abnormalities in fibroblasts from patients with idiopathic resistance to dexamethasone diagnosed when evaluated for adrenocortical disorders

A retrospective survey was accomplished on 420 consecutive patients who had undergone dexamethasone suppression tests between 1975-1988 due to suspected adrenal disorders. We found 7 patients in whom glucocorticoid resistance was apparent. They showed 4-6 abnormalities of the 7 investigations used: insensitivity to dexamethasone inhibition (n = 7), increased urinary cortisol (n = 3), glucocorticoid receptor (GR) thermolability (n = 4), decreased number of glucocorticoid receptors (n = 4), abnormal ligand affinity of GR (n = 4), abnormal basal GR mRNA expression (n = 4), and abnormal down-regulation of basal GR mRNA levels by dexamethasone (n = 1). The four patients with GR thermolability also showed increased basal GR mRNA levels. In the other patients the number of GR per cell was decreased without an up-regulation of GR mRNA. It is concluded that the syndromes of glucocorticoid resistance vary notably, clinically as well as biochemically; in patients evaluated for adrenocortical disorders the syndrome is apparently encountered in 1-2% of the patients.

[Effect of vibration on gamma-aminobutyric acid metabolism in the brain in various functional conditions of the adrenal cortex]

The low-frequency vibration during 30 min (20 Hz, A = 0.4 mm) has been studied for its influence on the level of components of the GABA system and dicarbonic ++amino acids in male rats at hypo- and hyperfunction of the adrenal cortex. It is shown that under these conditions of the experiment the GABA level and glutamate-decarboxylase activity increase. Hyperfunction of the adrenal cortex against the background of vibration causes a relatively less pronounced increase in the GABA content, than the vibration alone or against the background of inhibition of adrenocortical function in the organism.

Primary bilateral adrenocortical causes of Cushing's syndrome

Nontumorous primary adrenal causes of Cushing's syndrome are exceedingly rare. Herein we review our results with seven patients in whom there is biochemical evidence of a primary (adrenocorticotropin independent) bilateral adrenal cause of endogenous hypercortisolism. Each patient had low plasma adrenocorticotropin levels. All patients had elevated 24-hour urinary free cortisol levels and 17-hydroxycorticosteroids that were not suppressed by high-dose dexamethasone. Plasma levels of adrenocorticotropin and cortisol were not elevated by ovine corticotropin-releasing factor. No patient had a gradient between petrosal and peripheral adrenocorticotropin levels. No pituitary tumors were detected by magnetic resonance imaging or computed tomography. Five of six patients who underwent iodocholesterol scanning showed bilateral adrenal activity. Computed tomographic and magnetic resonance imaging of the abdomen demonstrated bilateral small adrenal glands in three patients, an adrenal mass in one patient with Carney's complex, and massively enlarged glands in three patients. Each patient underwent bilateral adrenalectomy and was given glucocorticoid and mineralocorticoid replacement. Pathologic examination of four of these bilateral adrenal specimens revealed primary pigmented micronodular adrenocortical disease, with adrenal gland weights between 2.5 and 13.4 gm (mean 5.2 gm). However, the remaining three patients had primary adrenocorticotropin-independent bilateral macronodular adrenocortical disease with adrenal gland weights between 32 and 81 gm (mean 52 gm). Although each of the patients with primary pigmented micronodular adrenocortical disease was cured by bilateral adrenalectomy through a posterior approach, two of the three patients required an anterior approach. We conclude that Cushing's syndrome can arise through two distinct forms of primary bilateral adrenal cortical disease. Computed tomography is important in evaluation of these patients because the size of the adrenal glands influences the surgical approach.

Steroid characteristics of mineralocorticoid adrenocortical hypertension

Adrenocortical causes of hypertension are established by examining the mineralocorticoid hormones produced in the zona glomerulosa and zona fasciculata. In the zona glomerulosa, aldosterone excess leads to hypertension, hypokalemia, and suppressed plasma renin activity, with increased concentrations of urinary aldosterone (either as the 18-glucuronide or free aldosterone) as an index of its production. Identifying a tumor by computed tomography scan verifies the diagnosis of a correctable lesion. If no tumor is found, several maneuvers are used to identify primary adrenal hyperplasia, a disorder with autonomous aldosterone production, for which reduction of adrenal mass is curative. The zona fasciculata has two major pathways: the 17-deoxy pathway, where deoxycorticosterone (DOC) and corticosterone are the significant steroids, and the 17-hydroxy pathway, which leads to cortisol production. Tumors of the 17-deoxy pathway, DOC-producing adenomas, have increased concentrations of DOC and its precursor steroids, normal concentrations of cortisol, and suppression of aldosterone production secondary to suppression of the renin system. Two enzymatic defects in the zona fasciculata, 11 beta- and 17 alpha-hydroxylase deficiency, can be first readily identified by the virilization in the former, hypogonadal features in the latter. Steroid patterns are diagnostic. DOC is produced in excess in both deficiencies and is the cause of the hypertension. Deficient or impaired 11 beta-hydroxy steroid dehydrogenase in the apparent mineralocorticoid excess syndrome or after licorice ingestion retards the conversion of cortisol to inactive cortisone in the kidney, leading to mineralocorticoid hypertension; this leads to suppression of the renin system and subsequently of aldosterone.

Familial Cushing's syndrome due to nodular adrenocortical dysplasia is an inherited disease of immunological origin

Circulating immunoglobulins may be involved in the pathogenesis of familial Cushing's syndrome due to nodular adrenocortical dysplasia. The disease may also be part of a complex including cutaneous and cardiac myxomas, spotty pigmentation of the skin, and other signs of endocrine overactivity. In the present study of two sisters treated by complete adrenalectomy for Cushing's syndrome due to nodular adrenocortical dysplasia, and of their first-degree relatives, no evidence of associated disorders was present. However, the serum of both girls and of their mother contained immunoglobulins capable of stimulating adrenal DNA synthesis and cortisol production in vitro. The study supports the theory that familial Cushing's syndrome due to adrenocortical dysplasia is an inherited disease of immunological origin.

[ACTH secretion in adrenocortical disorders]

Secretion of cortisol is under stimulatory regulation by ACTH, and cortisol secreted, in turn, inhibits ACTH secretion by the pituitary. Therefore, measurement of plasma ACTH is indispensable in the diagnosis of the adrenocortical diseases. The adrenal cortex is included in the hypothalamo-adenohypophysial-adrenocortical system, and the pathogenesis of these disorders must be evaluated. An interaction between the hypothalamo-adenohypophysial-adrenal system and the immune system have been suggested. We studied the effect of interleukin-1 (IL-1) on ACTH secretion by cultured rat pituitary cells in vitro. Our results suggest that IL-1 stimulates the ACTH secretion by enhancing its synthesis by the pituitary, rather than ACTH release.

Immunohistochemical study of cytochrome P-45017 alpha in human adrenocortical disorders

Cytochrome P-450 specific for steroid 17 alpha-hydroxylation (P-45017 alpha) was immunolocalized in normal and hyperfunctioning adrenal glands of pigs, bovines, and humans, using a specific IgG fraction raised against the enzyme. P-45017 alpha was present in the zona fasciculata (ZF) and zona reticularis (ZR), but not in the zona glomerulosa (ZG), in pig, bovine, and human adrenal glands. In the adrenal glands of patients with Cushing's disease, the positive immunoreactivity to P-45017 alpha was intense in ZF and ZR, particularly in cortical micronodules, corresponding to the sites of active steroidogenesis. Cells of hyperplastic ZG and outer ZF in the adrenal glands of idiopathic hyperaldosteronism were negative for P-45017 alpha. In aldosteronoma, positive immunoreactivity was observed in some tumor cells, which is consistent with cortisol production and its responsiveness to ACTH in aldosteronoma. In the attached adrenal glands of aldosteronoma, the immunoreactive P-45017 alpha was clearly present in the inner ZF and ZR, suggesting persistent androgen production. In Cushing's adenoma, the positive immunoreactivity was intense in tumor cells, and the ZR of the attached adrenal glands was weakly immunoreactive.

A retrospective study of aldosterone secretion in normal and adrenopathic dogs

A retrospective study on stored plasma from normal dogs and dogs with pituitary dependent hyperadrenocorticism (PDH), pituitary dependent hyperadrenocorticism controlled by mitotane (o,p'-DDD),* iatrogenic hyperadrenocorticism, and hypoadrenocorticism was conducted to determine if alterations in aldosterone production exist in these disorders. The plasma aldosterone concentration (PAC) was measured by radioimmunoassay immediately before and 1 hour after adrenocorticotropic hormone (ACTH) administration (0.5 IU/kg, intravenously [IV]). PACs increased significantly when ACTH was administered to normal dogs. Dogs with PDH had a lower baseline PAC, but their PAC increased to levels similar to that of normal dogs after ACTH administration. In dogs with PDH controlled by o,p'-DDD therapy, the response to ACTH was significantly less than that of normal dogs or dogs with untreated PDH. Dogs with iatrogenic hyperadrenocorticism had a lower baseline and post-ACTH PAC than normal dogs. Dogs with hypoadrenocorticism had a normal basal PAC, but showed no significant increase in PAC following ACTH administration. These findings suggest that PACs are significantly altered in a variety of adrenal diseases, and that the ACTH stimulation test may be useful when evaluating aldosterone secretion in adrenopathic disorders. In addition, at therapeutic dosages, o,p'-DDD treatment was associated with a decrease in basal and post-ACTH PACs in dogs with PDH.

In vitro adrenal cortex lesions characterization by NMR spectroscopy

Percentage of lipid content of 22 adrenal cortex lesions and their water proton longitudinal relaxation time were measured in vitro at 60 MHz. Although water relaxation times obtained on benign and malignant samples overlap each other, measurements of the percentage of lipids performed on the same tissues allow us to distinguish the two pathologies. The specific tool of characterization should be possible to obtain through in vivo spectroscopic imaging techniques.

Cushing's syndrome resulting from primary pigmented nodular adrenocortical disease

In a 10-year-old boy with Cushing's syndrome, the dexamethasone suppression test, the metyrapone test, and both basal and corticotropin-releasing factor-stimulated corticotropin levels all indicated a primary adrenal disorder. However, a computed tomographic scan failed to detect an adrenal tumor. At surgery, the adrenal glands were not enlarged but were studded with small pigmented nodules composed of enlarged nonmalignant adrenocortical cells. This unusual abnormality, referred to as primary pigmented nodular adrenocortical disease, is associated with autonomous hypersecretion of cortisol primarily in children and young adults. Our patient was cured by total bilateral adrenalectomy and corticosteroid replacement therapy, the treatment of choice for this condition.

Disorders of the adrenal cortex: their effects on electrolyte metabolism

The adrenal cortex is an important factor in the control of electrolyte and water balance and in blood pressure homeostasis. Not surprisingly, therefore, hyper- and hyposecretion of one or more of its products has extensive repercussions. Hypersecretion of aldosterone, as seen in primary hyperaldosteronism and related diseases, and of other mineralocorticoids such as corticosterone and/or 11-deoxycorticosterone, as seen in 17 alpha-hydroxylase deficiency or 11 beta-hydroxylase deficiency syndromes, respectively, are associated with hypertension, sodium retention, potassium wastage and a metabolic alkalosis. On the other hand, impaired secretion, as in Addison's disease or in congenital deficiencies of other steroid-synthesizing enzymes, leads to hypotension, sodium loss with hypovolaemia, and hyperkalaemia. In each case, these disturbances of electrolyte metabolism may cause neurological and muscle dysfunction. The relationship between glucocorticoid hypertension and electrolyte metabolism is less clear and the importance of the adrenal cortex in the aetiology of essential hypertension is still being assessed.

[Pharmacokinetics of prednisolone in adrenal insufficiency ]

Prednisolone was measured in serum and urine after oral and intravenous administration of prednisone and prednisolone in 16 patients with adrenal insufficiency and after bilateral adrenalectomy. Thus, the problem of cross-reactivity with endogenous steroids, the main factor disturbing the measurement of prednisolone, was completely eliminated. Prednisolone was detected by a simple competitive protein-binding radioassay. Distribution, elimination and other bioavailability parameters were calculated from the obtained data. No significant differences between serum levels were detected after oral administration of these drugs. Peak levels were reached after 2-3 h. After 5, 7.5 and 10 mg prednisone peak serum levels averaged 11.9 +/- 2.2, 15.9+/-3.4 and 21.5+/-5.9 microgram/dl, respectively. Prednisolone was still detectable 24 h after administration of 10 mg. The plasma half-time of approximately 5 1/2 h suggests that prednisolone is present in serum far about 2 days after application of higher doses. Since prednisolone interferes in most assays for cortisol, prednisone therapie has to be stopped at least 2 days before cortisol determinations. Urinary excretion was proportional to the applicated doses. The metabolic clearance rate of prednisolone was decreased (56.0+/-7.2 1/24 h/m2) in patients with adrenal insufficiency. This can be attributed to alterations in corticosteroid metabolism, probably due to an increased transcortin production.

Plasma cortisol response to thyrotrophin releasing hormone and luteinizing hormone releasing hormone in healthy kennel dogs and in dogs with pituitary-dependent hyperadrenocorticism

The change in the plasma concentration of cortisol after the administration of thyrotrophin releasing hormone (TRH) and LH releasing hormone (LH-RH) was studied in normal dogs and in dogs with pituitary-dependent hyperadrenocorticism (PDH). The normal dogs showed a small but significant increase in the plasma concentration of cortisol 15 min after intravenous injection of TRH and LH-RH. In ten of the dogs with PDH the response to TRH was not significantly different from that in the normal dogs, but in 13 the response was significantly greater. In 15 of the dogs with PDH the response to LH-RH administration was within or below the range of responses in the normal dogs and in only one dogs was the response to LH-RH greater than that in the normal dogs. These findings are discussed in relation to the pathogenesis of PDH.

Human corticosteroid binding globulin

The literature on corticosteroid binding globulin (transcortin) in the human is reviewed under the following headings: physicochemical properties, biosynthesis, measurement, and physiological, pharmacological and pathological variations with particular emphasis of the effects of pregnancy and oral contraceptives. Finally, the physiological implications of corticosteroid binding globulin are discussed.

New phenotypic variant of adrenoleukodystrophy. Pathologic, ultrastructural, and biochemical study in two brothers

Adrenoleukodystrophy is not usually considered in the differential diagnosis of the infantile onset of failure to thrive with motor and intellectual retardation. Rather, symptoms have started in childhood and have progressed over some years; not all patients have had overt adrenocortical insufficiency. The two brothers reported here developed symptoms in the neonatal period. In each the nature of the primary cerebral disorder was not recognized, because other etiologic factors clouded the diagnostic studies. In the younger brother, Case 1, a high titer (1:256) for cytomegalovirus (CMV) led to the suspicion that CMV infection accounted for the neurologic and ophthalmologic findings. Progressive neurologic deterioration at the age of 6 years prompted brain biopsy to confirm the diagnosis of progressive CMV encephalitis. In the older brother, Case 2, hemogenic hydrocephalus due to traumatic birth injury was held responsible for the psychomotor retardation and cerebral palsy. At necropsy, the adrenal glands in both cases were severly atrophic. In Case 1, a markedly inflammatory leukodystrophic process affected chiefly the frontal centra semiovalia and internal capsules, with relative sparing of parieto-occipital white matter and subcortical U-fibers. Heavy lymphocyte and monocyte cuffs surrounded many blood vessels in the white matter, and oil-red-O and PAS-positive macrophages were scattered in the zones of myelin disintegration and loss. Focally, the leukodystrophic process was so intense that cavitation necrosis was present, especially in the internal capsules. Further, PAS-positive, striated macrophages were aggregated in large clusters in liver, spleen, and lymph nodes. At the ultrastructural level, linear and gently arced, parallel, coapted or widely separated leaflets measuring 3-4 nm in width were identified in macrophages of the brain biopsy and in autopsy liver and lymph node. Biochemical analysis of fresh, frozen autopsy brain demonstrated cholesterol esters with long-chain fatty acids by thin-layer and gas-liquid chromatography. In Case 2, the leukodystrophic process could be readily identified in the brainstem and cerebellum but was masked in the cerebral hemispheres by the extensive hydrocephalus. The adrenal glands were atrophic and at light microscopy revealed adenomatoid nodules, many ballooned coritcal cells and very rare cells with striated cytoplasm. Masses of PAS-positive macrophages were encountered in liver and lymph nodes. In both cases, only old Wallerian degeneration of the corticospinal tracts was found in the spinal cord.