Adrenal Rests in the Uro-genital Tract of an Adult Population

Ectopic adrenal rests are a rare condition which can be found in various sites, generally in the retroperitoneum or pelvis along the path of gonadal descent. Their real prevalence is unknown. Males are more commonly affected, at least in the pediatric age. Adrenal rests are usually clinically silent and incidentally found in surgical samples, mostly in the pediatric population, and rarely in adults. With the aim of increasing knowledge and estimating the prevalence of ectopic adrenocortical tissue in the adult population, 44 adrenal rests in the urogenital tract of 40 adults are described. These represent approximately 0.07% of the total number of urogenital and gynecological surgeries performed in the 22 considered years. Adrenal rests were identified in the spermatic cord (10 males) and in paraovarian, parasalpingeal, or infundibulopelvic ligament locations (30 females). All but one was incidental findings. One case regarded an adrenocortical carcinoma arisen in adrenal rests. A literature review of adrenal ectopia in the urogenital tract of adults identified 57 reported cases from 53 patients, with similar clinicopathological features as those of our series, with the exception of a lower incidence of parasalpingeal locations. Despite their limited clinical implications, awareness of ectopic adrenal rests is essential also in adults for at least two reasons: (a) to correctly identify sources of adrenocortical hormone production in case of adrenal insufficiency or hormonal imbalance and (b) to avoid misinterpretations in the diagnostic workup of renal cell carcinoma, adrenocortical tumors, and rare gonadal neoplasms, including Sertoli/Leydig cell tumors.

Melanocortin 2 Receptor Antagonists in Canine Cushing’s Disease: In Vitro Studies

Melanocortin 2 receptor antagonists in canine Cushing’s disease: in vitro studies Cushing’s disease (CD), caused by an ACTH-secreting pituitary adenoma, is one of the most common endocrinopathies in dogs. The current medical treatment options involve adrenocortical steroid synthesis inhibitors, but a selective targeted approach to block ACTH receptor at its receptor would be much more attractive. The objective of this study was to preclinically investigate the effect of MC2R antagonists on adrenocortical hormone production, cell viability, and mRNA expression of steroidogenic enzymes in canine primary adrenocortical cell cultures from adrenal glands of healthy dogs. Three different MC2R antagonists were used: CRN.1, CRN.2, and CRN.4. Canine primary adrenocortical cell cultures (n = 8) were incubated with 50 nM ACTH for 24h, to mimic CD. Thereafter, 10 nM (IC50) and 2 μM (maximal concentration) of CRN.1, CRN.2, and CRN.4 were added. The two concentrations were established based on preliminary studies. After 24 hours of incubation, adrenocortical hormone concentrations were measured in the culture medium using liquid chromatography-mass spectrometry. RNA was isolated from the cells using the RNeasy Microkit (Qiagen) for subsequent real-time quantitative PCR analysis. Cell viability was assessed after 24 hours of incubation using alamarBlue™ Cell Viability Reagent. All CRN compounds effectively inhibited cortisol concentrations, while leaving aldosterone concentrations unaffected. In incubations with a maximal concentration of the three compounds, cortisol concentration decreased to undetectable levels. The mRNA expression levels of steroidogenic enzymes StAR, CYP11A1, CYP17A1, HSD3B2, CYP21, and CYP11B were significantly inhibited in most conditions when compared to the ACTH-stimulated control. The mRNA expression of melanocortin 2 receptor accessory protein (MRAP) was suppressed as well. Cell viability was not affected by CNR.1 or CNR.4, but was slightly inhibited by CRN.2. In summary, canine adrenocortical cell culture is a useful model system for drug testing. Incubation with MC2R antagonists demonstrated the potential of CNR.1 and CNR.4 as new treatment options for CD. Future in vivo studies in dogs with spontaneous CD are indicated.

Obesity-associated lipidomic remodeling of the adrenal gland indicates an important role of the FADS2-arachidonic acid axis in adrenocortical hormone production

ObjectiveAdrenocortical hormone levels increase in obesity, potentially contributing to development of obesity-associated pathologies. Here we explored whether lipidomic remodeling of the adrenal gland could mediate altered adrenocortical steroidogenesis during obesity.MethodsLipidomic analysis was performed in adrenal glands using shotgun mass spectrometry (MS), and steroid profiling of sera by liquid chromatography tandem mass spectrometry (LC-MS/MS) from lean and obese mice. Gene expression analysis was performed in adrenal glands and adrenocortical cell populations. The role of Fatty Acid Desaturase 2 (FADS2) and arachidonic acid on steroid hormone production was studied in primary adrenal gland cell cultures.ResultsAdrenal glands of obese mice displayed a distinct lipidomic profile, encompassing longer and more unsaturated storage lipids and phospholipids compared to adrenal glands of lean mice. Arachidonoyl acyl chains were abundant in the adrenal gland phospholipidome and increased upon obesity. This was accompanied by increased Fads2 expression, the rate-limiting enzyme of arachidonic acid synthesis, and enhanced plasma adrenocortical hormone levels. Inhibition of FADS2 in primary adrenal gland cell cultures abolished steroidogenesis, which was restored by arachidonic acid supplementation.ConclusionsOur data suggest that the FADS2 – arachidonic acid axis regulates adrenocortical hormone synthesis, while alterations in the content of arachidonoyl chains in the adrenal gland phopsholipidome could account for disturbed adrenocortical hormone production.HighlightsThe adrenal gland lipidome is remodeled in obesity.Arachidonoyl groups are abundant in the adrenal gland phospholipidome and increase in obesity.FADS2 is highly expressed in the adrenal gland and its expression is further increased in obesity.FADS2 inhibition blunts adrenocortical steroidogenesis in primary adrenal gland cell cultures, while arachidonic acid supplementation restores it.

Adrenal venous sampling: cosyntropin stimulation or not?

Notwithstanding the high prevalence of primary aldosteronism (PA), probably the most common form of secondary hypertension, the diagnosis of PA is often neglected or delayed, thus precluding target treatment, which is curative in many cases. For selection of the most appropriate treatment, a fundamental step is the distinction between a lateralized form, mainly aldosterone-producing adenoma (APA), and bilateral adrenocortical hyperplasia (BAH), also known as idiopathic hyperaldosteronism (IHA). To this aim all current guidelines recommend adrenal vein sampling (AVS), a technically challenging procedure that often fails, particularly in non-experienced hands. Cosyntropin (synthetic ACTH) is administered in the attempt to maximize adrenal cortisol secretion and avoid pulsatile adrenocortical hormone secretion in about 40% of the referral centres around the world. However, the Endocrine Society guidelines do not advise about the use or not of cosyntropin as stimulus during AVS, as there are arguments in favour and against its use. These arguments are presented in this debate article reflecting the views of groups that currently use and do not use cosyntropin.

Novel insights into glucocorticoid replacement therapy for pediatric and adult adrenal insufficiency

Adrenal insufficiency is defined as impaired adrenocortical hormone synthesis. According to its source, the deficit is classified as primary (adrenal steroidogenesis impairment), secondary (pituitary adrenocorticotropic hormone deficit) or tertiary (hypothalamic corticotropin-releasing hormone deficit). The management of adrenal insufficiency resides primarily in physiological replacement of glucocorticoid secretion. Standard glucocorticoid therapy is shrouded in several controversies. Along the difficulties arising from the inability to accurately replicate the pulsatile circadian cortisol rhythm, come the uncertainties of dose adjustment and treatment monitoring (absence of reliable biomarkers). Furthermore, side effects of inadequate replacement significantly hinder the quality of life of patients. Therefore, transition to circadian hydrocortisone therapy gains prominence. Recent therapeutic advancements consist of oral hydrocortisone modified-release compounds (immediate, delayed and sustained absorption formulations) or continuous subcutaneous hydrocortisone infusion. In addition to illustrating the current knowledge on conventional glucocorticoid regimens, this review outlines the latest research outcomes. We also describe the management of pediatric patients and suggest a novel strategy for glucocorticoid replacement therapy in adults.

Putative drivers of adrenocortical activity in captive African lesser bushbaby (Galago moholi)

In seasonal breeders, periods of reproductive activity often coincide with high levels of glucocorticoids. We studied seven male and seven female African lesser bushbabies (Galago moholi A. Smith, 1836) over two mating periods via noninvasive faecal hormone metabolite monitoring to investigate the relationship between reproductive and adrenocortical hormone activity. We used linear mixed-effect models to investigate the effect of physiological (endocrine) variables on faecal glucocorticoid metabolite concentrations. Our results indicate faecal androgen (males) and progestagen metabolite (females) concentrations as the variables best able to explain variability in faecal glucocorticoid metabolite concentrations. However, the models explained only a fraction (26% and 12%, respectively) of the observed variability and graphical analysis suggests a biologically relevant difference in faecal glucocorticoid metabolite concentrations between captive and free-ranging animals during nonreproductive periods. Thus, captivity may have affected glucocorticoid output in our focal animals, potentially weakening the expected relationship between reproductive activity and faecal glucocorticoid metabolite variability. Due to the ease of faecal and observational sample collection, a large number of studies monitoring adrenocortical activity in wildlife are conducted using only captive settings, with inferences unquestioned when applied to free-ranging scenarios. Our study cautions against this practice, as particular housing or management conditions may influence the pattern of adrenocortical activity.

Detection and Analysis of Autoantigens Targeted by Autoantibodies in Immunorelated Pancytopenia

Previously, we described a group of patients with hemocytopenia who did not conform to diagnostic criteria of known hematological and nonhematological diseases. Most patients responded well to adrenocortical hormone and/or high-dose intravenous immunoglobulin treatment, indicating that cytopenia might be mediated by autoantibodies. Autoantibodies were detected on the membrane of various bone marrow (BM) hemopoietic cells by bone marrow mononuclear-cell-Coombs test or flow cytometric analysis. Thus, the hemocytopenia was termed “Immunorelated Pancytopenia” (IRP) to distinguish it from other pancytopenias. Autoantigens in IRP were investigated by membrane protein extraction from BM hemopoietic cells and BM supernatant from IRP patients. Autoantibody IgG was detected in the BM supernatant of 75% of patients (15/20), which was significantly higher than that in aplastic anemia, myelodysplastic syndrome, or autoimmune hemolytic anemia patients (0%) and normal healthy controls (0%) (P<0.01). Autoantigens had approximate molecular weights of 25, 30, 47.5, 60, 65, 70, and 80 kDa, some of which were further identified by mass fingerprinting. This study identified that a G-protein-coupled receptor 156 variant and chain P, a crystal structure of the cytoplasmic domain of human erythrocyte band-3 protein, were autoantigens in IRP. Further studies are needed to confirm the antigenicity of these autoantigens.

Abstract 525: Nanomolar Ouabain Increases Na/Ca Exchanger-1 Expression and Enhances Ca2+ Signaling in Human Arterial Myocytes: A Mechanism That Links Salt to Increased Vascular Resistance?

The mechanisms by which excess dietary NaCl raises blood pressure (BP) in hypertension are unresolved. Much evidence indicates that endogenous ouabain (EO, an adrenocortical hormone and Na + pump blocker) plays a role. In rodents, arterial smooth muscle cell (ASMC) Na + pumps with an α2 catalytic subunit (ouabain EC 50 ≤1.0 nM) are crucial for some hypertension models, even though ≈80% of ASMC Na + pumps have an α1 subunit (ouabain EC 50 ≈5 μM). Human α1 Na + pumps, however, have high ouabain affinity (EC 50 ≈ 20 nM). Therefore, we studied the expression, distribution and function of Na + pump α subunit isoforms in ASMCs from surgically-recovered human artery segments. Immunoblots and immunocytochemistry reveal that human ASMCs (hASMCs) express α1 and α2 Na + pumps. As in rodents, α2, but not α1, pumps are confined to plasma membrane (PM) microdomains adjacent to sarcoplasmic reticulum, SR (identified with ER Tracker, an SR stain, and anti-SR Ca 2+ pump-2, SERCA2, antibodies). Na/Ca exchanger-1 (NCX1) and TRPC6 (component of receptor-operated channels, ROCs) co-localize with α2 in the PM microdomains. Incubation (72 hr) with 100 nM ouabain (blocks nearly all α1 and α2 pumps) was toxic to most cultured hASMCs, but 10 nM ouabain (blocks 90-95% of α2 and <<50% of α1 pumps) increased NCX1 and SERCA2 expression by 45±10% and 31±6%, respectively ( P <0.05; n =5 patients). Ca 2+ transients were measured with fura 2: The 72 hr, 10 nM ouabain pre-treatment increased 10 μM ATP-induced SR Ca 2+ release in 0Ca 2+ media by 27±8% ( P <0.05; n =3), and increased Ca 2+ influx when external Ca 2+ was restored (ATP still present) by 96±15% ( P <0.01; n =3 patients). This Ca 2+ influx was likely mediated primarily by ROCs and store-operated Ca 2+ channels. Thus, α2 Na + pumps, NCX1, ROCs, and the SR are structurally and functionally linked. Freshly-isolated myocytes from the arteries of several rat hypertension models display comparable protein expression and Ca 2+ signaling changes. We conclude that the same molecular mechanisms regulate long-term Ca 2+ homeostasis and signaling in human and rodent ASMCs. These ouabain/EO-modulated mechanisms underlie the ‘whole body autoregulation’ associated with increased vascular resistance and elevation of BP in human hypertension.