Adrenal Stimulation Research Articles

12325 Adrenocortical Carcinoma Masquerading As Pheochromocytoma In A Patient With Congenital Adrenal Hyperplasia

Abstract Disclosure: E.M. Niedzialkowska: None. A.A. Banka: None. Introduction: The development of adrenocortical carcinoma (ACC) in patients with congenital adrenal hyperplasia (CAH) is rare. The patients with CAH are at increased risk of adrenal tumors which is attributed to ACTH stimulation of adrenal gland if the disease is not appropriately treated. ACC cases mistaken for pheochromocytomas have been reported in the literature and are attributed to the variety of immunohistochemical markers expressed by the tumors. Case description:59 y.o female with salt-wasting CAH diagnosed at the age of 2 (21-hydroxylase deficiency) on hydrocortisone supplementation reported to the hospital due to episodes of sweating, tachycardia and hypertension. Work up revealed mildly elevated plasma normetanephrine 1 nmol/l (N <0.9), urine normetanephrine 1762 mcg (N<899), VMA 11.2 mcg/24hr (N 3.3-7.2). MRI of the abdomen revealed 2 left adrenal masses of 3.7 and 2.4 cm, right adrenal gland hyperplasia and low T1 and T2 enhancement. I-123 MIBG revealed increased activity and thickness of the right adrenal gland and no significant uptake on the left with nodular masses. The patient underwent left adrenalectomy with pathological report consistent with pheochromocytoma due to positive chromogranin and synaptophysin staining and moderate Ki activity. A year later follow up imaging showed an enhancing mass up to 7 cm at the suprarenal fossa invading the left kidney that was positive for nodular adrenocortical hyperplasia per pathology report. The patient continued to have elevated 17-OH- progesterone (2740 ng/l, N <51) despite compliance with her steroid therapy and suppressed ACTH. She underwent mass resection along with nephrectomy, splenectomy, partial colectomy and partial pancreatectomy. Pathology report was positive for adrenocortical carcinoma (positive chromogranin, synaptophysin, CAM 5.2, polycystic cytokeratin, Ki positive in greater than 10% of the tumor cells) with renal and regional lymph node invasion and colonic metastases. The patient was started on mitotane therapy but a year later PET scan was positive for liver and omental metastases and was subsequently started on carboplatin/etoposide followed by streptozocin/adriamycin with initial good response, however repeat PET a year afterwards showed progression of the liver lesions, metastases to omentum and metastatic lesion to calvarium and the patient expired soon afterwards. Discussion: CAH predisposes patients to adrenal tumors which is attributed to increased ACTH stimulation of the adrenal gland but ACC in this population is extremely rare. In very rare cases ACC can present clinically as pheochromocytoma with elevated catecholamine levels and positive synaptophysin and chromogranin staining which poses a clinical challenge. Both CAH and ACC can lead to increased androgen levels and ACTH levels can help to differentiate the origin of the hyperandrogenemia. Presentation: 6/2/2024

A randomized double blind study to evaluate the effect of nebulized dexmedetomidine on the haemodynamic response to laryngoscopy – Intubation and intubation conditions

: A cardiovascular stress response is frequently brought on by direct laryngoscopy and intubation. It is widely known that the sympathetic adrenal stimulation elicited by mechanical stimulation to the upper respiratory tract is what causes the haemodynamic response during laryngoscopy and intubation. The study's goal was to assess the impact of preoperative dexmedetomidine nebulization on the patient's hemodynamic response to laryngoscopy- intubation and the intubation conditions.: The American Society of Anaesthesiologists (ASA) I & II adult patients, of either gender, undergoing elective surgeries requiring tracheal intubation were randomized to receive nebulized dexmedetomidine (Group D) or 0.9% saline (Group P), 30 minutes prior to the induction of anesthesia. This study was conducted in the department of anesthesia and critical care at the Christian Medical College in Ludhiana. Following laryngoscopy, the patient's heart rate and non-invasive systolic and diastolic blood pressure will be monitored for 10 minutes. The intubation conditions were noted during laryngoscopy.Total 100 patients with 50 in each group were included. At the time of laryngoscopy and after the intubation 1 min, 3 min,5 min, 7min and 10 min there were significantly lower trend in increasing HR, SBP, DBP and RPP in dexmedetomidine group versus saline. The intubation score representing conditions for intubation was significantly better in the dexmedetomidine group (P=0.013) than the saline group. There was no significant side effect noted (p=1.000). There was significant reduction in intraoperative analgesic and sedative requirement observed in dexmedetomidine groupOur study concluded that the nebulized dexmedetomidine attenuated haemodynamic response to laryngoscopy- intubation and provided better intubation conditions without significant side effects. We advise using nebulized dexmedetomidine pre-operatively for a surgical procedure requiring general anesthesia in order to reduce the haemodynamic response to intubation and to facilitate intubation conditions without experiencing any severe adverse effects.

OR27-05 Two-pronged Mediation Of Adrenal Steroidogenesis By Oxytocin

Abstract Disclosure: U. Cheliadinova: None. G. Pevnev: None. V. Ryu: None. T. Frolinger: None. S.L. Sims: None. M. Ofer: None. F. Korkmaz: None. O. Barak: None. J. Gimenez Roig: None. F. Sultana: None. N. Kramskiy: None. S. Wizman: None. M. Orloff: None. T. Yuen: None. D. Lizneva: None. M. Zaidi: None. A. Gumerova: None. Stress–stimulated glucocorticoid release affects diverse biological processes, including pregnancy and childbirth. The controversy surrounding effects of OXT on stress prompted us to investigate its actions on adrenal cortical function in mice. RNAscope and immunohistochemistry provided unequivocal evidence for abundant OXT receptor (OXTR) expression in the adrenal cortex, predominantly in zona fasciculata and zona reticularis. Female mice displayed higher adrenal cortical Oxtr expression, more than a range of other tissues under study. Oxtr expression was also detected in the adenohypophysis solely in female mice, while both male and female mice expressed Oxtr in the pars intermedia of the hypophysis. Aging impressively attenuated Oxtr expression in female mice in both the adrenal gland and adenohypophysis. For loss–of–function studies, we generated tissue–specific Star-CreERT2/Oxtrfl/fl mice in which the Oxtr was deleted from steroidogenic tissues, namely adrenals and ovaries. Deletion was confirmed by RNAscope and immunohistochemistry. We found no difference in serum corticosterone between tamoxifen–induced and uninduced mice; however, the elevation of serum corticosterone upon ACTH stimulation or after four weeks of stress was attenuated in tamoxifen–induced mice. Bulk RNAseq of adrenals from tamoxifen–induced mice revealed the downregulation of key steroidogenic genes, namely Cyp17a1, Hsd3b3, Hsd17b2, Cyp3a41b, and Serpina6 (a corticosteroid–binding globulin). In gain–of–function studies, a single OXT injection led to a rise of serum ACTH in tamoxifen–induced mice, which was greater in magnitude than uninduced controls. However, after five days of OXT injections, corticosterone levels became elevated, whereas ACTH levels declined to baseline. This suggests that OXT acts directly on OXTRs on corticotropes to initiate a stress–like response, with a negative feedback loop that inhibits further ACTH secretion. Of note is that male mice did not display any difference between tamoxifen–induced and uninduced groups, consistent with their low hypophyseal Oxtr expression. In all, we describe a novel gender–specific two–pronged circuit through which OXT may precisely regulates the production of corticosterone from the adrenal cortex. In the first arm, OXT directly stimulates ACTH secretion through adenohypophysis OXTRs. In the second arm, OXT prevents excessive stress–induced adrenal stimulation by downregulating steroidogenic genes. Our discovery lays the foundation for the emergence of new physiology that may relate to a fundamental role for oxytocin in the stress response during procreation, notably, when levels are elevated during pregnancy and lactation. Presentation: Saturday, June 17, 2023

Analytical Validation and Assessment of Baseline Fecal Glucocorticoid Metabolites in Northern Sea Otters (Enhydra lutris kenyoni) in Human Care

Fecal glucocorticoid metabolites (FGMs) have been used as a non-invasive and indirect measurement of the complex stress response in a variety of species. Animals in facilities under managed care allow for the longitudinal study of FGMs in a controlled environment. Animal histories often include environmental, husbandry, and medical notes that can be matched to FGM concentrations to aid in the physiological validation of adrenal stimulation and response. The goal of this study was to demonstrate analytical validations using two enzyme-linked immunosorbent assays (EIA) to measure FGMs from northern sea otters (Enhydra lutris kenyoni) under human care (Seattle Aquarium, Seattle, WA, USA) and to determine baseline and stress response spike levels for individual sea otters. Individual variation was found among the four subjects in the study with fecal baseline levels ranging from 20.2 to 83.7 ng/g for cortisol-immunoreactive metabolites and 52.3 to 102 ng/g for corticosterone-immunoreactive metabolites. As a retrospective study, 39 percent of hormone peaks were associated with notes and most FGM spikes were associated with veterinary procedures or days in which enrichment items were provided and produced an excitatory response. Monitoring baseline FGMs levels and events associated with hormone peak values may provide insight into effective husbandry management to improve the overall welfare of sea otters and other marine mammals.

Differences in the regulatory mechanism of blood flow in the orofacial area mediated by neural and humoral systems.

Marked blood flow (BF) changes mediated by the autonomic neural and humoral systems may be important for orofacial hemodynamics and functions. However, it remains questionable whether differences in the autonomic vasomotor responses mediated by neural and humoral systems exist in the orofacial area. This study examined whether there are differences in changes in the BF and vascular conductance (VC) between the masseter muscle and lower lip mediated by autonomic neural and humoral systems in urethane-anesthetized rats. Electrical stimulation of the central cut end of the lingual nerve elicited BF increases in the masseter (mainly cholinergic) and lower lip (mainly non-cholinergic), accompanied by an increase in arterial blood pressure (ABP), while cervical sympathetic trunk stimulation consistently decreased BF at both sites. The lingual nerve stimulation induced a biphasic change in the VC in the masseter, consisting of an initial decrease and a successive increase. This decrease in VC was positively correlated with changes in ABP and diminished by guanethidine. Cervical vagus nerve stimulation also induced BF increases at both sites; the increases were greater in the masseter than in the lower lip. Adrenal nerve stimulation and isoproterenol administration induced BF increases in the masseter but not in the lower lip. These results indicate that cholinergic parasympathetic-mediated hemodynamics evoked by trigeminal somatosensory inputs are closely related to ABP changes. The sympathetic nervous system, including the sympathoadrenal system and visceral inputs, may be more involved in hemodynamics in the muscles than in epithelial tissues in the orofacial area.

Probing Neuro-Endocrine Interactions Through Remote Magnetothermal Adrenal Stimulation.

Exposure to stressful or traumatic stimuli may alter hypothalamic-pituitary-adrenal (HPA) axis and sympathoadrenal-medullary (SAM) reactivity. This altered reactivity may be a component or cause of mental illnesses. Dissecting these mechanisms requires tools to reliably probe HPA and SAM function, particularly the adrenal component, with temporal precision. We previously demonstrated magnetic nanoparticle (MNP) technology to remotely trigger adrenal hormone release by activating thermally sensitive ion channels. Here, we applied adrenal magnetothermal stimulation to probe stress-induced HPA axis and SAM changes. MNP and control nanoparticles were injected into the adrenal glands of outbred rats subjected to a tone-shock conditioning/extinction/recall paradigm. We measured MNP-triggered adrenal release before and after conditioning through physiologic (heart rate) and serum (epinephrine, corticosterone) markers. Aversive conditioning altered adrenal function, reducing corticosterone and blunting heart rate increases post-conditioning. MNP-based organ stimulation provides a novel approach to probing the function of SAM, HPA, and other neuro-endocrine axes and could help elucidate changes across stress and disease models.

Impact of Clomiphene Citrate on the Steroid Profile in Dysmetabolic Men with Low Testosterone Levels.

Clomiphene citrate (CC) in male hypogonadism increases testosterone (T) and estrogen levels by stimulating pituitary gonadotropin release. Our group confirmed these hormonal changes in a randomized, cross-over, double-blind trial of CC versus placebo in addition to metformin, conducted in 21 obese dysmetabolic men with low T levels. However, we hypothesize that based on its mechanism of action, CC may directly or indirectly affect adrenal steroidogenesis. The aim of this sub-study was to better understand the changes in steroid levels and metabolism induced by CC treatment. We assessed 17α-hydroxypregnelone (17αOH-P5), dehydroepiandrosterone (DHEA), progesterone (P4), 17α-hydroxyprogesterone (17αOH-P4), androstenedione (A), T, dihydrotestosterone (DHT), estrone (E1), 17β-estradiol (E2), 11-deoxycortisol (11 S), cortisol (F), and cortisone (E) by LC-MS/MS, and corticosteroid binding globulin (CBG) by ELISA, before and after each treatment. In addition, free-F and steroid product/precursor ratios were calculated. We observed a significant change in serum levels induced by CC compared with placebo for 17αOH-P4, DHT, T, E2, E1, F, E, and CBG, but not free-F. In addition, compared to placebo, CC induced higher 17αOH-P4/P4, E2/E1, 17αOH-P4/17αOH-P5, A/17αOH-P4, T/A, E1/A, F/11 S, and F/E ratios. Therefore, besides the CC stimulating effect on testis steroidogenesis, our study showed increased F, E, but not free-F, levels, indicating changes in steroid metabolism rather than adrenal secretion stimulation. The steroid profiling also revealed the CC stimulation of the Δ5 rather than the Δ4 pathway, thus indicating considerable testicular involvement in the increased androgen secretion.

The Herbicide Atrazine Potentiates Angiotensin II-Induced Aldosterone Synthesis and Release From Adrenal Cells.

Atrazine is one of the most commonly used pre-emergence and early post-emergence herbicides in the world. We have shown previously that atrazine does not directly stimulate the pituitary or adrenal to trigger hormone release but acts centrally to activate a stress-like activation of the hypothalamic-pituitary-adrenal axis. In doing so, atrazine treatment has been shown to cause adrenal morphology changes characteristic of repeated stress. In this study, adrenals from atrazine treated and stressed animals were directly compared after 4 days of atrazine treatment or restraint stress. Both atrazine and stressed animals displayed reduced adrenocortical zona glomerulosa thickness and aldosterone synthase (CYP11B2) expression, indicative of repeated adrenal stimulation by adrenocorticotropic hormone. To determine if reduced CYP11B2 expression resulted in attenuated aldosterone synthesis, stressed and atrazine treated animals were challenged with angiotensin II (Ang II). As predicted, stressed animals produced less aldosterone compared to control animals when stimulated. However, atrazine treated animals had higher circulating aldosterone concentrations compared to both stressed and control groups. Ang II-induced aldosterone release was also potentiated in atrazine pretreated human adrenocortical carcinoma cells (H295R). Atrazine pretreated did not alter the expression of the rate limiting steroidogenic StAR protein or angiotensin II receptor 1. Atrazine treated animals also presented with higher basal blood pressure than vehicle treated control animals suggesting sustained elevations in circulating aldosterone levels. Our results demonstrate that treatment with the widely used herbicide, atrazine, directly increases stimulated production of aldosterone in adrenocortical cells independent of expression changes to rate limiting steroidogenic enzymes.

Adrenal cortex stimulation with hCG in spayed female dogs with Cushing's syndrome: Is the LH-dependent variant possible?

Background:The expression and overexpression of luteinizing hormone (LH) receptors in the canine adrenal gland cortex have been reported. Therefore, it was hypothesized that a LH-dependent form of Cushing’s syndrome (CS) could exist in dogs. Aim:To assess whether the adrenal gland post-ovariectomy (OVx) exhibits a greater response to adrenocorticotrophin (ACTH) stimulation; to evaluate whether the adrenal gland responds to human chorionic gonadotropin (hCG) stimulation by increasing the release of cortisol; and to consider whether hCG stimulus testing would be useful as a diagnosis for possible cases of LH-dependent CS.Methods:Cortisol concentrations were measured from healthy female dogs (n=16) at baseline and following ACTH stimulation before and 2 months after gonadectomy (OVx). Cortisol concentrations were also measured for female dogs with CS (n = 14) following administration of hCG (5000 IU). A post-hCG cortisol concentration greater than 140 nmol/l was used to define dogs with LH-dependent Cushing’s syndrome.Results:In normal female dogs, both pre- and post-stimulation cortisol concentrations increased following OVx (p = 0.002 and p = 0.0003, respectively). In female dogs with CS, cortisol concentrations increased following stimulation with hCG in 57% (8/14; p = 0.002). Age at the time of OVx was associated (p = 0.015) with the cortisol response to hCG [8 (5–9) years vs. 3.5 (2–6) years, p = 0.0013).Conclusion:Based on these results, an LH-dependent form of CS occurs in spayed female dogs, and that it is more likely to occur when female dogs are spayed later in life.

A comparative study of haemodynamic response during LMA supreme insertion versus endotracheal intubation in paralysed patients during general anaesthesia

Introduction: LMA Supreme is a device which has recently been gaining popularly as an aid to airway management. During ETT intubation induces reflex sympathetic adrenal stimulation which is associated with raised levels of plasma catecholamines. This raised catecholamines induce hypertension and tachycardia. These effects should be avoided in patients with hypertension, ischemic heart disease, stenotic valvular heart disease, and raised intracranial tension, LMA Supreme can be used to over come the sympathetic response.Materials and Methods: 80 patients of either sex, aged 18 to 50 yrs posted for elective surgeries. Randomized to 2 groups N=40 each. We recorded HR, SBP, DBP, MAP, ETCO2, SPO2 at 0, 1, 5, 10 min and post extubation after LMA Supreme insertion, ET tube intubation and ease of insertion, no of attempts and post operative complications.Results: LMA Supreme airway is a safe and effective mean of maintaining airway. Ease and the simplicity makes the device well tolerated and the pressure response is less than endotracheal intubation. In our study we have observed the ETT intubation had increased haemodynamic responses when compared with LMA-S insertion.Conclusion: LMA Supreme can be suitable alternative to ETT intubation in elective adult surgeries. LMA-S with its unique design will help to expand Anaesthesiologist efficiency in the management of patients.

SUN-206 A Rare Case of Untreated Congenital Adrenal Hyperplasia Leading to Gender Dysphoria and a Female to Male Transgender

Background: CAH is a common genetic disorder usually diagnosed in early childhood. However, when it is detected in adulthood, different approach and treatment strategies need to be undergone as their needs are generally different from those of children with CAH. Case presentation: A 49-year-old male with a past medical history of recurrent urinary tract infections was admitted to the hospital with sepsis and was treated with antibiotics. CT abdomen during admission showed an incidental finding of markedly enlarged bilateral adrenal hyperplasia with an 8x5.5x5.8 cm left adrenal mass, as well as two ovaries and a uterus. Upon further history, the patient said he knew that he was born with abnormal genitalia and had a prolonged stay in the hospital immediately after birth and had surgery of his genitals at the age of six months. He was always told by his family that he is a female, although he never felt it, and he continued to identify himself as a male throughout his life.He only had one menstrual period at the age of thirteen. He participates in sexual activities as a male but was never able to have a normal sex life. He also gave a history of salt cravings, where he consumes dry salt. He was not taking any home medications.On examination, the patient had a male voice, a beard, male body hair distribution, no breast. The genital exam revealed labia majora, no labia minora. The rest of his examination was unremarkable.Work up for CAH revealed normal range plasma metanephrines and DHEA. But ACTH, androstenedione, 17-OH progesterone were all elevated (90.4 pg/ml, 2737 ng/dl, and 24191 ng/dl respectively) and levels were all higher after Cosyntropin stimulation test. He was found to have primary adrenal insufficiency with a maximum cortisol level of 13.3 mcg/dl after the stimulation test.He was started on oral Hydrocortisone and was closely followed by endocrine after discharge where long-term treatment plans were discussed and our patient decided that he wants to continue his life as a male, and was evaluated by Urology as well as OBGYN for left adrenalectomy and hysterectomy with bilateral Salpingo-Oophorectomy that was successfully performed a month later. Pathology of his left adrenals showed adrenocortical hyperplasia without evidence of malignancy. Patient was educated about lifelong corticosteroid treatment and that he would need to start testosterone replacement therapy to keep his male characteristics. Conclusion: When children with CAH lose follow up and don’t receive treatment early in life, they can develop gender dysphoria, and their approach as adults become more challenging and it needs a multidisciplinary team to treat, address their needs and detect complications of prolonged adrenal stimulation. Additional research to the natural history and optimal interventions is needed to improve outcomes as these cases are not encountered frequently in clinical practice.

Exercise‐induced α‐ketoglutaric acid stimulates muscle hypertrophy and fat loss through OXGR1‐dependent adrenal activation

Beneficial effects of resistance exercise on metabolic health and particularly muscle hypertrophy and fat loss are well established, but the underlying chemical and physiological mechanisms are not fully understood. Here, we identified a myometabolite‐mediated metabolic pathway that is essential for the beneficial metabolic effects of resistance exercise in mice. We showed that substantial accumulation of the tricarboxylic acid cycle intermediate α‐ketoglutaric acid (AKG) is a metabolic signature of resistance exercise performance. Interestingly, human plasma AKG level is also negatively correlated with BMI. Pharmacological elevation of circulating AKG induces muscle hypertrophy, brown adipose tissue (BAT) thermogenesis, and white adipose tissue (WAT) lipolysis in vivo. We further found that AKG stimulates the adrenal release of adrenaline through 2‐oxoglutarate receptor 1 (OXGR1) expressed in adrenal glands. Finally, by using both loss‐of‐function and gain‐of‐function mouse models, we showed that OXGR1 is essential for AKG‐mediated exercise‐induced beneficial metabolic effects. These findings reveal an unappreciated mechanism for the salutary effects of resistance exercise, using AKG as a systemically derived molecule for adrenal stimulation of muscle hypertrophy and fat loss.

MON-345 Recovery of Adrenal Function Following Bilateral Adrenal Hemorrhage: Two Case Reports

Background: Spontaneous or traumatic bilateral adrenal hemorrhage is a rare but potentially life-threatening condition which usually results in permanent adrenal insufficiency requiring life-long glucocorticoid and mineralocorticoid replacement. We present two patients with bilateral adrenal hemorrhage who subsequently partially recovered adrenal function. Case 1: A 38-year-old male developed bilateral adrenal hemorrhage and insufficiency after a car accident. His morning cortisol at the time of diagnosis was 0.6 mcg/dl (reference range 4.3-22.4 for morning cortisol) and his ACTH was 595 pg/ml (normal 7-69). He was treated with hydrocortisone and fludrocortisone. Hydrocortisone was discontinued 6 months later when he was found to have a morning cortisol of 10.8 mcg/dl. Fludrocortisone was discontinued a few months later when he developed hypokalemia and hypertension. His ACTH initially remained elevated at >500 pg/ml; and he did not experience a rise in his cortisol concentration after stimulation with 250 mcg of Cosyntropin, suggesting maximal baseline adrenal stimulation. He remained off glucocorticoid and mineralocorticoid replacement but was prescribed stress glucocorticoid coverage. Over the subsequent five years, his ACTH progressively returned to the normal range with recent level of 60 pg/ml with a morning cortisol of 13.6 mcg/dl. Case 2: A 67-year-old male developed bilateral adrenal hemorrhage secondary to heparin induced thrombocytopenia and presented with acute primary adrenal insufficiency (morning cortisol and ACTH at time of diagnosis were 5.5 mcg/dl and 219 pg/ml respectively). He was treated with hydrocortisone and fludrocortisone for 8 months. As he reported feeling well even on days when he missed his medications, his adrenal function was retested and he had a morning cortisol of 7.5 mcg/dl, and an ACTH of 452 pg/ml, suggesting partial recovery of adrenal function. Since his morning cortisol is still below 10 mcg/dl, he remains on glucocorticoid and mineralocorticoid replacement at lower doses, but we plan periodic re-evaluation of his adrenal function. Discussion: Adrenal dysfunction secondary to adrenal hemorrhage is generally believed to be irreversible, necessitating life-long glucocorticoid and mineralocorticoid replacement, except for a few reports in the literature suggesting partial recovery in some patients. We present two such rare cases in whom partial recovery of adrenal function was demonstrated after bilateral adrenal hemorrhage. Both patients had an unequivocal initial diagnosis based upon laboratory and imaging studies. Hence periodic re-evaluation of adrenal function should be considered in patients with adrenal insufficiency secondary to adrenal hemorrhage.

Investigation of adrenal and thyroid gland dysfunction in dogs with ultrasonographic diagnosis of gallbladder mucocele formation.

Gallbladder mucocele formation is an emerging disease in dogs characterized by increased secretion of condensed granules of gel-forming mucin by the gallbladder epithelium and formation of an abnormally thick mucus that can culminate in obstruction of the bile duct or rupture of the gallbladder. The disease is associated with a high morbidity and mortality and its pathogenesis is unknown. Affected dogs have a significantly increased likelihood of concurrent diagnosis of hyperadrenocorticism, hypothyroidism, and hyperlipidemia. Whether these endocrinopathies represent coincidental primary disease processes that exacerbate gallbladder mucocele formation in predisposed dogs or reflect a concurrent disruption of endocrine and lipid metabolism is unclear. In this study, we investigated a hypothesis that dogs with gallbladder mucocele formation would have a high prevalence of occult and atypical abnormalities in adrenal cortical and thyroid gland function that would suggest the presence of endocrine disruption and provide deeper insight into disease pathogenesis. We performed a case-control study of dogs with and without ultrasonographic diagnosis of gallbladder mucocele formation and profiled adrenal cortical function using a quantitative mass spectrometry-based assay of serum adrenal-origin steroids before and after administration of synthetic cosyntropin. We simultaneously profiled serum thyroid hormone concentrations and evaluated iodine sufficiency by measurement of urine iodine:creatinine ratios (UICR). The studies were complemented by histological examination of archival thyroid tissue and measurements of thyroid gland organic iodine from dogs with gallbladder mucocele formation and control dogs. Dogs with gallbladder mucocele formation demonstrated an exaggerated cortisol response to adrenal stimulation with cosyntropin. A prevalence of 10% of dogs with gallbladder mucocele formation met laboratory-based criteria for suspect or definitive diagnosis of hyperadrenocorticism. A significantly greater number of dogs with gallbladder mucocele formation had basal serum dehydroepiandrosterone (DHEAS) increases compared to control dogs. A high percentage of dogs with gallbladder mucocele formation (26%) met laboratory-based criteria for diagnosis of hypothyroidism, but lacked detection of anti-thyroglobulin antibodies. Dogs with gallbladder mucocele formation had significantly higher UICRs than control dogs. Examination of thyroid tissue from an unrelated group of dogs with gallbladder mucocele formation did not demonstrate histological evidence of thyroiditis or significant differences in content of organic iodine. These findings suggest that dogs with gallbladder mucocele formation have a greater capacity for cortisol synthesis and pinpoint DHEAS elevations as a potential clue to the underlying pathogenesis of the disease. A high prevalence of thyroid dysfunction with absent evidence for autoimmune thyroiditis suggest a disrupted thyroid hormone metabolism in dogs with gallbladder mucocele formation although an influence of non-thyroidal illness cannot be excluded. High UICR in dogs with gallbladder mucocele formation is of undetermined significance, but of interest for further study.

ATP-binding cassette transporter G1 deficiency is associated with mild glucocorticoid insufficiency in mice

ObjectiveSince cholesterol is the sole precursor for glucocorticoid synthesis, it is hypothesized that genetic defects in proteins that impact the cellular cholesterol pool may underlie glucocorticoid insufficiency in humans. In the current study, we specifically focused on the cholesterol efflux mediator ATP-binding cassette transporter G1 (ABCG1) as gene candidate. MethodsThe adrenal transcriptional response to fasting stress was measured in wild-type mice to identify putative novel gene candidates. Subsequently, the adrenal glucocorticoid function was compared between ABCG1 knockout mice and wild-type controls. ResultsOvernight food deprivation induced a change in relative mRNA expression levels of cholesterol metabolism-related proteins previously linked to steroidogenesis, i.e. scavenger receptor class B type I (+149%; P < 0.001), LDL receptor (−70%; P < 0.001) and apolipoprotein E (−41%; P < 0.01). Strikingly, ABCG1 transcript levels were also markedly decreased (−61%; P < 0.05). In contrast to our hypothesis that decreasing cholesterol efflux would increase the adrenal cholesterol pool and enhance glucocorticoid output, ABCG1 knockout mice as compared to wild-type mice exhibited a reduced ability to secrete corticosterone in response to an ACTH challenge (two-way ANOVA: P < 0.001 for genotype) or fasting stress. As a result, glucocorticoid target gene expression levels in liver and hypothalamus were reduced and blood lymphocyte concentrations and spleen weights increased in ABCG1 knockout mice under fasting stress conditions. This was paralleled by a 48% reduction in adrenal cholesteryl ester stores and stimulation of adrenal NPC intracellular cholesterol transporter 2 (+37%; P < 0.05) and apolipoprotein E (+59%; P < 0.01) mRNA expression. ConclusionABCG1 deficiency is associated with mild glucocorticoid insufficiency in mice.

Adrenocortical Challenge Response and Genomic Analyses in Scottish Terriers With Increased Alkaline Phosphate Activity.

Scottish terriers (ST) frequently have increased serum alkaline phosphatase (ALP) of the steroid isoform. Many of these also have high serum concentrations of adrenal sex steroids. The study's objective was to determine the cause of increased sex steroids in ST with increased ALP. Adrenal gland suppression and stimulation were compared by low dose dexamethasone (LDDS), human chorionic gonadotropin (HCG) and adrenocorticotropic hormone (ACTH) response tests. Resting plasma pituitary hormones were measured. Steroidogenesis-related mRNA expression was evaluated in six ST with increased ALP, eight dogs of other breeds with pituitary-dependent hyperadrenocorticism (HAC), and seven normal dogs. The genome-wide association of single nucleotide polymorphisms (SNP) with ALP activity was evaluated in 168 ST. ALP (reference interval 8–70 U/L) was high in all ST (1,054 U/L) and HAC (985 U/L) dogs. All HAC dogs and 2/8 ST had increased cortisol post-ACTH administration. All ST and 2/7 Normal dogs had increased sex steroids post-ACTH. ST and Normal dogs had similar post-challenge adrenal steroid profiles following LDDS and HCG. Surprisingly, mRNA of hydroxysteroid 17-beta dehydrogenase 2 (HSD17B2) was lower in ST and Normal dogs than HAC. HSD17B2 facilities metabolism of sex steroids. A SNP region was identified on chromosome 5 in proximity to HSD17B2 that correlated with increased serum ALP. ST in this study with increased ALP had a normal pituitary-adrenal axis in relationship to glucocorticoids and luteinizing hormone. We speculate the identified SNP and HSD17B2 gene may have a role in the pathogenesis of elevated sex steroids and ALP in ST.

Monitoring dehydroepiandrosterone (DHEA) in the urine of Thoroughbred geldings for doping control purposes.

The use of testosterone and its pro-drugs, such as dehydroepiandrosterone (DHEA), is currently regulated in horseracing by the application of international testosterone thresholds. However, additional steroidomic approaches, such as steroid ratios, to distinguish overall adrenal stimulation from drug administrations and an equine biological passport for longitudinal steroid profiling of individual animals could be advantageous in equine doping testing. Thus, DHEA concentrations and related ratios (testosterone [T] to DHEA and DHEA to epitestosterone [E]) were assessed in the reference population by quantitative analysis of 200 post-race gelding urine samples using liquid chromatography-tandem mass spectrometry. DHEA concentrations ranged between 0.9 and 136.6ng/mL (mean 12.8ng/mL), T:DHEA ratios between 0.06 and 1.85 (mean 0.43), and DHEA:E ratios between 0.21 and 13.56 (mean 2.20). Based on the reference population statistical upper limits of 5.4 for T:DHEA ratio and 48.1 for DHEA:E ratio are proposed with a risk of 1 in 10 000 for a normal outlier exceeding the value. Analysis of post-administration urine samples collected following administrations of DHEA, Equi-Bolic® (a mix of DHEA and pregnenolone) and testosterone propionate to geldings showed that the upper limit for T:DHEA ratio was exceeded following testosterone propionate administration and DHEA:E ratio following DHEA administrations and thus these ratios could be used as additional biomarkers when determining the cause of an atypical testosterone concentration. Additionally, DHEA concentrations and ratios can be used as a starting point to establish reference ranges for an equine biological passport.

Development and Validation of an Enzyme Immunoassay for Fecal Dehydroepiandrosterone Sulfate in Japanese Macaques (Macaca fuscata)

Measuring hormonal profiles is important in monitoring stress, physical fitness, and reproductive status in primates. Noninvasive methods have been used to measure several steroid hormones in primates without causing them stress. However, few studies have used feces or urine to measure dehydroepiandrosterone sulfate (DHEAS), an important precursor of sex steroids that has been studied as a biomarker of aging, pregnancy, and stress in humans and nonhuman primates. We developed an enzyme immunoassay to detect DHEAS in the feces of Japanese macaques (Macaca fuscata). Our subjects included eight singly housed Japanese macaques. To validate the assay, we administrated oral DHEA to one male and one female macaque, collected their feces, and measured DHEAS levels over time. Given that DHEAS is related to gonadal steroids and the stress response, we also measured DHEAS concentrations in response to adrenal (adrenocorticotropic hormone [ACTH]) and gonadal (human chorionic gonadotropin [hCG]) stimulation. Our assay successfully detected DHEAS in Japanese macaque feces, and levels of DHEAS were associated with the amount of DHEA ingested. Parallelism and accuracy tests revealed that fecal extracts were reliable measures of DHEAS. Neither ACTH nor hCG challenge appeared to affect DHEAS levels. The method we describe is less expensive than that using the commercially available kits and is applicable to investigations involving aging, stress, and reproduction in Japanese macaques.

Male but not female zebra finches with high plasma corticosterone have lower survival

Abstract The glucocorticoid axis is essential for coping with predictable and unpredictable environmental variation. Despite this vital function, attempts to link individual variation in the glucocorticoid axis to survival have yielded mixed results, which may be due to endocrine variation caused by uncontrolled variation in environment and life‐history traits such as reproductive effort. We therefore studied the link between the glucocorticoid axis and long‐term survival using captive non‐breeding zebra finches. We quantified the relationship between survival over a three‐year period and plasma corticosterone concentrations: (1) baseline, (2) stress‐induced, (3) after induction of negative feedback via dexamethasone injection and (4) after maximal adrenal stimulation via adrenocorticotropin hormone injection. Only stress‐induced corticosterone predicted survival, with higher concentrations being associated with lower survival. However, this effect differed significantly between the sexes, being present only in males. Stress‐induced corticosterone concentration is the sum of baseline corticosterone and the corticosterone increase in response to the standardized stressor, and both components were similarly associated with male survival in a model that included both variables. This implies that baseline corticosterone itself also exerts an effect on male survival, but this was only revealed when the stress‐induced corticosterone increase was included in the model, presumably because this increased statistical power. Given that corticosterone concentrations are highly repeatable in our study population and independent of manipulated foraging conditions, these data suggest that endocrine stress reactivity may be a major component determining male life span, presumably also in wild populations. A plain language summary is available for this article.

BP.08.04] COSYNTROPIN INFUSION SIGNIFICANTLY INFLUENCES THE RESULTS OF ADRENAL VENOUS SAMPLING IN PATIENTS WITH PRIMARY ALDOSTERONISM.

Objective: Adrenal venous sampling (AVS) in primary aldosteronism (PA) enables to identify the patients with unilateral form of the disease who can profit from adrenalectomy. Based on the available evidence, it is not clear whether to perform AVS procedure at rest under physiological conditions or following adrenal stimulation by adrenocorticotropin analogue consyntropin. Because of this reason, we performed a study to compare the diagnostic value of both AVS protocols. Design and method: The patients enrolled in the study underwent AVS both at rest and during adrenal stimulation by continuous infusion of cosyntropin. AVS procedure was considered successful provided cortisol concentrations in both adrenal samples were at least three times higher compared to peripheral blood at rest, and at least five times higher during adrenal stimulation. Cortisol corrected aldosterone concentration (AC) in adrenal samples was used to compare the aldosterone secretion between both adrenals. Lateralization index (LI) was calculated as a ratio of AC (dominant adrenal) to AC (non-dominant adrenal). Abnormal lateralization of aldosterone secretion was defined by LI >2 and >4 for AVS performed without and with adrenal stimulation. The results of both protocols were compared in respect to the procedural success and the diagnosis of the lateralization of the aldosterone secretion. Results: The study enrolled 46 patients who underwent 51 AVS. Procedural success without adrenal stimulation was observed in 32 (70%), and in 42 (91%) with adrenal stimulation. Both AVS protocols were successful in 31 (67%) individuals. In these patients, the lateralization of aldosterone secretion without adrenal stimulation was noted in 24 (77%), and in 14 (45%) when the AVS was performed during adrenal stimulation. Conclusions: Adrenal stimulation by cosyntropin infusion increases the success rate of the AVS procedure but may mask the lateralization of aldosterone secretion in some patients.