Elevated Serum ACTH Research Articles

ODP055 The methylation pattern of a unique Bilateral para-overian Adrenal Rest Tumor in a girl with Nicotinamide Nucleotide Transhydrogenase mutation

Abstract Background Patients with NNT (Nicotinamide Nucleotide Transhydrogenase) gene mutations, a rare cause of glucocorticoid and mineralocorticoid deficiency require hormone replacement therapy. Adrenal Rest Tumor (ART) in females, reported so far only in noncompliant patients with congenital adrenal hyperplasia and elevated ACTH levels, is very rare (<20 cases world-wide). This study characterizes the pathophysiology, the molecular ontogeny and methylation analysis of a unique ART in a female with adrenal failure due to the G200S mutation in NNT Clinical presentation and Method: A 15-year-old girl, with homozygous G200S NNT-mutation followed for adrenal insufficiency reappeared to follow-up with severe virilization and elevated serum testosterone (28.3 nmol/l) and ACTH (> 1500 pmol/l). Pelvic MRI and Ultrasound demonstrated one sided paraovarian round tumor with pathological vascularization. Laparoscopic exploration revealed bilateral para ovarian mesosalpinx masses involving the serosa of the Fallopian tube, (3 and 1 cm in diameter). The testosterone level normalized within one day after surgical removal of those masses (0.2 nmol/l). Results Histopathology demonstrated a pattern of adrenal rest tissue with strong intracellular positive staining for adrenal markers such as SF-1, calretinin, MART1, inhibin and the pituitary marker ACTH. The staining for ovarian characteristic markers such as PAX 8 was negative. Studying mRNA extracted from the tissue by RT-PCR revealed the positive Gene expression of Cyp17a1, Cyp21a2 and Mc2r cDNA but not Pomc suggesting adrenal but not pituitary origin of the tissue. We further profiled the epigenomic profile of several adrenal rest tumors from both ovarian and testes origins using the Infinium Methylation EPIC array. We characterized the adrenal-specific features by comparing the tumors from the two different originating sites to published methylation array data on healthy adrenal tissue. We further investigated cancer-specific methylation changes to identify activated cancer pathways, and used the methylation arrays to identify somatic copy number alterations. Finally, we analyzed the likely developmental origin of these tumors by comparing to published methylation array data of developmental and adult reproductive tissues. Conclusion This study exemplifies severe virilization that resulted from a unique and rare type of ART in ovarian related tissue that was caused by incompliance to treatment in a patient with NNT gene mutation. The laparoscopic surgical findings indicate that imaging techniques may be insufficient in identification of such rest tumors and call for laparoscopy when clinical findings are suggestive. An early detection of this tumor could preserve fertility. Using histopathology markers cDNA studies and epigenomic profiling by methylation studies, our study shows for the first time that female ART originates from adrenal cells. The growth of a functional androgen producing "tumor" indicates that functional NNT protein is NOT required for androgen synthesis in contrast to glucocorticoids and that a zona reticularis similar tissue in ART is responsive to ACTH stimulation. Presentation: No date and time listed

A Case of Ectopic Cushing’s Syndrome From a Large Cell Neuroendocrine Lung Tumor With Small Cell Component/Features

Abstract Background: Endogenous Cushing’s syndrome is uncommon in clinical practice. Survival of patients with new onset ectopic Cushing’s syndrome at relapse of small cell lung cancer has been found to be poor, with death occurring within an average of 27.3 days. Case Report: A 61-year-old African American male was seen by endocrinology service for inpatient evaluation of refractory hypokalemia of three months duration requiring recurrent potassium replacement with oral and intravenous therapy. He was inpatient for depressive symptoms and suicidal ideation. His admission lab showed hypokalemia of 2.7 mmol/L associated with elevated serum ACTH and serum cortisol. Past medical history is significant for unresectable large cell neuroendocrine neoplasm of the lung with small cell components/features diagnosed two years prior during lung cancer screening. He received chemotherapy with cisplatin/etoposide at diagnosis. He however had recurrence one year later with distant metastases. He was re-treated with cisplatin/etoposide in addition to palliative radiation therapy to painful bone met in his right hand. Three months prior to admission, imaging showed progression of the cancer with presence of new lesions in the liver for which he received one cycle of Nivolumab monotherapy. Social history was significant for 30-pack year smoking history. Physical exam findings were significant for: elevated blood pressure 167/96 mmHg, tachycardia of 107 bpm, oxygen saturation of 95% on 3-liters of intranasal oxygen, cachexia, absent buffalo hump, absent striae and decreased power in both lower limbs. Lab on supplementation showed serum potassium of 3.6, Serum magnesium of 2.0 and creatinine clearance greater than 60 Serum cortisol was 116.1 (5-25) mcg/dl and ACTH was 268.0 (9-52) pg/ml. An MRI by the referring team did not show a pituitary lesion. Patient was diagnosed with Cushing’s syndrome due to ectopic ACTH-production from a large cell neuroendocrine lung tumor with small cell component/features. Chart review showed his onset of hypokalemia occurred at the same time that imaging showed progression of the tumor three months prior. He was started on Ketoconazole and his cortisol level reduced to 14.0 within forty-eight hours with associated correction and stabilization of hypokalemia. The plan was to “block and replace” cortisol so that oncology could re-start chemotherapy. However, the patient developed acute respiratory decompensation requiring continuous BiPAP. Chest imaging showed progression of lung lesions with post obstructive pneumonia. The patient’s family opted for comfort measures and he was transferred to hospice care where he passed on ten days later. Conclusion: In the setting of lung cancer, new onset paraneoplastic Cushing’s syndrome may have prognostic implications. Clinicians should be aware of this, provide treatment for hypercortisolism and refer early to palliative care.

Severe Virilization in a Girl With the Homozygous G200SNicotinamide Nucleotide Transhydrogenase Mutation Is Surprisingly Caused by Rare Bilateral Para-Overian Adrenal Rest Tumors

Background: Patients with NNT (Nicotinamide Nucleotide Transhydrogenase) gene mutations, a rare cause of glucocorticoid and mineralocorticoid deficiency require hormone replacement therapy. Adrenal Rest Tumor (ART) in females is very rare (<20 cases world-wide) and was reported only in noncompliant patients with congenital adrenal hyperplasia having extremely elevated ACTH levels. This study characterizes the clinical characteristics, the pathophysiology and the molecular ontogeny of a unique ART in a female with adrenal failure due to the G200S mutation in NNT. Clinical presentation and Method: A 15-year-old girl, with homozygous G200S NNT-mutation that caused adrenal insufficiency reappeared to follow-up after several years with severe virilization and elevated serum testosterone (28.3 nmol/l) and ACTH (> 1500 pmol/l) levels. Pelvic MRI and Ultrasound demonstrated one sided para-ovarian round tumor with pathological vascularization. Laparoscopic exploration revealed bilateral para-ovarian mesosalpinx masses involving the serosa of the Fallopian tube (3 and 1 cm in diameter); the testosterone level normalized within one day after removal of those masses (0.2 nmol/l). Results: Histopathology demonstrated a pattern of adrenal rest tissue with strong intracellular positive staining for adrenal markers such as SF-1, calretinin, MART1, inhibin and the pituitary corticotroph marker-ACTH. The staining for ovarian characteristic markers such as PAX 8 was negative. Studying mRNA extracted from the tissue by RT-PCR revealed the presence of CYP17A1, CYP21A2 and MC2R (ACTH receptor) cDNA confirming typical adrenocortical transcriptional pattern in the tissue. cDNA of POMC was not detected suggesting that in spite of dense ACTH staining the tissue is not classically originated from pituitary corticotrophs. Methylome studies to further characterise the tissue are underway. Conclusion: This study exemplifies severe virilization that resulted from a unique and rare type of ART in ovarian related tissue that was caused by incompliance to treatment in a patient with NNT gene mutation. Given the ubiquitous expression of NNT and its reported pathophysiology as free radicals scavenger in all adrenocortical layers, it is surprising to have high ACTH induced severe virilization in spite of severe NNT dysfunction and adrenal insufficiency. This study may indicate timely testosterone screening in females with NNT mutation and when increased they should probably be laparoscopically surveyed for ART even when not detected by imaging. How NNT mutation damages mineralo and glucocorticoid secreting cells while androgen secreting cells are rescued is a theme for further studies.

MON-LB58 The Use of 11C Methionine PET CT In Localization of ACTH Dependent Cushing’s Disease

Background and objective: Hypercortisolism is the hall mark of ACTH Cushing’s syndrome, which is a benign ACTH secreting tumor resulting in high morbidity and mortality. The diagnosis is based on an elevated serum ACTH, elevated 24h urinary cortisol or a non-suppressible ACTH after dexamethasone suppression test. Confirmation of ACTH hypersecretion is followed by localization of the adenoma which can be pituitary in origin or peripheral. Dynamic MRI of the pituitary gland is the gold standard for diagnosis of pituitary tumors, and contrast enhanced CT scan is the gold standard for ectopic lesions which are usually lung tumors. The localization of the lesion is often a challenge because conventional MRI fail to show pituitary lesions and sometimes requiring inferior petrosal sinus sampling to confirm pituitary origin. Transsphenoidal surgery is the treatment of choice for Cushing’s disease, even without MRI evidence of pituitary tumors, if pituitary origin is confirmed by inferior petrosal sinus sampling. This causes increase in the incidence of treatment failure and complications. Thus, the diagnosis of Cushing’s disease urges exploring new diagnostic modalities. In our study we test the sensitivity of 11C methionine PET CT together with dynamic pituitary MRI in localization of ACTH dependent Cushing’s disease. Materials and methods This is an interventional, prospective study, forty-one subjects: newly diagnosed ACTH dependent Cushing’s Syndrome (n=29). (indicated by non-suppressible ACTH on dexamethasone suppression test) or persistent hypercortisolism following transsphenoidal surgery (n=12). 11C methionine PET CT was done in all cases in addition to dynamic pituitary MRI. All patients underwent 11 C-methionine PET-CT in addition to dynamic pituitary MRI This allowed us to determine whether suspected adenomas seen on structural imaging exhibited focal tracer uptake on functional imaging.Inclusion Criteria:• Aged 18 years old or over• Patient with a diagnosed Cushing’s disease confirmed by non-suppressible ACTH on dexamethasone suppression test.• Patient with persistent ACTH dependent Cushing’s disease following transsphenoidal surgery.• Patient not enrolled in other interventional studies.Exclusion Criteria:• Contraindication to MRI• Pregnant woman, breastfeeding RESULTS: Patients with newly diagnosed ACTH dependent Cushing: 24 out of 29 of the cases showed adenoma on dynamic MRI of the pituitary; 5 out of 29 cases failed to showed any lesions on dynamic MRI of the pituitary; Inferior petrosal sampling was done and confirmed pituitary origin in 4 out of 5 and 1 out of 5 was found to have ectopic ACTH secretion. In patients with persistent hypercortisolism following transsphenoidal surgery; 3 out of 12 of the cases showed adenoma on dynamic MRI of the pituitary and 7 out of 12 cases failed to showed any lesions on dynamic MRI of the pituitary and inferior petrosal sampling was done and confirmed pituitary origin in all 12 cases. All 41 cases underwent 11C methionine PET CT scan; 39 patients showed tracer uptake on 11c methionine PET CT scan in the pituitary area, 36 of which had unilateral asymmetrical tracer uptake. All 40 subjects with suspected pituitary lesions were confirmed to be of pituitary origin by histopathological examination of biopsies taken intraoperatively. CONCLUSIONS 11C methionine PET CT has proven to be of very high sensitivity in detecting ACTH secreting adenomas, further studies should be done on a larger scale as this modality can address the pitfalls in localization of ACTH secreting lesions.

Bilateral adrenal hemorrhage after hip arthroplasty: an initially misdiagnosed case

BackgroundBilateral adrenal hemorrhage (BAH) is a rare but potentially catastrophic condition. Its clinical manifestation is often non-specific and sometimes difficult to be diagnosed in time.Case summaryA 57-year-old woman, who presented with severe fatigue, nausea and vomiting after left hip arthroplasty due to her femoral neck fracture in a local hospital, was transferred to our medical center. Laboratory results revealed significant hyponatremia, low serum cortisol and elevated serum ACTH. Computed tomography (CT) showed a bilateral adrenal mass, measured 3.6 × 2.7 cm on the left and 3.4 × 2.3 cm on the right. Further magnetic resonance imaging (MRI) confirmed the diagnosis of BAH. The patient was prescribed with oral prednisolone acetate, 5 mg, tid, and her condition improved gradually. Nine months after, the patient was in good condition with 5 mg prednisolone acetate per day. CT revealed a clearly shrunken adrenal mass compared with 9 months ago.ConclusionsThis case illustrates the difficulty in making the diagnosis of BAH with atypical presentation. Such cases necessitate greater alertness on the part of the clinician and require rapid diagnosis and prompt glucocorticoid replacement for better clinical outcomes.

Paraneoplastic Cushing Syndrome: A Sign of Occult Malignancy

SESSION TITLE: Metastatic and Other Primary Lung Tumors SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Cushing Syndrome (CS) results from prolonged hypercortisolism. While often caused by iatrogenic administration of exogenous steroids or Cushing Disease, CS is also rarely caused by secretion of ACTH from ectopic sources, such as malignancies. Though rare - with ectopic ACTH secretion (EAS) accounting for only >15% of endogenous CS cases - diagnosis of CS can lead to earlier discovery of occult malignancy and increase potential for successful treatment. Clinicians therefore need a high degree of suspicion when faced with such presentations. CASE PRESENTATION: 57-yo man with CKD, CAD, HTN, DM and a long smoking history was admitted with respiratory failure due to CAP with dyspnea, weight gain, abdominal distention, and extremity weakness x 1 month. Physical exam showed reduced breath sounds over his right lower lung fields and abdominal obesity, but no Cushingoid appearance. He had marked refractory HTN. Labs showed profound hypokalemia with metabolic alkalosis, hypoxemia, hypercapnia and leukocytosis. CXR showed a right pleural effusion and basilar infiltrate. Elevated serum cortisol and ACTH levels helped diagnose CS. Abdominal CT showed no adrenal mass. Lab tests ruled out pheochromocytoma. A negative dexamethasone suppression test led to suspicion for EAS. CT Chest showed a mass with RML bronchial obstruction, mediastinal LAD and bilateral noncalcified lung nodules concerning for metastatic disease. While pleural fluid analysis showed a transudative effusion and microbiology was negative, cytology showed atypical cells suspicious for malignancy. Biopsy of the RML mass allowed for a unifying diagnosis of small cell carcinoma (SCLC) as the cause of the paraneoplastic CS. Chemotherapy was promptly started. DISCUSSION: Current standard practice for CS diagnostic work-up includes 8 mg dexamethasone suppression and CRH stimulation tests, inferior petrosal sinus sampling (IPPS), and imaging including CT, MRI, octreotide scans and venous sampling. In cases of EAS, the majority did not respond to CRH stimulation or dexamethasone suppression. IPPS was found most likely to identify the disease. Hypercortisol control treatments range from medications such as ketoconazole, metyrapone, or etomidate to surgical bilateral adrenalectomy. The highest rate of cure, up to 65%, came with the surgical removal of the ectopic ACTH-secreting neoplasm though recurrence was a possible complication. While cure in nonsurgical candidates is relatively rare, survival was common except in those cases of paraneoplastic CS caused by aggressive diseases. CONCLUSIONS: Though rare and difficult to recognize, Paraneoplastic CS may be the first sign of malignancy. While the source of EAS may be benign, it can be seen with SCLC, gastrinoma, medullary thyroid cancer and other such aggressive malignancies. Early identification may be lifesaving. Reference #1: Bertherat J. Cushing syndrome due to ectopic ACTH secretion. Orpha Net. 2012; ORPHA:99889 DISCLOSURE: The following authors have nothing to disclose: Vandana Pai, Kim Phung Nguyen, Jennifer Treece, Badar Siddiqui, Lisa McKinney-Smith No Product/Research Disclosure Information

HPA Axis Function as Biomarker for Atypical and Melancholic Depression

HPA Axis Function as Biomarker for Atypical and Melancholic Depression

Outcomes in pituitary surgery in Nelson's syndrome--therapeutic pitfalls.

Nelson's syndrome (NS) is a rare clinical syndrome caused by an enlarging, aggressive corticotroph pituitary adenoma that can occur following bilateral adrenalectomy performed in the treatment of refractory Cushing's disease (CD). Such tumours respond poorly to currently available therapeutic options, which include surgery, radiotherapy, pharmacotherapy, and chemotherapy. They are a challenging problem in neurosurgical practice. The aim of this work was to evaluate the early and long-term results of microsurgery in a single surgeon's series of patients with NS. During the period from January 2000 to December 2005, 10 patients with NS underwent surgery. The authors analysed surgical outcomes in the NS group of seven women and three men with the mean age of 47.99 years (range 39-66, SD ± 8.47 years). NS was diagnosed based on clinical signs and symptoms, especially hyperpigmentation of the skin, elevated serum ACTH levels, and pituitary tumour growth. Parasellar extension of the adenomas was assessed in both groups according to Knosp's and Hardy-Wilson classifications. Pituitary function and radiographs were evaluated in the early postoperative period, 30 days after the operation, and during follow-up. Histological examination was based on the WHO (2004) criteria. According to the criteria for Nelson's syndrome remission, five patients (50%) were cured. No perioperative mortality was reported. Three patients developed pituitary insufficiency and two patients developed diabetes insipidus. There was one case of postoperative cerebrospinal fluid leakage. One patient was diagnosed with pituitary carcinoma. Transsphenoidal microsurgical removal of pituitary adenomas is a safe and effective treatment of Nelson' syndrome.

Generalized glucocorticoid resistance caused by a novel two-nucleotide deletion in the hormone-binding domain of the glucocorticoid receptor gene NR3C1

Generalized glucocorticoid resistance is characterized by impaired cortisol signaling, resulting from mutations of the glucocorticoid receptor (GR) gene NR3C1. The objective of our study was to identify the causative mutation in a patient with clinical manifestations compatible with generalized glucocorticoid resistance and to determine the functional consequences of the mutation. The possible occurrence of NR3C1 mutations in a selected group of hypertensive subjects with low plasma renin and aldosterone levels was also explored. The proband, a male athlete, was diagnosed with hypertension associated with low plasma renin activity and low serum aldosterone concentration at the age of 27 years. Liddle's syndrome was suspected and the patient was treated with amiloride with initial success. Subsequent examinations revealed elevated serum cortisol and ACTH levels, with resistance to suppression with low doses of dexamethasone. After identification of an NR3C1 mutation in the proband, the available family members and 51 nonrelated hypertensive subjects with low plasma renin and aldosterone concentrations were also studied. A two-nucleotide deletion in exon 9α, predicted to cause a frameshift mutation (p.L773VfsX25) in the hormone-binding domain of the GR, was identified in the patient in a heterozygous form. Affected brother and father died of premature coronary heart disease. Functional studies in COS-1 cells showed that this mutation eliminates both ligand-binding and transactivation ability of the receptor. No pathogenic NR3C1 mutations were identified in 51 unrelated hypertensive patients with low plasma renin and aldosterone levels. We identified a novel frameshift mutation in NR3C1 as the cause of glucocorticoid resistance. The mutation eliminates the functional activity of the GR, as studied by in vitro experiments. Mutations in NR3C1 do not seem to be common causes for hypertension with low renin and aldosterone levels.

Bilateral Adrenalectomy for Refractory Cushing Disease: A Safe and Definitive Therapy

Refractory Cushing disease (CD) is associated with considerable morbidity and mortality. Bilateral adrenalectomy (BA) offers effective permanent treatment. Both open and laparoscopic approaches have been used, but longterm comparisons are few. We reviewed 40 consecutive BA for refractory CD from 1995 through 2007. Surgical results were evaluated. A Short Form-36 Quality-of-Life (QOL) survey was performed. Eighty-five percent (34 of 40) of patients were women, and median age was 41.9 years (range, 22.2 to 78.3 years). All had persistent CD after transsphenoidal operation (mean, 1.7; range, 1 to 3). Median followup was 5.0 years. Thirty-eight percent (15 of 40) of procedures were performed laparoscopically; 1 was converted to open. There were no operative or 30-day mortalities, and there was 1 90-day mortality. Morbidities occurred in 7 of 40 (18%) patients. Median length of stay was shorter in the laparoscopic group (4 versus 6 days; p < 0.001). All patients achieved clinical reversal of hypercortisolism, including the 5 (13%) with ectopic adrenal tissue. Elevated serum ACTH (> 200 ng/mL) was present during followup in 33% (13 of 40). A QOL survey demonstrated 86% of patients felt good to excellent compared with 1 year pre-BA. Chronic fatigue was present most or all of the time in 46%, and patients were below population norms on 7 of 8 Short Form-36 scales. No difference was evident in QOL between laparoscopic and open adrenalectomy. Our experience demonstrates excellent survival and clinical results, despite the inherent risk in patients with CD. There are persistent fatigue and QOL deficits that are not ameliorated by laparoscopic compared with open resection.

Addison's disease presenting as acute chest syndrome: Case report and review of literature

Addison's disease is due to primary adrenal failure. It is an uncommon condition with equal prevalence in both males and females. The onset of symptoms is gradual and manifestation is non specific, hence diagnosis is easily missed without a high index of suspicion. The medical records of a patient who presented with acute chest pain to the cardiac unit of the University of Port Harcourt Teaching Hospital were reviewed. A review of the literature using manual library and Medline search on Addison's disease was also done. A 48 years old male presented in our medical outpatient department with a three day history of sudden onset of severe precordial chest pain that started while playing football which was associated with nausea, vomiting and difficulty in breathing. After initial clinical evaluation a diagnosis of acute myocardial infarction and cardiac failure with a suspicion of background Addison's disease was made. Serial electrocardiography done over a two week period did not show evidence of myocardial infarction, but the patient had elevated serum ACTH and very low serum cortisol levels. An abdominal CT scan done two weeks after admission showed absence of the Adrenal glands bilaterally, confirming Addison's disease. He received treatment for cardiac failure, analgesics, prednisolone and a mineralocorticoid to which he responded satisfactorily and has remained healthy. He also received a six months course of antituberculous treatment empirically. Addison's disease is an uncommon endocrine disorder which can present insidiously in a non specific manner. Diagnosis requires a high index of suspicion.

Nelson’s syndrome after bilateral adrenalectomy for Cushing’s disease

Presentation and outcome of Nelson's syndrome after bilateral adrenalectomy is variable. Clinical records of 39 patients who underwent bilateral adrenalectomy for primary or recurrent Cushing's disease during a 15-year period were analyzed for frequency and evolution of Nelson's syndrome. The study included 32 females and 7 males with a mean age of 31 years; 20 patients had a hypophysectomy as the initial procedure, and 19 had an adrenalectomy. Of the group, 17 patients received prophylactic radiation therapy to the pituitary gland. A total of 11 patients, none of whom had received prophylactic radiation therapy, developed Nelson's syndrome (determined by skin hyperpigmentation, elevated serum ACTH levels, and enlargement of a previous pituitary tumor or development of a new tumor in patients with no previous pituitary abnormality) over a mean follow-up period of 53 months. Treatment for Nelson's syndrome included valproic acid, radiation therapy, and hypophysectomy as monotherapy or combined therapy. Of the remaining 28 patients, 10 (7 without prophylactic radio therapy) developed skin hyperpigmentation and increased ACTH levels without a tumor. Nelson's syndrome is a frequent complication after bilateral adrenalectomy in the absence of prophylactic radiotherapy (28%). The syndrome can be successfully controlled by medical treatment and or radiotherapy; patients rarely require hypophysectomy.

Large and Invasive Silent Corticotroph-cell Adenoma with Elevated Serum ACTH: A Case Report

Background A silent corticotroph-cell adenoma (SCCA) is defined as evidence of immunoreactive ACTH in tumor cells of a pituitary adenoma that is not associated with symptoms of Cushing’s disease. Most previous reports have discussed the etiology of this unique entity; however, the precise mechanisms of its “silence” are not clear yet. We discuss the pitfalls of endocrinological diagnosis and surgical management of SCCA. Methods A 63-year-old man, without the symptoms of Cushing’s disease, demonstrated elevated serum levels of ACTH, but normal levels of cortisol. ACTH was measured by newly developed immunoradiometric assays (IRMA), which are more specific for biologically active ACTH than conventional radioimmunoassay (RIA). The tumor was more than 3 cm in diameter and invaded both the cavernous sinus and the sphenoid sinus. Results Two different types of IRMAs revealed elevated serum ACTH levels. The tumor was removed successfully by staged operations. The high levels of serum ACTH were normalized after the second operation. Conclusion The cause of the silence of SCCA is not clear yet. The elevated serum ACTH levels in the present case were not attributable to “Big ACTH.” We suggest one possibility: the cause of the silence might be a minor variant of ACTH, detected by IRMA, leading to less biological activity of ACTH. This type of adenoma is invasive in nature and can potentially grow large because it is free of endocrinological symptoms. We emphasize the appropriate surgical strategy to normalize the serum levels of ACTH in case of SCCA.

Cellular nuclear binding and retention of glucocorticoids in rat lymphoid cells: effect of long-term adrenalectomy.

In the present study we have shown for the first time that lymphocytes from the spleen, thymus and mesenteric lymph nodes can specifically bind and retain 3H-dexamethasone in the nuclear fraction. The use of the specific corticosteroid receptor antagonists, RU28362 and RU38486, for the displacement of labeled dexamethasone revealed that binding was mainly of type-II glucocorticoids receptors. In lymphocytes obtained from mesenteric lymph nodes, binding was significantly higher than in cells obtained from spleen and thymus. Long-term adrenalectomy (up to 30 days), which markedly elevated serum ACTH, caused a time-dependent increase in binding in all lymphoid cells. No increase in binding was found in lymphocytes obtained from rats hypophysectomized for 15 days, in which neither serum ACTH nor corticosterone could be measured. These results suggest that the cellular nuclear binding in lymphocytes may be regulated by a pituitary factor.

Immunomodulatory ionophore copolymers, T150R1 and T130R2, induce corticotropin from anterior pituitary cells.

T150R1 is a synthetic copolymer with Na+ ionophore activity. We demonstrated previously that T150R1, when injected into mice, produces rapid thymic involution with depletion of cortical thymocytes. Elevated serum ACTH and corticosterone levels, as well as abrogation of the effects of T150R1 on the thymus by adrenalectomy and hypophysectomy, suggested a pituitary-mediated mechanism. In this work, we investigated the ability of T150R1, and of the related ionophore copolymer T130R2, to stimulate ACTH in vitro from the mouse anterior pituitary cell line AtT-20. Copolymer-induced ACTH release was dose-, time-, and temperature-dependent. Hormone induction peaked at 30 degrees C for T150R1 and 37 degrees C for T130R2. The temperature dependence of ACTH release paralleled that of ionophore activity measured in red blood cells, providing evidence that the ability to induce ACTH is related to the ionophore property of the copolymers. Peak ionophore activity and hormonal release occurred at the temperatures when the copolymers form partially soluble complexes which interact optimally with cell membranes. Cotreatment with exogenous phospholipase C inhibited the effects of T150R1, which suggests that the enzyme either blocks the insertion of T150R1 into the cell membrane or that the phospholipase C-induced increase in intracellular calcium inhibits the ionophore activity of T150R1. These data support an ionophore mechanism for copolymer-induced ACTH release in which changes in the physicochemical structure of the copolymers may affect their interaction with cell membranes. The data also suggest that direct stimulation of pituitary ACTH accounts for at least some of the in vivo immunomodulatory effects of T150R1.

Present status and future aspects of radioimmunoassay of tumor markers

BackgroundA silent corticotroph-cell adenoma (SCCA) is defined as evidence of immunoreactive ACTH in tumor cells of a pituitary adenoma that is not associated with symptoms of Cushing’s disease. Most previous reports have discussed the etiology of this unique entity; however, the precise mechanisms of its “silence” are not clear yet. We discuss the pitfalls of endocrinological diagnosis and surgical management of SCCA.MethodsA 63-year-old man, without the symptoms of Cushing’s disease, demonstrated elevated serum levels of ACTH, but normal levels of cortisol. ACTH was measured by newly developed immunoradiometric assays (IRMA), which are more specific for biologically active ACTH than conventional radioimmunoassay (RIA). The tumor was more than 3 cm in diameter and invaded both the cavernous sinus and the sphenoid sinus.ResultsTwo different types of IRMAs revealed elevated serum ACTH levels. The tumor was removed successfully by staged operations. The high levels of serum ACTH were normalized after the second operation.ConclusionThe cause of the silence of SCCA is not clear yet. The elevated serum ACTH levels in the present case were not attributable to “Big ACTH.” We suggest one possibility: the cause of the silence might be a minor variant of ACTH, detected by IRMA, leading to less biological activity of ACTH. This type of adenoma is invasive in nature and can potentially grow large because it is free of endocrinological symptoms. We emphasize the appropriate surgical strategy to normalize the serum levels of ACTH in case of SCCA.

ACTH and corticosterone secretion following indomethacin, in intact, adrenalectomized and dexamethasone-pretreated male rats.

The present study was designed to determine the role of glucocorticoids in the mediation of the stimulatory effect of indomethacin (IM) on the hypothalamo-hypophyseal-adrenal axis. Intact male rats were treated with a single injection of either dexamethasone (Dex; 20 micrograms/100 g body weight), IM (5 mg/100 g body weight), or IM + Dex or their respective vehicles. In Dex-treated rats, ACTH and corticosterone (CS) were significantly reduced over a period of 20 h as compared to the vehicle-treated group. As we have previously demonstrated, injection of IM markedly elevated serum ACTH and CS for at least 20 h. Administration of Dex 2 h prior to IM treatment delayed the stimulatory effect of IM for 5 h; subsequently, however, Dex was without effect. In adrenalectomized rats, ether stress elicited a marked rise in serum ACTH levels. On the contrary, IM was completely ineffective in these rats. These studies suggest that the mode of action of IM in causing hypersecretion of ACTH and CS is by interfering with the negative feedback effects of the glucocorticoids.

Corticotrophin and corticosterone secretory patterns following acute neurogenic stress, in intact and in variously hypothalamic deafferented male rats

Adult male rats, intact (N) or bearing complete (CHD), anterior (AHD), or posterior (PHD) hypothalamic deafferentations, were acutely exposed to either visual or audiogenic stimulation. At 2, 4, 10 or 30 min following the onset of stress exposure the animals were decapitated and trunk blood was collected for ACTH (RIA) and corticosterone (CS, CBG) determinations. Basal serum concentrations of both hormones were elevated in CHD and AHD, but not in PHD animals as compared to N animals. In N rats, exposure to both stresses resulted in elevated serum ACTH and CS concentrations, with the ACTH response to audiogenic but not visual stimulation being biphasic. In CHD animals, serum ACTH concentrations decreased, and those of CS were unchanged following stress exposure. While audiogenic stimulation caused elevation in serum levels of both hormones in AHD rats, the normal ACTH and CS response to visual stimulation were completely abolished by anterior hypothalamic deafferentation. In PHD animals, no ACTH response to either of the stress exposure was apparent; in spite of this, partial CS responses were elicited. These data thus describe the temporal aspects of the ACTH and CS secretory responses to different neurogenic stresses, and provide insight into the neural pathways mediating these responses.

Effects of systemically administered indomethacin on basal and stress-induced ACTH and corticosterone secretion in the male rat.

The effects of the prostaglandin (PG) synthetase inhibitor indomethacin (IM) on basal and stress-induced activity of the hypothalamo-hypophyseal-adrenal (HHA) axis were investigated. IM was systemically administered to adult male rats in a single injection (5 mg/100 g BW s.c.). The animals were sacrificed 24 h later, either under basal conditions, or following 30 min exposure to environmental temperature of 36 degrees C. Serum ACTH and corticosterone (CS) were determined by RIA and CBG, respectively, and hypothalamic and adenohypophyseal PGE2 and total PGE concentrations were estimated by RIA. IM treatment resulted in elevated basal levels of both hormones. Heat exposure led to elevated serum ACTH and CS concentrations in both vehicle- and IM-treated groups, with the ACTH heat response in IM-treated animals being greater than that observed in controls. PGE2, and PGE1 plus PGE2 concentrations were markedly reduced in both hypothalamic and adenohypophyseal tissues, following IM treatment. This study demonstrates that simultaneous reductions in hypothalamic and adenohypophyseal PG concentrations are compatible with hyperactivity of the HHA axis.

PRL and ACTH secretion following acute heat exposure, in intact and in hypothalamic deafferentated male rats

Adult male rats, intact or bearing complete, anterior or posterior hypothalamic deafferentiations (CHD, AHD, and PHD, respectively) were acutely exposed to environmental temperature of 36 °C, and serum PRL and ACTH concentrations were determined by RIA. In intact animals, heat exposure resulted in elevated serum PRL and ACTH levels. None of the deafferentations affected basal serum PRL concentrations, whereas those of ACTH were elevated in both CHD and AHD, but not in PHD groups, as compared to intact controls. The PRL heat response was completely absent in CHD, attenuated in AHD, and delayed in PHD animals, and the ACTH heat response was absent in all three groups. These results demonstrate (1) that acute exposure to elevated environmental temperature stimulates secretion of PRL and ACTH; (2) that this stimulation is carried out by diverse neural pathways; and, (3) that hypothalamic modulation of the secretion of PRL and ACTH is effected by independent mechanisms.