Intact Adrenals Research Articles

Значение тироксина в процессах взаимодействия кортикостероидов с белками плазмы крови на модели резистентности облучённых животных с аутотрансплантированными надпочечниками

The article is devoted to the study of the thyroxine effect on protein-steroid interaction in irradiated animals with autotransplanted adrenal glands. The relevance of the study is due to the need to study the radiobiological patterns of pituitary-thyroid regulation of protein-steroid interaction in acute radiation sickness in conditions of increased radioresistance of the body. The purpose of the work is to study the effect of thyroxine on the fractional composition of 11-hydroxycorticosteroids (11-OCS) and the binding capacity of corticosteroid binding globulin (CBG) in irradiated animals with autotransplanted adrenal glands. For experimental work 60 male rats weighing 200-220 g were used. Groups of animals with autotransplanted (experiment) and intact (control) adrenal glands were formed. Autotransplantation of the adrenal glands was performed according to the method of D. Ingle and G. Higgins. All animals were irradiated at a dose of 6.0 Gy. Animals in the experimental groups were administered 50 μg of thyroxine LD (Reanal, BP). Animals in the control groups were injected intraperitoneally an equal volume of physiological solution. To assess protein-steroid interactions, the fluorometric method, gel filtration method in the author's modification, a method for measuring the weight of the thymus were used. Conclusions were drawn about the effect of thyroxine on the protein-steroid interaction in radiation sickness using a model of resistance in irradiated animals with autotransplanted adrenal glands: 1) under the influence of thyroxine, the level of free 11-OCS in intact irradiated rats increases to a greater extent than the binding capacity of CBG; 2) administration of thyroxine to animals with autotransplanted adrenal glands causes an increase in the binding capacity of CBGs and a significant decrease in the concentration of free 11-OCS in the blood plasma; 3) the positive effect of thyroxine administration on increasing the weight of the thymus was manifested only in animals with autotransplanted adrenal glands; 4) an increase in the weight of the thymus in irradiated rats with autotransplanted adrenal glands under the influence of thyroxine is associated with a decrease in the content of unbound 11-OCS in the blood of animals.

Radiation of bilateral adrenal metastases is associated with a high risk of primary adrenal insufficiency.

Adrenal metastasis is the most common adrenal malignancy and can be bilateral in up to 43% of patients. Radiotherapy (RT) is one option available to treat adrenal metastases. The risk of primary adrenal insufficiency (PAI) after adrenal RT is unclear. Determine the incidence and the timeline of PAI in patients undergoing adrenal RT. Single-centre longitudinal retrospective cohort study of adult patients with adrenal metastases treated with RT between 2010 and 2021. Of 56 patients with adrenal metastases treated with adrenal RT, eight (14.3%) patients developed PAI at a median of 6.1 months (interquartile range [IQR]: 3.9-13.8) after RT All patients developing PAI had either unilateral RT in the setting of contralateral adrenalectomy or bilateral adrenal RT. Patients who developed PAI received a median RT dose of 50 Gy (IQR: 44-50 Gy), administered in a median of five fractions (IQR: 5-6). Treated metastases decreased in size and/or metabolic activity on positron emission tomography in seven patients (87.5%). Patients were initiated on hydrocortisone (median daily dose of 20 mg, IQR: 18-40) and fludrocortisone (median daily dose of 0.05 mg, IQR: 0.05-0.05 mg). At the end of the study period, five patients died, all due to extra-adrenal malignancy, at a median time of 19.7 months (IQR: 16-21.1 months) since RT and median time of 7.7 months (IQR: 2.9-12.5 months) since the diagnosis of PAI. Patients receiving unilateral adrenal RT with two intact adrenal glands have a low risk of PAI. Patients receiving bilateral adrenal RT have a high risk of PAI and require close monitoring.

Calcium Imaging and Amperometric Recording in Cultured Chromaffin Cells and Adrenal Slices from Normotensive, Wistar Kyoto Rats and Spontaneously Hypertensive Rats.

The spontaneously hypertensive rat (SHR) is a model widely used to investigate the causal mechanisms of essential hypertension. The enhanced catecholamine (CA) release reported in adrenal glands from adult SHRs raised considerable interest for its possible implication in the genesis of hypertension. The use of powerful techniques such as calcium imaging, electrophysiology, and single-cell amperometry to monitor in real time the key steps in CA secretion has allowed a better understanding of the role of chromaffin cells (CC) in the pathophysiology of hypertension, although several questions remain. Additionally, the implementation of these techniques in preparations in situ, such as the acute adrenal gland slice, which maintains the microenvironment, cell-to-cell communication, and anatomical structure similar to that of the intact adrenal gland, yields data that may have even greater physiological relevance. Here, we describe the procedures to measure the blood pressure of rats in a noninvasive manner, how to obtain primary cultures of adrenal chromaffin cells and acute adrenal slices, and how to perform amperometric recordings and intracellular calcium imaging in these preparations.

Online Detection of Catecholamine Release from the Perfused Rat Adrenal Gland.

Retrogradely perfused adrenal glands have historically served for establishing many of our current knowledge on the stimulus-secretion coupling process. Although the use of intact adrenals has largely been switched to isolated chromaffin cells, adrenal glands are still a very valuable tool to characterize physiological and pharmacological questions. Even more, this is an excellent preparation for studying the splanchnic nerve/chromaffin cell interaction. In this chapter, we will provide the ways to (i) perform retrograde perfusion of isolated rat adrenals, (ii) the method to apply electrical splanchnic nerve stimulation, and (iii) the preparation of adrenals to conduct online electrochemical detection of catecholamine release.

A case of solitary kidney with duplex collecting systems and renal vascular variants in an adult male cadaver

We describe a unique solitary kidney with duplex collecting system and vascular variation observed in an 86-year-old white male formaldehyde- and phenol-fixed cadaver during routine academic dissection. The left renal fossa was empty with an intact adrenal gland, and the right renal fossa contained a fused renal mass with apparent polarity between the superior and inferior regions and two renal pelves converging into a single ureter. There were three right renal arteries supplying the renal mass; the superior and middle arteries were noted to be postcaval and the inferior artery was precaval. There were also two right renal veins draining into the inferior vena cava and following a regional distribution with the superior vein draining the inferior portion of the renal mass. Despite generally being asymptomatic, the detection of renal anatomical variants is clinically important for appropriate patient management and surgical interventions.

Primary Adrenal Insufficiency Secondary to Chronic Posaconazole Use

Posaconazole (PSO) is commonly used in the treatment of invasive fungal infections. PSO-induced primary adrenal insufficiency (PAI) is rare, and we present what we think to be the third case report of its incidence. We want to bring awareness to this rare but significant side effect that can impact management and monitoring of patients on this medication. After clinical assessment, the patient was evaluated with diagnostic studies including measurements of cortisol, adrenocorticotropic hormone, renin activity, and aldosterone levels. Imaging studies such as abdominal computed tomography were also performed. A 65-year-old man with a history of hemophagocytic lymphohistiocytosis on a dexamethasone taper, complicated with mucormycosis on PSO presented to the emergency department with weakness, fatigue, decreased appetite, orthostatic hypotension, low morning cortisol (0.4 μg/dL), low adrenocorticotropic hormone (3.4 pg/mL), elevated plasma renin (16.7 ng/mL/hour), and low-normal aldosterone (1.7 ng/dL). Abdominal computed tomography imaging revealed bilaterally intact adrenal glands. A diagnosis of PSO-induced PAI was made. Fludrocortisone was initiated in addition to glucocorticoids with improvement of fatigue, appetite, blood pressure, and normalization of sodium and potassium. A month after discontinuing PSO, steroids and fludrocortisone were discontinued with measured morning cortisol of 13 μg/dL and an adrenocorticotropic hormone level of 53.9 pg/mL, both normal. Available data suggest that the adverse effect profile of PSO is more favorable than other triazoles. However, our case is the third report suggesting that PAI may be an underrecognized side effect. Awareness of this complication is particularly important in patients with severe or resistant fungal infections.

SUN-355 Computed Tomography Appearance of Adrenal Glands in Non-Adrenal Causes of Cushing's Syndrome

BACKGROUND: Incidental adrenal masses are noted on computed tomography (CT) imaging in 1-5% of the general population, with higher rates in older people. While most are benign, they may be hormonally functional and/or malignant. Characteristics such as size and radiodensity in Hounsfield units (HU) help to make these distinctions, as larger size and increased radiodensity (>20 HU) are associated with malignancy and/or pheochromocytoma. While adrenal causes of Cushing’s syndrome present with masses, limited data exists regarding adrenal morphology by CT in Cushing’s disease (CD) or Ectopic ACTH Syndrome (EAS). OBJECTIVE: To identify the incidence and characteristics of adrenal lesions in patients with non-adrenal causes of Cushing’s syndrome. METHODS: We retrospectively studied 80 patients with CD or EAS admitted under our protocols from 2008 to 2018. Inclusion required at least one intact adrenal gland and an abdominal or adrenal CT scan obtained before surgical cure. The radiology reports were reviewed for the presence of adrenal masses, simple adrenal hyperplasia and/or nodular adrenal hyperplasia. If available, the size and HU of masses were noted. Data are presented as median (range) or %. RESULTS: The age was 48.5 (17-81) years. 78 patients had histologically-proven CD (n=53, 44 women) or EAS (n=25, 13 women); 2 had occult presumed EAS (1 woman). The prevalence of discrete nodules was similar in EAS (15%) and CD (25%, P=0.3). • 13 CD patients had nodules (size 2.0 (0.9-5.0) cm). Of these, 5 were < 10 HU, 3 were > 10 but < 20 HU, and 1 was > 20 HU (not available, N/A=4). • 4 EAS patients had nodules ( size 1.0 (0.9- 1.3) cm). Of these, 2 were > 20 HU and 1 was < 10 HU (N/A=1). Biochemical testing for pheochromocytoma was negative when HU was >20. • Nearly all patients with discrete nodules had contralateral and/or adjacent adrenal hyperplasia. • The rate of nodularity was 15% in patients aged <50 and 28% in those aged ≥50 (P = 0.13). • All patients with a discrete nodule > 1.3 cm had CD. The presence of any nodule, regardless of size, had a positive predictive value for CD of 76% (95% CI: 54-90%). Of 63 patients without discrete nodules, 28 had simple hyperplasia (CD = 15, 28% vs EAS = 13, 48%, P=0.07). Another 12 patients, 8 with CD, had indiscrete nodular hyperplasia. One patient had normal sized glands. Data were N/A for 27 patients. CONCLUSION: The prevalence of adrenal nodules is greater in patients with CD and EAS than in the general population. Discrete nodules > 1.3 cm confirmed a diagnosis of CD, while simple hyperplasia was more likely in EAS. A larger cohort should be studied to determine if these trends are useful in the differential diagnosis of ACTH-dependent Cushing’s syndrome. The increased rate of nodularity in older patients may reflect pre-existing nodules, rather than an effect of Cushing’s syndrome per se. Finally, the reason(s) for differential formation of nodules in CD vs EAS requires further evaluation.

MON-359 Primary Adrenal Insufficiency Secondary to Chronic Use of Posoconazole: A Case Report

Cortisol attenuates inflammatory responses, contributes with glucose homeostasis, and enhances vascular smooth muscle tone augmenting blood pressure among other functions. The symptoms and signs of adrenal insufficiency (AI) depend upon acuity and degree of loss of the adrenal function, including whether mineralocorticoid production is preserved or not. A 65 years-old male with past medical history of mixed connective tissue disease developed 2 weeks of fever and was diagnosed with hemophagocytic lymphohistiocytosis for which he was placed on HLH-94 protocol (ectoposite and high dose pulse steroids). He was also found to have invasive murcomycosis initially treated with amphotericin and posacolonazole(PSO). Given the culture results, amphotericin was stopped and PSO 500mg daily was continued. The patient had a complicated hospital course and was discharged on 2mg of dexamethasone with a pertinent taper. He developed weakness and failure to thrive. His dexamethasone was increased to 3mg daily by his oncologist, and his PSO and chemotherapy was continued. Due to worsen fatigue and deconditioning the patient was brought to the Emergency Room. Upon arrival he was noticed to have persistent orthostatic hypotension despite intravenous fluids, hyponatremia and hyperkalemia (what is the potassium) suggestive of mineralocorticoid deficiency. Further endocrinology workup revealed plasma renin activity of 16.7ng/ml/hr (0.167-5.380) with a low aldosterone level of 1.6ng/dl (0.0-30). CT abdomen imaging showed intact adrenal glands bilaterally. Patient was diagnosed with PSO induced primary AI, he was placed on fludrocortisone with significant symptoms improvement and normalization of electrolytes and blood pressure. After a thorough literature review we found two case reports of iatrogenic Cushing in patients using Fluticasone and PSO, three cases of steroid induced secondary AI in patients treated with inhaled budesonide and PSO; and two cases of primary adrenal insufficiency in patients using PSO without steroids. PSO effects in the adrenal axis are rare, clinicians should be aware of their potential effects on the hypothalamic-pituitary-adrenal axis and pharmacologic interactions with steroids.

Abstract P276: (Pro)Renin Receptor-dependent Renal Generation of Aldosterone Contributes to ENaC Activation During Angiotensin II-induced Hypertension

(Pro)renin receptor (PRR) has emerged as a novel regulator of ENaC under various physiological and pathophysiological conditions including Ang II-induced hypertension. However, the mechanism for ENaC-activating action of PRR remains incompletely understood. The present study attempted to test renal-derived aldosterone (Aldo) as a potential mediator of PRR signaling in the setting of Ang II treatment. In normal Sprague-Dawley rats with intact adrenal glands, a 7-d minipump infusion of Ang II at 100 ng/kg/min induced a 3.2-fold increase in urinary Aldo excretion and a 1.8-fold increase in plasma Aldo, as assessed by ELISA. Following intramedullary delivery of a PRR decoy peptide PRO20 (120 μg/kg/d) (IM PRO20), Ang II-induced increases in urinary Aldo was reduced by 75% without affecting plasma Aldo, in parallel with attenuated hypertension (radiotelemetry-measured MAP on day 7: 132.6 ± 5.8 mmHg in Ang II+IMPRO20 vs. 157.1 ± 6.2 mmHg in Ang II). Following adrenalectomy (ADX), urinary Aldo was decreased from 9.3 ± 1.2 ng/24h to an unbeatable level under basal condition; it was elevated to 0.96 ± 0.05 ng/24h by Ang II and became undetectable again by IM PRO20, as assessed by mass spectrometry. Similar results were obtained by ELISA. In parallel, urinary Na+/K+ ratio in ADX rats was decreased by Ang II infusion and blunted by IM PRO20. Furthermore, Ang II infusion induced a 1.3-fold increase in urinary Aldo excretion and this increase was reduced by 60% in CD PRR KO mice, correlating to the changes in MAP. In cultured mpkCCD cells exposed to 10 nM prorenin, amiloride-sensitive transepithelial Na+ transport, measured by using epithelial volt-ohmmeter, was increased 2.1-fold at 6 h that sustained at 24 h, which was suppressed by 86% following treatment with the mineralocorticoid receptor antagonist eplerenone. Medium Aldo was increased by 2.6-fold following exposure to 10 nM prorenin for 24 h. Overall, these results suggest that activation of PRR results in local generation of Aldo that likely contributes to increased ENaC activity and thus hypertension during Ang II treatment.

Case report: ACTH-secreting pituitary carcinoma metastatic to the liver in a patient with a history of atypical pituitary adenoma and Cushing\u2019s disease

BackgroundPituitary carcinoma is a rare entity requiring the presence of metastasis to confirm its malignant potential. We report a case of pituitary carcinoma and discuss the diagnosis and management of this lesion in relation to the existing literature.Case presentationThe patient is a 51-year-old woman with Cushing’s disease and intact adrenal glands who was diagnosed with metastatic pituitary carcinoma to the liver, 29 months after initial resection of an ACTH-secreting primary atypical pituitary adenoma (APA). Prior to detection of this metastasis the patient underwent repeat resection and radiotherapy for residual cavernous sinus disease. The metastatic lesion was detected by interval surveillance of serum ACTH and 24-hour urine cortisol, which despite stable pituitary MRI, were significantly elevated. These abnormalities prompted a PET scan that demonstrated hypermetabolic liver parenchyma, which was suspicious for metastasis on abdominal MRI. An ultrasound-guided liver biopsy demonstrated nests of moderately-differentiated cells with intermediate-sized, monotonous nuclei, distinct nucleoli, and abundant basophilic cytoplasm, confirmed by immunohistochemistry to represent metastatic pituitary carcinoma. The liver lesion was subsequently successfully removed by wedge resection. One year later, the patient’s residual cavernous sinus disease grew markedly, and she was placed on dual-agent chemotherapy consisting of oral temozolomide and capecitabine, with stabilization of her intracranial disease to present, although liver metastases recurred.ConclusionsPituitary carcinoma is a rare entity impossible to recognize as a primary tumor because its diagnosis by definition requires the presence of metastasis. Maintaining awareness of the entity and its precursor lesion APA is essential for its accurate pathologic diagnosis and appropriate management.

Anti-inflammatory Effects of Diazepam on Different Models of Inflammation: Roles ofPeripheral Benzodiazepine Receptors and Genes for Corticosterone, Nitric Oxide andCytokines Biosynthesis

Background: It was reported that Peripheral Benzodiazepine Receptors (PBRs) agonists as diazepam possesses immunomodulatory and anti-inflammatory activities that suppress inflammation. Aim of the study: This study aims to investigate the anti-inflammatory effects of diazepam on the different inflammatory responses in the rats with exploring the possible underlying mechanisms. Methods and animals: 88 Albino rats used in acute and chronic inflammatory study of carrageenan–induced inflammatory paw edema of the rats (CIPE), and Freund’s adjuvant induced polyarthritis in rats respectively. Tested rat groups in both models received diazepam (I.P). Bilateral adrenalectomy was done in some rat groups of acute and chronic models as reference groups to diazepam treated groups with intact adrenals glands, and indomethacin was used as a reference anti-inflammatory agent in acute and chronic models of inflammation. The hind paw thickness and plasma Nitric Oxide (NOx) were assessed in each sub-groups of acute inflammatory response. The chronic inflammatory response was assessed by measuring the paw thickness, serum C-reactive protein, serum albumin and serum corticosterone of these arthritic rats. Results: Diazepam significantly reduced the increase in the paw thickness as well as NOx levels compared to other groups of acute study. Administration of diazepam for arthritic rats significantly decreased paw thickness, reduced increase in C-reactive protein, increased serum albumin, and increased serum corticosterone in comparison to administration of indomethacin to the arthritic rats. Diazepam had no any inhibitory anti-inflammatory actions on paw edema thickness, and on others measured serum biochemical when administrated to adrenalectomized rats in both acute and chronic inflammatory studies. Conclusion: Diazepam through enhancement of activity of genes responsible for synthesis of corticosterone via its stimulatory action on Peripheral Benzodiazepine Receptors (PBRs) in adrenal glands and modulating activity of immune cells could be of high pharmacological interest as a potential anti-inflammatory agent.

A Renal congenital Anomaly - unilateral extracalyceal Ectopic Right Kidney With Multiple Aberrant Renal Vessels

 Routine dissection of the abdomen of a 63 year old male cadaver in the Dept. of Anatomy Hi- tech medical college Rourkela., revealed the presence of a rudimentary ectopic right kidney fused to the lower pole of the left, with multiple aberrant renal arteries .The ureters were normal, the left kidney (upper) had a normal pelvis while the right (lower) had an extrarenal pelvis (extra calyx). The two ureters entered the bladder normally, Right side showed empty renal fossa with an intact adrenal gland. The possible embryological causes of this anomaly have been discussed here. Even though this type of condition can be presents as a silent renal anomaly (it can be undiagnosed throughout life and revealed through autopsy or dissection) the surgical implications are noteworthy,which too have been highlighted in this report.

RARE-15ACTH-SECRETING PITUITARY CARCINOMA METASTATIC TO THE LIVER IN A PATIENT WITH A HISTORY OF ATYPICAL PITUITARY ADENOMA AND CUSHING'S SYNDROME

Pituitary carcinoma is a rare entity requiring the presence of metastasis to confirm its malignant potential. Most examples secrete prolactin or adrenocorticotropic hormone (ACTH). Reported sites of metastasis include to the cerebral cortex, cerebellum, spinal cord, leptomeninges, eyes, heart, lung, lymph nodes, pancreas, liver, kidney, ovary, myometrium and bone. Liver metastasis is most common with prolactin-secreting tumors. In ACTH-secreting tumors it is frequently associated with Nelson's syndrome (rapid enlargement of a pituitary adenoma after bilateral adrenalectomy to palliate Cushing's syndrome). Here we report a case of an ACTH-secreting atypical pituitary adenoma metastasizing to the liver in a 51-year-old woman with Cushing's syndrome and intact adrenal glands 2.5 years after resection of the primary pituitary lesion with subsequent radiotherapy for residual cavernous sinus disease. Surveillance of ACTH and 24 hour urine cortisol levels revealed that they were significantly elevated to 142 pg/mL (normal range 10-60 pg/mL) and 541 µg/day (normal range 3.5-45 µg/day), respectively. These abnormalities prompted a PET scan which demonstrated a hypermetabolic liver lesion with a maximal SUV of 3.3, which was suspicious for metastasis on MRI. An ultrasound-guided liver biopsy demonstrated involvement by a moderately differentiated carcinoma consistent with a primary pituitary lesion. Nests of tumor cells showed a monotonous epithelioid appearance, abundant cytoplasm and small nucleoli. Immunostains for AE1/3, synaptophysin, and ACTH diffusely highlighted the lesional cells. This case thus represents an additional rare example of an ACTH-producing pituitary carcinoma metastatic to the liver in a patient with Cushing's syndrome and intact adrenal glands.

Pregnancy in a Patient With Adrenal Carcinoma Treated With Mitotane: A Case Report and Review of Literature

Adrenocortical carcinoma (ACC) affects patients in a broad age group, including young women. Mitotane, an adrenolytic agent, is the mainstay of treatment after surgical removal of the tumor. There is extreme paucity of information regarding the effect of mitotane on childbearing potential and pregnancy outcome. The aim of the study was to describe and discuss the case of an ACC patient who conceived while on mitotane treatment. Current literature is reviewed. A 33-year-old woman received mitotane treatment for 4 years due to metastatic ACC. Despite nearly therapeutic blood levels of the drug, the patient had regular menstruation and was able to conceive. Mitotane was stopped at gestation week 6. Although the drug continued to be detected in considerable amounts, the fetus developed normally, including morphologically intact adrenal glands. At gestation week 21, pregnancy was terminated due to ACC recurrence. Mitotane levels were undetectable in fetal cord blood and amniotic fluid. Our report suggests that mitotane, despite its action as an endocrine disruptor, does not affect normal gonadal function or an ability to conceive. The concern of placental transfer by this hydrophobic compound is not supported by our findings. However, we do not recommend drawing conclusions regarding the safety of mitotane in pregnancy, based on 1 or several case reports. Until more data are available, pregnancy should be avoided in women being treated with mitotane for ACC.

Intact Catecholamine Inputs to the Forebrain are Required for Appropriate Regulation of Corticotrophin‐Releasing Hormone and Vasopressin Gene Expression by Corticosterone in the Rat Paraventricular Nucleus

Corticotrophin-releasing hormone (CRH) neuroendocrine neurones in the paraventricular nucleus of the hypothalamus (PVH) drive adrenocorticotrophic hormone (ACTH) and thereby glucocorticoid release from pituitary corticotrophs and the adrenal cortex, respectively. Glucocorticoids suppress the ability of neuroendocrine corticotrophin-releasing hormone (CRH) neurones to synthesise and release ACTH secretogogues. Despite the importance of glucocorticoids as regulatory signals to CRH neurones in the extended time domain, how and where they act in this capacity is still not fully understood. Ascending catecholamine projections encode important cardiovascular, metabolic and other visceral information to the rat PVH and surrounding hypothalamus. These afferents have previously been implicated as targets for glucocorticoid action, including a role in the feedback regulation of PVH neuroendocrine neurones. To determine the contribution of these neurones to the long-term actions of corticosterone on CRH and vasopressin (AVP) gene expression in the PVH, we used an immunocytotoxin (a conjugate of the cytotoxin saporin and an antibody against dopamine-β-hydroxylase) that specifically ablates adrenergic and noradrenergic neurones. Lesions were administered to intact animals and to adrenalectomised animals with either no corticosterone or corticosterone replacement that provided levels above those required to normalise Crh expression. The ability of elevated levels of corticosterone to suppress Crh expression was abolished in animals lacking catecholaminergic innervation of the PVH. No effect was seen in the absence of corticosterone or in animals with intact adrenals. Furthermore, Avp expression, which is increased in CRH neurones following adrenalectomy, was suppressed in adrenalectomised catecholaminergic-lesioned animals. Interactions between corticosterone and catecholaminergic projections to the hypothalamus therefore make significant contributions to the regulation of Crh and Avp expression. However, the importance of catecholamine inputs is only apparent when circulating corticosterone concentrations are maintained either below or above those required to maintain the activity of the hypothalamic-pituitary-adrenal axis that is seen in intact animals.

Gene Profiling Reveals a Role for Stress Hormones in the Molecular and Behavioral Response to Food Restriction

Food restriction is known to enhance learning and motivation. The neural mechanisms underlying these responses likely involve alterations in gene expression in brain regions mediating the motivation to feed. Analysis of gene expression profiles in male C57BL/6J mice using whole-genome microarrays was completed in the medial prefrontal cortex, nucleus accumbens, ventral tegmental area, and the hypothalamus following a 5-day food restriction. Quantitative polymerase chain reaction was used to validate these findings and determine the time course of expression changes. Plasma levels of the stress hormone corticosterone (CORT) were measured by enzyme-linked immunosorbent assay. Expression changes were measured in adrenalectomized animals that underwent food restriction, as well as in animals receiving daily injections of CORT. Progressive ratio responding for food, a measure of motivated behavior, was assessed after CORT treatment in restricted and fed animals. Brief food restriction results in an upregulation of peripheral stress responsive genes in the mammalian brain. Time-course analysis demonstrated rapid and persistent expression changes in all four brain regions under study. Administration of CORT to nonrestricted animals was sufficient to induce a subset of the genes, and alterations in gene expression after food restriction were dependent on intact adrenal glands. CORT can increase the motivation to work for food only in the restricted state. These data demonstrate a central role for CORT in mediating both molecular and behavioral responses to food restriction. The stress hormone-induced alterations in gene expression described here may be relevant for both adaptive and pathological responses to stress.

Rostroventrolateral medullary neurons modulate glucose homeostasis in the rat

Several lines of evidence support the view that the premotor sympathetic input to the adrenal gland arises from the rostroventrolateral medulla (RVLM). The aim of this study was to determine whether RVLM neurons play a role in glucose homeostasis. We identified RVLM neurons that control epinephrine secretion by searching for medullospinal neurons that responded to neuroglucoprivation induced by systemic 2-deoxyglucose (2-DG) administration. We tested the effect of disinhibition of the RVLM on arterial blood pressure and plasma glucose concentration. RVLM medullospinal barosensitive neurons (n = 17) were either unaffected or slightly inhibited by 2-DG. In contrast, we found a group (n = 6) of spinally projecting neurons that were excited by 2-DG administration. These neurons were not barosensitive and had spinal conduction velocities in the unmyelinated range (<1 m/s). These neurons may mediate epinephrine secretion and participate in the counterregulatory responses to neuroglucoprivation. To test the hypothesis that activation of the RVLM leads to adrenomedullary activation and subsequent hyperglycemia, we applied the GABA(A) antagonist bicuculline to the RVLM and measured blood pressure, heart rate, and blood glucose in rats with intact adrenals or after bilateral adrenalectomy. Disinhibition of the RVLM resulted in hypertension, tachycardia, and hyperglycemia (4.9 ± 0.3 to 14.7 ± 0.9 mM, n = 5, P < 0.05). Adrenalectomy significantly reduced the hyperglycemic response but did not alter the cardiovascular responses. These data suggest that the RVLM is a key component of the neurocircuitry that is recruited in the counterregulatory response to hypoglycemia.

Nucleic acids, glycogen deposition and adrenal gland steroidogenesis in rats with a pituitary mammotropic tumor (MtTF4).

Rats which have an excess of ACTH, growth hormone and prolactin from a pituitary mammotropic tumor (MtT) show a marked growth of adrenal glands, liver, spleen and kidneys. Protein, DNA, RNA and cell numbers were increased in liver, adrenal glands, spleen and decreased in thymus of tumor bearing rats as compared to intact rats. MtT tumor decreased glycogen deposition in liver, adrenal glands, thymus and pituitary of MtT tumor bearing rats. Adrenal glands of intact and MtT tumor bearing rats incubated in vitro with 4-14C progesterone synthetized radioactive 11-deoxycorticosterone, corticosterone, 18-hydroxy-11-deoxycorticosterone, 18-hydroxy-corticosterone, 11-dehydro-corticosterone and aldosterone. Intact adrenals synthetized in vitro per mg tissues 60% higher amount of corticosteroids than adrenal glands of MtT tumor bearing rats. These results show that pituitary hormones from MtT tumor have multicellular effects. They increased nucleic acid content, cell multiplication and depressed steroid hydroxylation in adrenal mitochondria and glycogen deposition in some tissues of MtTF4 rats.

Differential expression and action of Toll-like receptors in human adrenocortical cells

During sepsis, an intact adrenal gland glucocorticoid stress response is critical for survival. Recently, we have shown that Toll-like receptors, particularly TLR2 and TLR4, are crucial in HPA axis regulation following inflammation, establishing a direct link between bacterial and viral ligands and the endocrine stress response. However, the exact role which TLRs play in adrenal homeostasis and malfunction is not yet sufficiently known. Using quantitative real-time PCR, confocal microscopy and the NF-kappaB reporter gene assay, we aimed to analyse both, expression and function of all relevant TLRs in the human adrenocortical cell line-NCI-H295R and adrenal cells in primary culture. Our results demonstrate a differential expression pattern of TLR1-9 in human adrenocortical cells as compared to immune cells and adrenocortical cancer cells. Consequently, activation of these cells by bacterial ligands leads to differential induction of cytokines including IL6, IL8 and TNF-alpha. Therefore, Toll-like receptors expression and function is a novel feature of the adrenal stress system contributing to adrenal tissue homeostasis, regeneration and tumorigenesis.

Torcetrapib‐induced blood pressure elevation is independent of CETP inhibition and is accompanied by increased circulating levels of aldosterone

Background and purpose:Inhibition of cholesteryl ester transfer protein (CETP) with torcetrapib in humans increases plasma high density lipoprotein (HDL) cholesterol levels but is associated with increased blood pressure. In a phase 3 clinical study, evaluating the effects of torcetrapib in atherosclerosis, there was an excess of deaths and adverse cardiovascular events in patients taking torcetrapib. The studies reported herein sought to evaluate off-target effects of torcetrapib.Experimental approach:Cardiovascular effects of the CETP inhibitors torcetrapib and anacetrapib were evaluated in animal models.Key results:Torcetrapib evoked an acute increase in blood pressure in all species evaluated whereas no increase was observed with anacetrapib. The pressor effect of torcetrapib was not diminished in the presence of adrenoceptor, angiotensin II or endothelin receptor antagonists. Torcetrapib did not have a contractile effect on vascular smooth muscle suggesting its effects in vivo are via the release of a secondary mediator. Treatment with torcetrapib was associated with an increase in plasma levels of aldosterone and corticosterone and, in vitro, was shown to release aldosterone from adrenocortical cells. Increased adrenal steroid levels were not observed with anacetrapib. Inhibition of adrenal steroid synthesis did not inhibit the pressor response to torcetrapib whereas adrenalectomy prevented the ability of torcetrapib to increase blood pressure in rats.Conclusions and implications:Torcetrapib evoked an acute increase in blood pressure and an acute increase in plasma adrenal steroids. The acute pressor response to torcetrapib was not mediated by adrenal steroids but was dependent on intact adrenal glands.