Cyproheptadine-induced remission of Cushing's disease

Neurochemical Anatomy of Cushing's Syndrome

The neurochemical anatomy underlying Cushing's syndrome is examined for regional brain metabolism as well as neurotransmitter levels and receptor binding of biogenic amines and amino acids. Preliminary studies generally indicate that glucose uptake, blood flow, and activation on fMRI scans decreased in neocortical areas and increased in subcortical areas of patients with Cushing's syndrome or disease. Glucocorticoid-mediated increases in hippocampal metabolism occurred despite in vitro evidence of glucocorticoid-induced decreases in glucose uptake or consumption, indicating that in vivo increases are the result of indirect, compensatory, or preliminary responses. In animal studies, glucocorticoid administration decreased 5HT levels and 5HT1A receptor binding in several brain regions while adrenalectomy increased such binding. Region-specific effects were also obtained in regard to the dopaminergic system, with predominant actions of glucocorticoid-induced potentiation of reuptake blockers and releasing agents. More in-depth neuroanatomical analyses are warranted of these and amino acid-related neurotransmission.

New and emerging drug therapies for Cushing's disease

INTRODUCTION

Cushing's disease is a rare systemic and disabling disease due to oversecretion of adrenocorticotrophic hormone (ACTH) resulting in excess cortisol levels. Diagnosis and treatment are difficult; despite the availability of various pharmaceutical treatment options, there is an ongoing, unmet need for even more effective treatment.

AREAS COVERED

The present review aims at providing an overview of available drugs and presenting new developments. Focusing on the pituitary as a target, the review covers compounds targeting pituitary cell signaling or cell cycle control such as heat shock protein inhibitors (e.g. silibinin), histone deacetylase inhibitors (trichostatin A, vorinostat), kinase inhibitors (gefitinib, seliciclib), and others (such as triptolide, AT-101). Levoketoconazole and osilodrostat are in clinical testing and inhibit steroidogenesis. Blockade of ACTH receptor binding at the adrenal level is explained as a theoretical drug target. Inhibition of binding of the glucocorticoid receptor in the peripheral tissue plays a minor role due to its lack of biomonitoring options.

EXPERT OPINION

In our opinion, further research and drug development of pituitary-directed targets are necessary. Combination therapies may exert synergistic effects and allow for smaller and better tolerated doses, but more experience and data are needed to guide such treatment schemes.

MANAGEMENT OF ENDOCRINE DISEASE: Can we cure Cushing's disease? A personal view

One of today's challenges in endocrinology is the treatment of Cushing's disease: Although pituitary surgery has the potential to 'cure' the patient and restore a completely normal pituitary adrenal axis, there are immediate failures and late recurrences that will ultimately require alternate therapeutic approaches. Their high number is in direct correlation with their serious limitations and they all appear to be 'default options'. This 'personal view' tries to shed some light on the inescapable difficulties of the current treatments of Cushing's disease and to provide some optimistic view for the future where the pituitary adenoma should be the 'reasonable obsession' of a successful therapeutist.

Are Cushing's disease patients curable?

Treatment of Cushing's disease remains a challenge. Whereas pituitary surgery can "cure" the patient and restore a completely normal pituitary adrenal axis, there are immediate failures and late recurrences which ultimately require alternate therapeutic approaches. These are numerous, but so are their drawbacks, and all appear to be "default options". For the future, pituitary adenoma has to remain the "reasonable obsession" of efficient and optimistic therapists….

Serotonin, ATRX, and DAXX Expression in Pituitary Adenomas: Markers in the Differential Diagnosis of Neuroendocrine Tumors of the Sellar Region

Differential diagnosis based on morphology and immunohistochemistry between a clinically nonfunctioning pituitary neuroendocrine tumor (NET)/pituitary adenoma and a primary or secondary NET of nonpituitary origin in the sellar region may be difficult. Serotonin, a frequently expressed marker in the NETs, has not been systematically evaluated in pituitary NETs. Although mutations in ATRX or DAXX have been reported in a significant proportion of pancreatic NETs, the mutational status of ATRX and DAXX and their possible pathogenetic role in pituitary NETs are unknown. Facing a difficult diagnostic case of an invasive serotonin and adrenocorticotroph hormone immunoreactive NET in the sellar region, we explored the immunohistochemical expression of serotonin, ATRX, and DAXX in a large series of pituitary endocrine tumors of different types from 246 patients and in 2 corticotroph carcinomas. None of the pituitary tumors expressed serotonin, suggesting that serotonin immunoreactive sellar tumors represent primary or secondary NETs of nonpituitary origin. Normal expression of ATRX and DAXX in pituitary tumors suggests that ATRX and DAXX do not play a role in the pathogenesis of pituitary endocrine tumors that remain localized to the sellar and perisellar region. A lack of ATRX or DAXX in a sellar NET suggests a nonpituitary NET, probably of pancreatic origin. One of the 2 examined corticotroph carcinomas, however, demonstrated negative ATRX immunolabeling due to an ATRX gene mutation. Further studies on a larger cohort of pituitary carcinomas are needed to clarify whether ATRX mutations may contribute to the metastatic potential in a subset of pituitary NETs.

The Treatment of Cushing's Disease

Cushing's disease (CD), or pituitary-dependent Cushing's syndrome, is a severe endocrine disease caused by a corticotroph pituitary tumor and associated with increased morbidity and mortality. The first-line treatment for CD is pituitary surgery, which is followed by disease remission in around 78% and relapse in around 13% of patients during the 10-year period after surgery, so that nearly one third of patients experience in the long-term a failure of surgery and require an additional second-line treatment. Patients with persistent or recurrent CD require additional treatments, including pituitary radiotherapy, adrenal surgery, and/or medical therapy. Pituitary radiotherapy is effective in controlling cortisol excess in a large percentage of patients, but it is associated with a considerable risk of hypopituitarism. Adrenal surgery is followed by a rapid and definitive control of cortisol excess in nearly all patients, but it induces adrenal insufficiency. Medical therapy has recently acquired a more important role compared to the past, due to the recent employment of novel compounds able to control cortisol secretion or action. Currently, medical therapy is used as a presurgical treatment, particularly for severe disease; or as postsurgical treatment, in cases of failure or incomplete surgical tumor resection; or as bridging therapy before, during, and after radiotherapy while waiting for disease control; or, in selected cases, as primary therapy, mainly when surgery is not an option. The adrenal-directed drug ketoconazole is the most commonly used drug, mainly because of its rapid action, whereas the glucocorticoid receptor antagonist, mifepristone, is highly effective in controlling clinical comorbidities, mainly glucose intolerance, thus being a useful treatment for CD when it is associated with diabetes mellitus. Pituitary-directed drugs have the advantage of acting at the site responsible for CD, the pituitary tumor. Among this group of drugs, the dopamine agonist cabergoline and the somatostatin analog pasireotide result in disease remission in a consistent subgroup of patients with CD. Recently, pasireotide has been approved for the treatment of CD when surgery has failed or when surgery is not an option, and mifepristone has been approved for the treatment of Cushing's syndrome when associated with impairment of glucose metabolism in case of the lack of a surgical indication. Recent experience suggests that the combination of different drugs may be able to control cortisol excess in a great majority of patients with CD.

Current approaches to the pharmacological management of Cushing's disease

If treatment of Cushing's disease (CD) by surgery is not successful, medical therapy is often required. Long-term use of metyrapone is limited by hirsutism and hypertension and escape because of increased ACTH levels. Although ketoconazole can normalize cortisol levels in 50%, liver toxicity limits its use. Mitotane, an adrenolytic agent, has had minimal use for benign disease. Etomidate is useful when rapid reduction in cortisol levels is needed. Cabergoline can normalize cortisol levels in CD in about one-third of patients and is well tolerated. Pasireotide can normalize cortisol levels in CD in about 25% but causes worsening of glucose tolerance in most patients. Mifepristone, a blocker of cortisol receptors, improves clinical aspects of CD in most patients but cortisol and ACTH measurements do not reflect clinical activity and adrenal insufficiency, hypokalemia, and endometrial hyperplasia can occur. Combinations of drugs can be tried in patients resistant to monotherapy.

Treatment of Cushing's disease: a mechanistic update

Cushing's disease (CD) is characterized by an ACTH-producing anterior corticotrope pituitary adenoma. If hypothalamus-pituitary-adrenal (HPA) axis physiology is disrupted, ACTH secretion increases, which in turn stimulates adrenocortical steroidogenesis and cortisol production. Medical treatment plays an important role for patients with persistent disease after surgery, for those in whom surgery is not feasible, or while awaiting effects of radiation. Multiple drugs, with different mechanisms of action and variable efficacy and tolerability for controlling the deleterious effects of chronic glucocorticoid excess, are available. The molecular basis and clinical data for centrally acting drugs, adrenal steroidogenesis inhibitors, and glucocorticoid receptor antagonists are reviewed, as are potential novel molecules and future possible targets for CD treatment. Although progress has been made in the understanding of specific corticotrope adenoma receptor physiology and recent clinical studies have detected improved effects with a combined medical therapy approach, there is a clear need for a more efficacious and better-tolerated medical therapy for patients with CD. A better understanding of the molecular mechanisms in CD and of HPA axis physiology should advance the development of new drugs in the future.

Molecular basis of pharmacological therapy in Cushing's disease

Cushing's disease (CD) is a severe endocrine condition caused by an adrenocorticotropin (ACTH)-producing pituitary adenoma that chronically stimulates adrenocortical cortisol production and with potentially serious complications if not or inadequately treated. Active CD may produce a fourfold increase in mortality and is associated with significant morbidities. Moreover, excess mortality risk may persist even after CD treatment. Although predictors of risk in treated CD are not fully understood, the importance of early recognition and adequate treatment is well established. Surgery with resection of a pituitary adenoma is still the first line therapy, being successful in about 60-70 % of patients; however, recurrence within 2-4 years may often occur. When surgery fails, medical treatment can reduce cortisol production and ameliorate clinical manifestations while more definitive therapy becomes effective. Compounds that target hypothalamic-pituitary axis, glucocorticoid synthesis or adrenocortical function are currently used to control the deleterious effects of chronic glucocorticoid excess. In this review we describe and analyze the molecular basis of the drugs targeting the disease at central level, suppressing ACTH secretion, as well as at peripheral level, acting as adrenal inhibitors, or glucocorticoid receptor antagonists. Understanding of the underlying molecular mechanisms in CD and of glucocorticoid biology should promote the development of new targeted and more successful therapies in the future. Indeed, most of the drugs discussed have been tested in limited clinical trials, but there is potential therapeutic benefit in compounds with better specificity for the class of receptors expressed by ACTH-secreting tumors. However, long-term follow-up with management of persistent comorbidities is needed even after successful treatment of CD.

Medical suppression of hypercortisolemia in Cushing's syndrome with particular consideration of etomidate

Cushing's syndrome is associated with excessive cortisol secretion by the adrenal gland or ectopic tumours and may result in diabetes, hypertension, and life-threatening infections with high mortality rates especially in the case of surgical resection. Although surgical resection is the treatment of choice, patients may benefit from preceding medical therapy. This may especially be useful as an adjunctive approach in emergency settings, if patients cannot undergo surgery, if surgery or radiotherapy fails, or if the tumour recurs. Medical therapy can be categorized in three different groups-inhibition of steroidogenesis, suppression of adrenocorticotropic hormone, and antagonism of the glucocorticoid receptor. However, the majority of common drugs are not available for parenteral administration, which may evoke a management problem in emergency settings or in patients unable to tolerate oral medication. The carboxylated imidazole etomidate is a well known parenteral induction agent for general anaesthesia. Besides its hypnotic properties, etomidate also has α-adrenergic characteristics and inhibits the enzyme 11-deoxycortisol ß-hydroxylase, which catalyzes the final step of the conversion of cholesterol to cortisol. Adverse outcomes have been reported when used for sedation in septic or trauma patients probably by its interference with steroid homeostasis. However, its capability of inhibition of the 11-deoxycortisol ß-hydroxylase leads to suppression of cortisol secretion which has been demonstrated to be a useful tool in severe and complicated hypercortisolemia. Within this article, we review the data concerning different pharmacological approaches with particular consideration of etomidate in order to suppress steroidogenesis in patients with Cushing's syndrome.

Prolonged remission after long-term treatment with steroidogenesis inhibitors in Cushing's syndrome caused by ectopic ACTH secretion

Spontaneous remission is rare in ectopic ACTH syndrome (EAS). We describe four patients with presumed EAS in whom long-term treatment with steroidogenesis inhibitors was followed by prolonged remission of hypercortisolemia. Biochemical testing was consistent with EAS, but imaging failed to identify a tumor. Patients were treated with ketoconazole alone or with mitotane and/or metyrapone to control hypercortisolemia. Dexamethasone was added when a block and replace strategy was used. Treatment with steroidogenesis inhibitors for 3-10 years in these patients was followed by a prolonged period of remission (15-60 months). During remission, the first patient had an elevated ACTH, low cortisol and 24-h urinary free cortisol (UFC), and adrenal atrophy on computerized tomography scan during remission, suggesting a direct toxic effect on the adrenal glands. Cases 2 and 3 had normal to low ACTH levels and low-normal UFC, consistent with an effect at the level of the ectopic tumor. They did not have a history of cyclicity and case 3 has been in remission for ~5 years, making cyclic Cushing's syndrome less likely. Case 4, with a history of cyclic hypercortisolism, had normal to slightly elevated ACTH levels and low-normal UFC during remission. The most likely etiology of remission is cyclic production of ACTH by the ectopic tumor. Spontaneous and sustained remission of hypercortisolemia is possible in EAS after long-term treatment with steroidogenesis inhibitors; a drug holiday may be warranted during chronic therapy to evaluate this. The pathophysiology remains unclear but may involve several different mechanisms.

Effectiveness of cabergoline in monotherapy and combined with ketoconazole in the management of Cushing's disease

The expression of dopamine receptor subtypes has been reported in corticotroph adenomas, and this finding support the possibility for medical treatment of Cushing's disease (CD) with dopamine agonists when conventional treatment has failed. The aim of this study was to evaluate the effectiveness of cabergoline (at doses of up 3 mg/week), alone or combined with relatively low doses of ketoconazole (up to 400 mg/day), in 12 patients with CD unsuccessfully treated by transsphenoidal surgery. After 6 months of cabergoline therapy, normalization of 24 h urinary free cortisol (UFC) levels occurred in three patients (25%) at doses ranging from 2-3 mg/week, whereas reductions ranging from 15.0 to 48.4% were found in the remaining. The addition of ketonocazole to the nine patients without an adequate response to cabergoline was able to normalize UFC excretion in six patients (66.7%) at doses of 200 mg/day (three patients), 300 mg/day (two patients) and 400 mg/day (one patient). In the remaining patients UFC levels did not normalize but a significant reduction ranging from to 44.4 to 51.7% was achieved. In two of the six responsive patients to combination therapy, the weekly dose of cabergoline could be later reduced from 3 to 2 mg. Our findings demonstrated that cabergoline monotherapy was able to reverse hypercortisolism in 25% of patients with CD unsuccessfully treated by surgery. Moreover, the addition of relatively low doses of ketoconazole led to normalization of UFC in about two-thirds of patients not achieving a full response to cabergoline.

Drugs in the medical treatment of Cushing's syndrome

Cushing's syndrome is a complex endocrine condition with potential serious complications if untreated or inadequately treated. Transsphenoidal surgery with resection of a pituitary adenoma is successful in 75 - 80% of patients, but approximately 20 - 25% show persistence of Cushing's, and a similar proportion may experience recurrence within 2 - 4 years post-op. When surgery fails, medical treatment can temporarily suppress excessive cortisol production and ameliorate its clinical manifestations while more definitive therapy becomes effective. We describe pharmacological approaches to the treatment of Cushing's syndrome. Drugs used to suppress cortisol secretion are mostly inhibitors of steroidogenesis. Ketoconazole, fluconazole aminoglutethimide, metyrapone, mitotane and etomidate are in that category. Ketoconazole is in current use while other drugs, although mostly available in the past, continue to have a potential role either alone or in combination. Drugs that suppress adrenocorticotropic hormone (ACTH) secretion are less popular as standard treatment and include cyproheptadine, valproic acid, cabergoline, somatostatin analogs, PPAR-gamma agonists, vasopressin antagonists. Some of these drugs have been tested in limited clinical trials but there is potential therapeutic benefit in analogs with better specificity for the class of receptors present in ACTH-secreting tumors. A third category of drugs is glucocorticoid receptor antagonists. Mifepristone is currently being tested in clinical trials in patients with persistent or recurrent Cushing's disease and in patients with metastatic adrenal cortical carcinoma or ectopic ACTH syndrome not amenable to surgery. We also review replacement therapy after surgery and non-specific drugs to treat complications in patients with severe hypercortisol. The review provides a complete survey of the drugs used in the medical treatment of Cushing's, and new advances in the development of pituitary-active drugs as well as receptor blockers of glucocorticoid action. It also provides avenues for exploration of new drugs active on somatostatin, dopamine and vasopressin receptors. There are effective pharmacological agents capable of chronically reversing biochemical and clinical manifestations of hypercortisolemia in Cushing's syndrome but new drugs are needed with action at the pituitary level.

Childhood virilization and adrenal suppression after ingestion of methandienone and cyproheptadine

We report a combination of precocious pseudopuberty and adrenal insufficiency in a 4 year-old boy who had received an off-label 'appetite stimulant' syrup and excessive virilization in a 2 year-old girl who had received the same medication. Both patients presented with excessive virilization for a period of approximately 1-2 years. The syrup contains cyproheptadine and methandienone, a derivative of testosterone. Both cyproheptadine and methandienone were responsible for severe adrenal suppression in the boy. Methandienone undoubtedly caused precocious virilization in both children. Cessation of the syrup led to partial regression of virilization in both children and normalization of adrenal reserve function in the boy.

Pituitary-directed medical treatment of Cushing's disease

The treatment of Cushing's disease is very complex and represents a challenge for clinicians. Transphenoidal surgical excision of adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma remains the treatment of choice but, unfortunately, the rate of cure at long-term follow-up is suboptimal and recurrences are high, even in the hands of skilled neurosurgeons. Other treatment options, such as bilateral adrenalectomy and pituitary radiotherapy, are currently in use but no treatment has proven fully satisfactory during the lengthy progress of this chronic and devastating disease. Nelson's syndrome and hypopituitarism are of particular concern as affected patients need lifelong hormone-replacement therapy and have notably increased mortality. Although medical treatment represents a second-line treatment option in patients with Cushing's disease, so far pharmacological therapy has been considered a transient and palliative treatment. Many drugs have been employed: they may act at the hypothalamic-pituitary level, decreasing ACTH secretion; at the adrenal level, inhibiting cortisol synthesis (steroidogenesis inhibitors); or at the peripheral level by competing with cortisol (glucocorticoid receptor antagonists). Recently, there has been renewed interest in the medical therapy of Cushing's disease and pituitary-directed drugs include old compounds commercially available for other diseases, such as cabergoline, and new promising compounds, such as pasireotide (SOM230) or retinoic acid. This review focuses on the tumor-directed pharmacological approaches for the management of Cushing's disease based on the recent identification of possibile targets at a pituitary level.

Pituitary-targeted medical therapy of Cushing's disease

BACKGROUND

The goals of ideal medical therapy for Cushing's disease should be to target the aetiology of the disorder, as is the case for surgery, which is the current 'gold standard' treatment. However, no effective drug that directly and reliably targets the adrenocorticotropin-secreting pituitary adenoma has yet been found.

OBJECTIVE

To summarise pituitary-targeted medical treatment of Cushing's disease.

METHODS

Compounds with neuromodulatory properties and ligands of different nuclear hormone receptors involved in hypothalamo-pituitary regulation have been investigated.

RESULTS

The somatostatin analogue pasireotide and the dopamine agonist cabergoline, as well as their combination, show some therapeutic promise in the medical therapy of Cushing's disease. Other treatments such as retinoic acid analogues look promising and may be a possible option for further investigation. No other medical therapies seem to be reliably effective currently.

CONCLUSION

Since a percentage of patients treated with surgery are not cured, or improve and subsequently relapse, there is an urgent need for effective medical therapies for this disorder. At present, only cabergoline and pasireotide are under active investigation.

Pharmacological management of Cushing's syndrome: an update

The treatment of choice for Cushing's syndrome remains surgical. The role for medical therapy is twofold. Firstly it is used to control hypercortisolaemia prior to surgery to optimize patient's preoperative state and secondly, it is used where surgery has failed and radiotherapy has not taken effect. The main drugs used inhibit steroidogenesis and include metyrapone, ketoconazole, and mitotane. Drugs targeting the hypothalamic-pituitary axis have been investigated but their roles in clinical practice remain limited although PPAR-gamma agonist and somatostatin analogue som-230 (pasireotide) need further investigation. The only drug acting at the periphery targeting the glucocorticoid receptor remains Mifepristone (RU486). The management of Cushing syndrome may well involve combination therapy acting at different pathways of hypercortisolaemia but monitoring of therapy will remain a challenge.

Advances in medical treatment of Cushing's disease

It is well known that transphenoidal surgery is the first line of treatment for Cushing's disease (CD). In case of recurrence, pituitary irradiation or adrenalectomy are usually performed; however, the morbidity due to these procedures is not negligible. For this reason, there is still a strong need for medical therapy, although there are only a few controlled data on this field. A variety of compounds are invaluable complementary tools in the management of this serious condition for which no treatment has yet been proven fully satisfactory. Pharmacological treatment could be employed by using neuromodulatory drugs (i.e., serotonin antagonists, dopamine, and GABA agonists) active only in a few cases of hypothalamic-pituitary-dependent CD. New approaches at the pituitary tumor level involve the potential use of other compounds (e.g., PPAR-γ agonists and retinoic acid). Exciting news in treating CD includes the recent availability of new multiligand somatostatin analogues. This review focuses on the new potential pharmacologic approaches for the management of CD based on the recent identification of possible targets and/or pathogenetic mechanisms.

[Nelson's Syndrome: a case report]

The aim of this article is to present and discuss several aspects of the pathogenesis, the clinical, hormonal, and imaging diagnosis, and the treatment of Nelson's syndrome, based on a typical patient's report, in whom several therapeutic approaches were shown to be ineffective.

Periodic secretion of adrenocorticotropin in a patient with Cushing's disease manifested during pregnancy

We report the case of 19-year-old woman with cyclical Cushing's disease, in whom plasma adrenocorticotropin (ACTH) was secreted periodically after her first pregnancy. Since the 33rd week of pregnancy, hypertension and proteinuria became clinically remarkable. She gave normal birth at 36th week of pregnancy; however she continued to gain body weight even after delivery and developed typical Cushingoid features. Her ACTH secretion lacked normal daily fluctuation but exhibited periodic change during 1-year observation, showing 119 pg/ml, 34.6 pg/ml and 115 pg/ml at the 4th, 7th and 13th months after delivery. Plasma ACTH levels were increased by corticotropin releasing hormone and metyrapone, while low-dose dexamethasone suppressed cortisol secretion. Gel filtration analysis of the patient's plasma detected big ACTH molecules being eluted with a peak of authentic 1-39 ACTH. Cranial magnetic resonance imaging revealed a 1-cm pituitary mass in right cavernous sinus. The pituitary tumor was removed by transsphenoidal surgery at 13th month after delivery and was pathologically compatible with ACTH-producing pituitary adenoma by immunohistochemistry. This case includes clinically rare subsets of Cushing's syndrome showing periodic ACTH secretion and aberrant ACTH molecules.

Endocrinological effects of mirtazapine in healthy volunteers

OBJECTIVE

Unlike other antidepressants, mirtazapine does not inhibit the reuptake of norepinephrine or serotonin (5-HT) but acts as an antagonist at presynaptic alpha2-receptors and at postsynaptic 5-HT2, 5-HT3 and histamine H1-receptors. In the present investigation, the influence of acute oral administration of 15-mg mirtazapine on the cortisol (COR), adrenocorticotropin (ACTH), growth hormone (GH) and prolactin (PRL) secretion was examined in 12 healthy male subjects, compared to placebo.

METHODS

After insertion of an intravenous catheter, both the mean arterial blood pressure (MAP) and the heart rate were recorded and blood samples were drawn 1 h prior to the administration of mirtazapine or placebo (7:00 a.m.), at time of administration (8:00 a.m.) and during 5 h thereafter in periods of 30 min. Concentrations of COR, ACTH, GH and PRL were measured in each blood sample by double antibody radioimmunoassay and chemiluminescence immunoassay methods. The area under the curve (AUC; 0-300 min after mirtazapine or placebo administration) was used as parameter for the COR, ACTH, GH and PRL response. Furthermore, the urinary free cortisol excretion (UFC) was determined beginning at 8:00 a.m. (time of administration of placebo or mirtazapine) up to 8:00 a.m. the day after.

RESULTS

Two-sided t-tests for paired samples revealed significantly lower COR AUC, ACTH AUC, UFC and PRL AUC values after 15-mg mirtazapine compared to placebo, whereas no significant differences were found with respect to GH AUC, MAP and heart rate.

CONCLUSIONS

Since the acute inhibition of COR secretion in the healthy volunteers was paralleled by a simultaneous decrease of ACTH release, central mechanisms (e.g., inhibition of hypothalamic corticotropin releasing hormone (CRH) output) are suggested to be responsible for the inhibitory effects of mirtazapine on COR secretion. Our results are of particular interest in the light of the hypercortisolism observed in depressed patients and new pharmacological approaches such as CRH1 receptor antagonists.

Functional PPAR-gamma receptor is a novel therapeutic target for ACTH-secreting pituitary adenomas

Adrenocorticotrophic hormone (ACTH)-secreting pituitary tumors are associated with high morbidity due to excess glucocorticoid production. No suitable drug therapies are currently available, and surgical excision is not invariably curative. Here we demonstrate immunoreactive expression of the nuclear hormone receptor peroxisome proliferator-activated receptor-gamma (PPAR-gamma) exclusively in normal ACTH-secreting human anterior pituitary cells: PPAR-gamma was abundantly expressed in all of six human ACTH-secreting pituitary tumors studied. PPAR-gamma activators induced G0/G1 cell-cycle arrest and apoptosis and suppressed ACTH secretion in human and murine corticotroph tumor cells. Development of murine corticotroph tumors, generated by subcutaneous injection of ACTH-secreting AtT20 cells, was prevented in four of five mice treated with the thiazolidinedione compound rosiglitazone, and ACTH and corticosterone secretion was suppressed in all treated mice. Based on these findings, thiazolidinediones may be an effective therapy for Cushing disease

Residual symptoms in depression an emerging therapeutic concept

Cushing's syndrome is due to chronic glucocorticoid excess that may have various etiologies. The most common endogenous form is pituitary-dependent bilateral adrenal hyperplasia, which is termed Cushing's disease. Major depression occurs in more than half of the cases. The presence of depressive symptoms connotes severity of clinical presentation and, in patients with hypothalamic-pituitary forms, entails prognostic value. Medical treatment may be used while awaiting more definitive solutions for the illness by surgery. The inhibitors of steroid production (e.g., ketoconazole, metyrapone and aminoglutethimide), rather than antidepressant drugs, are generally successful in lifting depression as well as other disabling symptoms. Since central serotonergic regulation could have a role in the course of Cushing's disease, serotonin antagonists (e.g., cyproheptadine, ritanserin and ketanserin) have been employed. Findings related to the pharmacological response of depression in Cushing's disease were found to have implications for the pathophysiology of depression and the potential involvement of the hypothalamic-pituitary-adrenal axis (HPA axis) in resistance and tolerance to antidepressant drugs. The use of serotonergic drugs in Cushing's disease may yield important insights in the understanding of serotonergic regulation both in Cushing's disease and in the HPA axis in nonendocrine major depression.

Classic and Recent Etiologies of Cushing??s Syndrome

Endogenous Cushing's syndrome can result from excess adrenocorticotropic hormone (ACTH; corticotropin) production by a pituitary adenoma (Cushing's disease) or by ectopic tumors secreting ACTH or corticotro- pin-releasing hormone (CRH). ACTH-independent Cushing's syndrome is caused by adrenocortical tumors or hyperplasias. Initial diagnosis is performed using 24-hour urinary free cortisol, low-dose dexamethasone tests, salivary cortisol, or night-time plasma cortisol values. A dexamethasone CRH test can discriminate between Cushing's syndrome and pseudo-Cushing's syndrome. If ACTH is elevated, combinations of high-dose dexamethasone tests, CRH/desmopressin tests, and pituitary magnetic resonance imaging can indicate a pituitary source. Discrimination from an ectopic ACTH tumor often requires inferior petrosal sinus sampling to confirm the ACTH source. If ACTH is low, adrenal computed tomography scan will identify the adrenal lesion(s) implicated. Some cortisol-producing adrenal tumors or, more frequently, bilateral macronodular hyperplasias, are under the control of aberrant membrane hormone receptors, or altered activity of eutopic receptors. The initial therapy of choice for patients with Cushing's disease is the selective transsphenoidal removal of the corticotroph adenoma; this induces remission in approximately 80% of patients, but long-term relapse occurs in up to 30% of these cases. The choice of second-line therapy remains controversial. Repeat surgery can be successful when residual tumor is detectable on magnetic resonance imaging, but carries a high risk of hypopituitarism. Bilateral adrenalectomy may be a better choice in patients without visible residual tumors, particularly in women desiring fertility. Radiotherapy combined with ketoconazole or radiosurgery was recently found effective, but longer-term evaluation of hypopituitarism and brain function is required. Current studies do not support the systematic use of prophylactic radiotherapy after bilateral adrenalectomy to decrease the risk of Nelson's syndrome; however, as soon as the residual tumor progresses, surgery and radiotherapy should be initiated. Various drugs which inhibit steroid synthesis (ketoconazole, metyrapone, aminoglutethimide, mitotane) are often effective for rapidly controlling hypercortisolism either in preparation for surgery, after unsuccessful removal of the etiologic tumor, or while awaiting the full effect of radiotherapy or more definitive therapy. Surgery is usually the treatment of choice for removal of cortisol-secreting adrenal tumors or ectopic ACTH/CRH-secreting tumors. The identification of aberrant adrenal receptors has recently allowed normalization of cortisol secretion by specific ligand receptor antagonists in limited cases of Cushing's syndrome secondary to bilateral macronodular adrenal hyperplasia. The long-term follow-up of patients treated for Cushing's syndrome should include the adequate replacement of glucocorticoids and other hormones, treatment of osteoporosis, and detection of long-term relapse of Cushing's syndrome.

Medical therapy of Cushing's disease

Surgical excision of an ACTH-producing pituitary tumor is the optimal therapy for Cushing's disease. However, medical therapy may have either a primary or adjunctive role if the patient cannot safely undergo surgery, if surgery fails, or if the tumor recurs. When medication is the only therapy, a major disadvantage is the need for lifelong therapy; in general, recurrence follows discontinuation of treatment. These compounds work through three broad mechanisms of action. "Neuromodulatory" compounds modulate corticotropin (ACTH) release from a pituitary tumor, steroidogenesis inhibitors reduce cortisol levels by adrenolytic activity and/or direct enzymatic inhibition and glucocorticoid antagonists block cortisol action at its receptor. In general, neuromodulatory compounds (bromocriptine, cyproheptidine, somatostatin and valproic acid) are not very effective agents for Cushing's disease. Treatment with a glucocorticoid antagonist and radiation therapy has been reported on a single patient only. Steroidogenesis inhibitors, including mitotane, metyrapone, ketoconazole, and aminoglutethimide, are the agents of choice for medical therapy of Cushing's disease. In general, ketoconazole is the best tolerated of these agents and is effective as monotherapy in about 70% of patients. Mitotane and metyrapone may be effective as single agents, while aminoglutethimide generally must be given in combination. The intravenously-administered etomidate may used when patients cannot take medications by mouth.

Behavioral, biochemical and neuroendocrine responses to amphetamine in normal twins and 'well-state' bipolar patients

An i.v. injection of dextroamphetamine (0.3 mgm/kg) was given to 13 pairs of normal monozygotic twins, three pairs of normal dizygotic twins and 11 patients with bipolar affective disorder in remission and off medications. Behavioral excitation in response to amphetamine was highly correlated in monozygotic twins; it was predicted by the baseline variables of high plasma MHPG, low serum prolactin and low pulse; it correlated with a rise in cortisol; and it was not correlated with plasma amphetamine level. Pre-infusion baseline MHPG and growth hormone and prolactin responses to amphetamine also were concordant in twins. Plasma amphetamine level, pulse and blood pressure and cortisol responses were not concordant, suggesting significant environmental influences. Haloperidol pretreatment in one pair of twins abolished the excitation response but did not reduce increases in cortisol and growth hormone. This suggests a role for dopamine in the excitation response but predominant serotonergic and noradrenergic mediation of the hormonal responses. None of the responses or baseline measures distinguished patients from controls. Thus, no consistently altered sensitivity to monoaminergic stimulation by amphetamine in bipolar affective disorder was demonstrated in this study. This is one of the first reports of familial (possibly genetic) variation in a psychostimulant drug response in man. The responses identified as concordant may be useful in characterizing other pathologic conditions.

Effect of the serotonin antagonists ritanserin and ketanserin in Cushing's disease

Central serotonergic regulation could have a role in the course of pituitary-dependent Cushing's disease. We studied the effects of ritanserin and ketanserin, two related selective 5HT2 receptor antagonists, in 11 patients with Cushing's disease. Treatment lasted from 1 month to 1 year (up to 4 years in one patient). Daily doses were 10-15 mg for ritanserin, and 40-80 mg for ketanserin. Since the two drugs share the same mechanism of action and no qualitative or quantitative differences in response to their administration were observed, the results were pooled together. Patients were assessed by clinical and hormonal evaluation. Urinary cortisol and ACTH were considered the parameters of interest. Short-term response: after 1 month, there was a significant decrease of urinary cortisol from 781 (160) to 331 (215) nmol/d (P < 0.02) while ACTH was 9.8 (1.5) pmol/L baseline and again 8.8 (2.2) pmol/L at 1 month (P = NS). For 9 patients, hormonal parameters were available after 1 week of treatment. In this case, also ACTH levels were significantly decreased (from 9.6 (1.7) to 5.2 (1.3) pmol/L; P < 0.01) together with urinary cortisol (from 781 (194) to 372 (165) nmol/d; P < 0.01). Long-term response: in 3 patients, hormonal parameters failed to respond to serotonin receptor antagonists, which were thus discontinued. An improvement was recorded in the remaining 8 patients, that was prolonged in 3, and transient in 5. In 3 of these latter patients, a marked increase of ACTH was observed before treatment discontinuation. Ketanserin was given to 2 patients with Nelson's syndrome, with only transient ACTH decrease in one, and no changes in ACTH response to CRH after 1 month treatment in both cases. An inhibitory effect of ritanserin and ketanserin on ACTH and cortisol production in Cushing's disease appeared to be limited both in terms of duration of response and number of patients with a satisfactory outcome. However, the results may provide a better understanding of serotonergic modulation in Cushing's disease and lead to therapeutic developments.

Effects of mirtazapine on growth hormone, prolactin, and cortisol secretion in healthy male subjects

In the present study the effects of acute PO-administration of 15 mg mirtazapine on the growth hormone (GH), prolactin (PRL), and cortisol (COR) secretion were examined in eight physically and mentally healthy male subjects, compared to placebo. Mirtazapine is a new antidepressant agent which does not inhibit the reuptake of norepinephrine or serotonin but is an antagonist of presynaptic and, presumably, postsynaptic alpha 2-receptors as well as an antagonist of postsynaptic 5-HT2 and 5-HT3-receptors. After insertion of an i.v. catheter, blood samples were drawn 1 h prior to the administration of mirtazapine or placebo, at time of application, and during the time of 4 h after application in periods of 30 min. Plasma concentrations of GH, PRL, and COR were determined in each blood sample by double antibody RIA methods. The area under the curve (AUC) value was used as parameter for the GH, PRL, and COR response. With respect to GH and PRL secretion, mirtazapine did not show any effects in comparison with placebo. However, in all subjects, the COR concentrations were remarkably lower after mirtazapine compared to placebo, the difference being obvious in the mean value graphs 60 min after the application up to the end of the measurement period. The t-test for paired samples revealed a highly significant difference (P < 0.01) in COR-AUC-values between the mirtazapine group (mean COR-AUC: 1558.07 micrograms/100 ml x 240 min) and the placebo group (mean COR-AUC: 2698.86 micrograms/100 ml x 240 min). Further studies have to elucidate the question whether the demonstrated inhibition of COR secretion after application of 15 mg mirtazapine is caused by central or peripheral effects of this substance.

What can predict postoperative "endocrinological cure" in Cushing's disease?

OBJECTIVE

The goal of surgical treatment for Cushing's disease is "endocrinological cure." The purpose of this study was to determine predictors for postoperative endocrinological cure in Cushing's disease.

METHODS

Postoperative endocrinological studies were evaluated in 18 patients with Cushing's disease who underwent transsphenoidal surgery for selective adenomectomy. Serum adrenocorticotropic hormone (ACTH) levels were measured by radioimmunoassay during the first week after surgery. One week after surgery, a test using corticotropin-releasing hormone (CRH) was performed on each patient to check the reserve function of normal ACTH-secreting cells.

RESULTS

In eight patients, postoperative ACTH levels were below the measurable level for 1 week, and ACTH showed no response to the CRH test. In these patients, serum ACTH and cortisol levels were kept in the normal range with a normal diurnal variation during long-term follow-up. These patients can be defined as endocrinologically cured. In seven patients, the ACTH level returned to within normal range on the day after surgery, but ACTH was provoked by the CRH test. Five of these seven patients showed subsequent re-elevation of ACTH above the normal range. ACTH levels were never normalized in the remaining three patients, and medical treatments were unavoidable.

CONCLUSION

The most reliable indicators for predicting endocrinological cure in Cushing's disease are no response of ACTH to the CRH test in the early postoperative stage and an unmeasurably low ACTH level in the week after surgery. Obtaining a normal range of ACTH level postoperatively is insufficient to define endocrinological cure.

Cushing's syndrome in pregnancy treated by ketoconazole: case report and review of the literature

We report on a 30-year-old female with a pituitary-dependent Cushing's disease, who refused transsphenoidal surgery and was treated with ketoconazole and cabergoline. After approximately 3 years of therapy, the patient herself decided, without the knowledge of her treating physician, to interrupt contraception. As the patient became pregnant she ceased the intake of all medication (between the third and seventh week), but resumed it soon after pregnancy was diagnosed because of relapsing clinical signs. Pregnancy and vaginal delivery at 37 weeks gestation passed uneventfully. The newborn male infant did not demonstrate any congenital malformations and was normally sexually developed. With reference to this case, we discuss the difficulties in the medical treatment of Cushing's syndrome during pregnancy. Whereas outside pregnancy only efficacy and side-effects are taken into account, teratogenicity is an important question in these patients. Experience with different drugs is listed. This is only the second time that ketoconazole has been used during pregnancy for the treatment of Cushing's syndrome. We argue that ketoconazole may be safe as well as effective in pregnancy and, furthermore, without any consequences for the child.

Tumors of the central nervous system

Neoplasia of the central nervous system (CNS) can be divided into two main categories: nonpituitary CNS neoplasia and pituitary adenomas. Nonpituitary CNS neoplasias are generally compressive in nature, although some are also invasive. The majority of reported CNS tumors are secondary with only a few originating from nervous tissue. Pituitary adenomas predominantly occur in the pars intermedia of the older horse. Clinical signs, diagnostic testing, and possible treatments are discussed.

Cyproheptadine treatment in Cushing's disease

Cyproheptadine, a nonselective 5-hydroxytryptamine receptor blocking agent, reduces ACTH and beta-endorphin secretion from the ACTH-producing tumors. A 35-year-old female suffering from Cushing's disease due to microadenoma of the pituitary gland has been followed since the age of 15. Subtotal adrenalectomy followed by total adrenalectomy, pituitary irradiation, and transsphenoidal hypophysectomy, combined with second radiotherapy of the pituitary, were unsuccessful in achieving remission of the disease. Remission was achieved with cyproheptadine up to a dosage of 24 mg/day. Every attempt to discontinue cyproheptadine treatment was accompanied by recurrence of the disease. This is the first case of Cushing's disease in which cyproheptadine treatment has been the only efficacious therapy for a period of 11 yr. Cyproheptadine may be an alternative long-term therapy for Cushing's disease when other methods of treatment fail.

Short and long-term responses to metyrapone in the medical management of 91 patients with Cushing's syndrome

OBJECTIVE

To analyse the clinical and biochemical effects of metyrapone in the treatment of Cushing's syndrome.

DESIGN

An evaluation of the standard clinical practice at one institution.

PATIENTS

Ninety-one patients with Cushing's syndrome: 57 pituitary-dependent Cushing's disease, 10 adrenocortical adenomas, six adrenocortical carcinomas and 18 ectopic ACTH syndrome.

MEASUREMENTS

The acute response to metyrapone was assessed by measuring cortisol, 11-desoxycortisol and ACTH at 0, 1, 2, 3, 4 hours after a test dose of 750 mg of metyrapone. The longer-term effect of metyrapone was judged by measuring serum cortisol at 0900, 1200, 1500, 1800, 2100 and sometimes 2400 h and calculating a mean.

RESULTS

A test dose of 750 mg of metyrapone decreased serum cortisol levels within 2 hours in all groups of patients and this effect was sustained at 4 hours. At the same time, serum 11-desoxycortisol levels increased in all patients, while plasma ACTH increased in patients with pituitary Cushing's disease and the ectopic ACTH-syndrome. Fifty-three patients with Cushing's disease were followed on short-term metyrapone therapy (1 to 16 weeks) before other more definitive therapy. Their mean cortisol levels (median 654 nmol/l, range 408-2240) dropped to the target range of less than 400 nmol/l in 40 patients (75%) on a median metyrapone dose of 2250 mg/day (range 750-6000). Metyrapone was given long term in 24 patients with Cushing's disease who had been given pituitary irradiation, for a median of 27 months (range 3-140) with adequate control of hypercortisolaemia in 20 (83%). In 10 patients with adrenocortical adenomas and six with adrenocortical carcinomas, metyrapone in a median dose of 1750 mg/day (range 750-6000) reduced their mean cortisol levels (median 847 nmol/l, range 408-2000) to less than 400 nmol/l in 13 patients (81%). In 18 patients with the ectopic ACTH-syndrome the 'mean cortisol levels', obtained from five or six samples on the test day (median 1023 nmol/l, range 823-6354) were reduced to less than 400 nmol/l in 13 patients (70%), on a median dose of 4000 mg/day (range 1000-6000). Reduction of cortisol levels was clearly associated with clinical and biochemical improvement. The medication was well tolerated. Transient hypoadrenalism and hirsutism were unusual but were the most common side-effects.

CONCLUSIONS

In our experience metyrapone remains a most useful agent for controlling cortisol levels in the management of Cushing's syndrome of all types.

The Cushing syndromes

The 10 years since this journal's last review of CS have seen extraordinary advances in our understanding of many aspects of its causes, diagnosis, and treatment. The spectrum of what are now called the Cushing syndromes has expanded considerably to include CD, multiple sources of ectopic ACTH secretion, and an apparent autoimmune cause. Improved assays of ACTH and the availability of CRF have provided new insight into the physiology and pathophysiology of the HPA axis and new tools for diagnosis of CS, especially in combination with selective catheterization and sampling. New imaging technology has improved our visualization of pituitary adenomas and has provided powerful methods for identifying tumors ectopically secreting ACTH and primary adrenal tumors. Finally, the refinement of transsphenoidal surgery and its success in treating CD have provided a safe and effective therapy for this disease. For those occasional patients who require medical therapy, drugs are available that decrease steroid biosynthesis. We now have a much better understanding of a fascinating disease process and are able to diagnose and treat it more correctly. One is impatient to see which new pieces of this puzzle will fall into place over the next ten years.

The effect of cyproheptadine and/or bromocriptine on plasma ACTH levels in patients cured of Cushing's disease by bilateral adrenalectomy

Cyproheptadine and bromocriptine have been reported to be therapeutic in suppressing ACTH levels in Cushing's disease and Nelson's syndrome. However, there have been only scattered reports of their effect in suppressing raised ACTH levels found in patients cured of Cushing's disease by bilateral adrenalectomy. In order to assess whether these agents could prove beneficial in such patients we studied 12 patients previously treated with bilateral adrenalectomy alone for Cushing's disease before and after 3 weeks of cyproheptadine and/or bromocroptine therapy. All had raised plasma ACTH values but no patient had evidence of a pituitary macroadenoma. Plasma ACTH and cortisol were sampled 2-hourly for 24 h. Neither drug regime led to any change in plasma levels of cortisol for 24 h after a 20 mg dose of oral hydrocortisone. Plasma ACTH (mean +/- SEM) showed a small but significant overall reduction (523 +/- 45 vs 392 +/- 34 ng/l; P less than 0.05) while on bromocriptine alone (5 mg given at 0800 and 1800 h, n = 5). When each time point was analysed individually this reduction was significant at only five out of 13 time points. At 0400 h plasma ACTH (mean +/- SEM) was 758.4 +/- 298.1 vs 380.2 +/- 166.6; 0600 h, 795 +/- 288.7 vs 477.8 +/- 191.7; 1200 h, 266.8 +/- 106.2 vs 187.0 +/- 80.3; 1400 h, 470.0 +/- 239.0 vs 302.0 +/- 135.9; 1600 h, 548.6 +/- 262.5 vs 394.2 +/- 178.5 ng/l (P less than 0.05). There was no significant change in plasma ACTH during treatment with the combination of bromocriptine and cyproheptadine.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes at multiple levels of the hypothalamo-pituitary adrenal axis following repeated electrically induced seizures

Seizures, including electrically induced seizures (ECS), activate the hypothalamo-pituitary-adrenal (HPA) axis in rats. The present studies were undertaken to characterize the effects of repeated ECS on hormone release and brain adrenal steroid receptors. Repeated ECS led to an increase in adrenal weight, an increase in the corticosterone response to the eighth seizure compared to the first seizure, and an increase in basal plasma corticosterone levels at the trough of the circadian rhythm. Despite increased plasma corticosterone levels at the time of sacrifice, there were no decreases in adrenal steroid receptor numbers in hypothalamus, cortex or hippocampus. In chronic ECS-treated rats which were adrenalectomized overnight to remove glucocorticoids, an increase in Type I (mineralocorticoid) steroid receptors occurred in both hippocampus and cortex. These data suggest that chronic ECS has a trophic effect on Type I receptors and that the higher levels of corticosterone resulting from chronic ECS do not induce adrenal steroid receptor down-regulation.

Multiple functioning paraganglioma associated with polycythemia

Multiple retroperitoneal functioning paraganglioma complicated by polycythemia is reported in the case of a girl who, at the age of 13 years complained of headache, palpitation, and faintness preoperatively. In the retroperitoneal cavity, there were 21 paragangliomas larger than 1 cm in diameter. All were removed surgically in two sections, the first in 1979 and the second in 1983. Bilateral adrenals were macroscopically normal, and her symptoms disappeared. Now the recurrence of retroperitoneal paraganglioma is likely, although there have been no symptoms for 8 years, since the first operation. It is difficult to conclude that the tumors were benign or malignant in this case. Though complication of polycythemia had been diagnosed before the operation, the symptom continued even with the serum erythropoietin level kept in the normal range. Association of polycythemia with paraganglioma is extremely rare, and it is also rare to find more than 10 paragangliomas. Only a limited number of reports have been made on each case in the literature.

Antiserotonergic inhibition of calcitonin-induced increase of beta-endorphin, ACTH, and cortisol secretion

In a previous study we observed that calcitonin increases beta-endorphin, ACTH, and cortisol secretion. We assumed that calcitonin might have a modulatory role on the pituitary function. The present study was initiated to clarify whether this effect is due to a direct pituitary stimulation or to an indirect stimulation through CRF (corticotropin releasing factor). Fourteen healthy subjects, aged 30-60 years were investigated. All the subjects received 100 IU Salmon calcitonin Sandoz i.v. at 8 a.m. (time 0). Plasma beta-endorphin, ACTH and cortisol were estimated every 30 min from -30 to 120 min by specific radioimmunoassay. The same parameters were estimated a second time, at the same intervals, when cyproheptadine 8 mg (7 subjects) and 40 mg propranolol (7 subjects) were given per os at -30 min and calcitonin i.v. at time 0. beta-endorphin, ACTH and cortisol levels (Mean +/- SEM) rose significantly after calcitonin (peak value at 30-90 min) from 5.2 +/- 0.7 to 15.1 +/- 2.6 pmol/l; from 43.0 +/- 2.7 to 70.7 +/- 4.1 pg/ml and from 10.6 +/- 1.5 to 19.6 +/- 2.1 micrograms/100 ml respectively (p less than 0.0001 by analysis of variance and covariance and repeated measures). Propranolol 40 mg (per os) administered at time -30 did not alter the response of beta-endorphin, ACTH and cortisol to calcitonin (infused at time 0). Cyproheptadine, the antiserotonergic substance that inhibits the synthesis and release of CRF completely inhibited the stimulatory effect of calcitonin. We conclude that probably calcitonin has a modulatory role on the hypothalamo-pituitary adrenal axis and that it acts at the hypothalamic level probably by stimulating CRF secretion.

Diseases of the adrenal cortex

The adrenal cortex is functionally a three-dimensional gland that secretes glucocorticoids, mineralocorticoids, and sex steroids. Of these three classes of steroids only the gluco- and mineralocorticoid hormones are necessary to sustain life. The availability of sensitive and specific radioimmunoassays has permitted accurate measurement of practically every steroid hormone secreted by the adrenal cortex. As in other endocrinopathies, suppression studies are employed when hyperfunction is suspected, while provocative tests are used to detect hypofunction. These dynamic studies enable the clinician to evaluate the functional status of the adrenal cortex. The anatomic configuration of the adrenal cortices is delineated by high-resolution computed tomography (and magnetic resonance imaging), obviating the need for invasive procedures such as venography or arteriography. The disorders of the adrenal cortex can be viewed from the dual perspectives of hyperfunction and hypofunction. Clinical expressions of hyperfunctional adrenocortical syndromes include Cushing's syndrome, primary hyperaldosteronism, and the adrenogenital syndrome. The expressions of hypofunctional syndromes include Addison's disease and selective hypoaldosteronism. The diagnosis and treatment of these disorders are outlined in this issue.