Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cushing's syndrome results from prolonged exposure to excess glucocorticoids. Patients with Cushing's syndrome may develop multiple metabolic problems including obesity, hyperglycemia, hypertension, depression, low bone mass, muscle atrophy, and hypogonadism. Cutaneous manifestations of hypercortisolism include skin atrophy, excessive bruising, purple striations, poor wound healing, facial plethora, vellous hypertrichosis and hirsutism. Diagnostic tests used to screen for Cushing's syndrome include 24-hour urine cortisol, the 1 mg dexamethasone suppresion test, and late night salivary cortisol. A normal screening test excludes the diagnosis of Cushing's. Patients with an abnormal screening test should be referred to an endocrinologist for complete evaluation of the pituitary-adrenal axis.
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PMID:Cushing's syndrome. 1682 7

The role of the human hypothalamus in the neuroendocrine response to illness has only recently begun to be explored. Extensive changes in the hypothalamus-pituitary-thyroid (HPT) axis occur within the framework of critical illness. The best-documented change in the HPT axis is a decrease in serum concentrations of the biologically active thyroid hormone triiodothyronine (T3). From studies in post-mortem human hypothalamus it appeared that low serum T3 and thyrotropin (TSH) during illness (nonthyroidal illness, NTI) are paralleled by decreased thyrotropin-releasing hormone (TRH)mRNA expression in the hypothalamic paraventricular nucleus (PVN), pointing to a major alteration in HPT axis setpoint regulation. A strong decrease in TRHmRNA expression is also present in the PVN of patients with major depression as well as in glucocorticoid-treated patients. By inference, hypercortisolism in hospitalized patients with severe depression or in critical illness may induce down-regulation of the HPT axis at the level of the hypothalamus. In order to start defining the determinants and mechanisms of these setpoint changes in various clinical conditions, it is important to note that an increasing number of hypothalamic proteins appears to be involved in central thyroid hormone metabolism. In recent studies, we have investigated the distribution and expression of thyroid hormone receptor (TR) isoforms, type 2 and type 3 deiodinase (D2 and D3), and the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) in the human hypothalamus by a combination of immunocytochemistry, mRNA in situ hybridization and enzyme activity assays. Both D2 and D3 enzyme activities are detectable in the mediobasal hypothalamus. D2 immunoreactivity is prominent in glial cells of the infundibular nucleus/median eminence region and in tanycytes lining the third ventricle. Combined D2, D3, MCT8 or TR immunocytochemistry and TRHmRNA in situ hybridization indicates that D3, MCT8 and TRs are all expressed by TRH neurons in the PVN, whereas D2 is not. Taken together, these results suggest that the prohormone thyroxine (T4) is taken up in glial cells that convert T4 into the biologically active T3 via the enzyme D2; T3 is subsequently transported to TRH producing neurons in the PVN where it may bind to TRs and/or may be degraded into inactive iodothyronines by D3. This model for thyroid hormone action in the human hypothalamus awaits confirmation in future experimental studies.
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PMID:Hypothalamic thyroid hormone feedback in health and disease. 1687 76

The chronic mild stress (CMS) model has been established as a realistic model of depressive disorder as it simulates anhedonia. In the present study, the consumption of sucrose solution was decreased in the rats exposed to CMS, which coincided with many published studies. Since depression is a multifaceted disorder, and a number of symptoms may be present, including circadian rhythm disturbances, we attempted to find the chronobiological abnormalities in CMS rats. After 4-week of the stress procedure, the rhythmic pattern of rectal temperature in the CMS group was extinguished. In particular, the temperature in the CMS group in the light phase was significantly higher than that in the control group. The plasma corticosterone levels in the CMS group were remarkably increased in the light phase compared to the control group, but not in the dark phase. It was concluded that the CMS procedure caused the disturbance of circadian rhythms with hyperthermia and hypercortisolism.
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PMID:Chronobiological disturbances with hyperthermia and hypercortisolism induced by chronic mild stress in rats. 1690 63

Corticotropin-releasing hormone (CRH), the principal regulator of the hypothalamic-pituitary-adrenal axis, has been identified in various organ systems, including the immune and the female and male reproductive systems. CRH-like immunoreactivity has been reported in peripheral inflammatory sites and in a number of reproductive organs, including the ovaries, endometrial glands, decidualized endometrial stroma, placenta, decidua, and the testes. Therefore, "immune" and "reproductive" CRH are forms of "tissue" CRH; i.e., CRH found in peripheral tissues. Immune CRH plays a direct immunomodulatory role as an autocrine/paracrine mediator of inflammation. Immune CRH participates in several experimental inflammations and, in humans, in inflamed tissues from patients with autoimmune and inflammatory diseases. One of the early effects of immune CRH is the degranulation of mast cells and the release of histamine and several inflammatory cytokines. Reproductive CRH is regulating reproductive functions with an inflammatory component, such as ovulation, luteolysis, decidualization, implantation, and early maternal tolerance. Placental CRH participates in the physiology of pregnancy and the onset of labor. Circulating placental CRH is responsible for the physiologic hypercortisolism of the latter half of pregnancy. Postpartum, this hypercortisolism is followed by a transient adrenal suppression, which may explain the blues/depression and increased autoimmune phenomena observed during this period.
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PMID:Peripheral corticotropin-releasing hormone is produced in the immune and reproductive systems: actions, potential roles and clinical implications. 1712 18

Hypercortisolism is a common trait of Cushing's disease and depression. These two disorders also share hippocampal volume decrease and cognitive deficits. However, experimentally induced hypercortisolism induces neuronal atrophy, which has been proposed to be the phenomenon underlying the hippocampal shrinkage. We hypothesized that the above-mentioned atrophy is due to a deleterious effect of high concentrations of glucocorticoids on cytoskeletal proteins. One or two pellets (100 mg each) of corticosterone were subcutaneously implanted in adult rats. Twenty-one days later, light, medium and heavy subunits of intermediate neurofilaments (NFL, NFM and NFH) and the microtubule-associated protein 2 (MAP2) were quantified by immunohistochemistry in Ammon's horn and dentate gyrus. We also evaluated the in vitro glutamate release in hippocampal slices. Both doses of corticosterone induced a decrement of NFL, NFM and NFH in both hippocampal areas but only 200 mg decreased MAP2. This dose also diminished the potassium-stimulated glutamate release. All of these changes seemed not to be due to neuron loss, as no decrement in neuron-specific nuclear protein-positive cells was found. With the exception of NFL, the above-mentioned diminution was not observed in the globus pallidus, one of the brain regions with the lowest glucocorticoid receptor density. These results provide a subcellular insight into the trophic changes found in experimental models of hypercortisolism. The coincidence between decrements in MAP2 and glutamate release suggests possible links between high glucocorticoid levels, dendritic atrophy and the cognitive impairment reported in patients suffering from Cushing's disease and depression.
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PMID:Chronic treatment with high doses of corticosterone decreases cytoskeletal proteins in the rat hippocampus. 1722 84

Among endocrine disorders, Cushing's syndrome (CS) is certainly one of the most challenging to endocrinologists due to the difficulties that often appear during investigation. The diagnosis of CS involves two steps: confirmation of hypercortisolism and determination of its etiology. Biochemical confirmation of the hypercortisolaemic state must be established before any attempt at differential diagnosis. Failure to do so will result in misdiagnosis, inappropriate treatment, and poor management. It should also be kept in mind that hypercortisolism may occur in some patients with depression, alcoholism, anorexia nervosa, generalized resistance to glucocorticoids, and in late pregnancy. Moreover, exogenous or iatrogenic hypercortisolism should always be excluded. The three most useful tests to confirm hypercortisolism are the measurement of 24-h urinary free cortisol levels, low-dose dexamethasone-suppression tests, and determination of midnight serum cortisol or late-night salivary cortisol. However, none of these tests is perfect, each one has different sensitivities and specificities, and several are usually needed to provide a better diagnostic accuracy. The greatest challenge in the investigation of CS involves the differentiation between Cushing's disease and ectopic ACTH syndrome. This task requires the measurement of plasma ACTH levels, non-invasive dynamic tests (high-dose dexamethasone suppression test and stimulation tests with CRH or desmopressin), and imaging studies. None of these tests had 100% specificity and their use in combination is usually necessary. Bilateral inferior petrosal sinus sampling is mainly indicated when non-invasive tests do not allow a diagnostic definition. In the present paper, the most important pitfalls in the investigation of CS are reviewed.
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PMID:Pitfalls in the diagnosis of Cushing's syndrome. 1820 58

Pseudo-Cushing syndromes are a heterogeneous group of disorders, including alcoholism, anorexia nervosa, visceral obesity, and depression, which share many of the clinical and biochemical features of Cushing's syndrome. The mechanisms responsible for the genesis of pseudo-Cushing's syndrome are poorly understood. It has been suggested that hypercortisolism of pseudo-Cushing syndrome may be the result of increased hypothalamic corticotrophin-releasing hormone (CRH) secretion in the context of a hypothalamic-pituitary-adrenal axis that is otherwise normally constituted. The substantial overlap in clinical and biochemical features among several patients with Cushing syndrome and those with pseudo-Cushing syndromes can make the differential diagnosis difficult. Distinguishing between pseudo-Cushing's syndrome and true Cushing's syndrome is critical for preventing the unnecessary and potentially harmful treatment of such patients. This brief review summarizes the main pathophysiological events of pseudo-Cushing syndromes and provides a useful strategy for differential diagnosis.
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PMID:[Pseudo-Cushing states]. 1820 68

A 56-year-old woman suffered from severe depression due to Cushing's syndrome with right adrenal adenoma. She had a normal mental state before developing Cushing's syndrome. Because of her depressive state, informed consent for the treatment could not be obtained, and oral administration of 1.5 g/day metyrapone was commenced. After two weeks, her mental state had markedly improved. She subsequently underwent a right adrenalectomy, and metyrapone administration was terminated on the day of surgery. Without modification on the replacement of corticosteroids, the postoperative course was uneventful. Preoperative management of Cushing's syndrome with metyrapone may be useful in cases of severe psychiatric disturbances due to hypercortisolism.
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PMID:Preoperative management of Cushing's syndrome with metyrapone for severe psychiatric disturbances. 1838 Aug 29

A pattern of performance on a word list learning task known as a reduced primacy effect has been shown to be characteristic of Alzheimer's disease (AD) and can distinguish AD from depression. Deficits in memory and hippocampal atrophy seen in AD have been associated with hypercortisolism. The present study evaluated whether the reduced primacy effect is associated with elevated salivary cortisol in a sample of 40 healthy older community-dwelling adults participating in a study of memory and stress. We found that primacy, but not recency, was associated with higher salivary cortisol levels. In addition, participants who showed a reduced primacy had higher salivary cortisol levels than those with a normal serial position curve. Results suggest that there may be value to examining both serial position curves and changes to cortisol patterns over time as potential predictors of cognitive decline in healthy older adults.
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PMID:The relation of salivary cortisol to patterns of performance on a word list learning task in healthy older adults. 1877 53

Combined exposures to maternal lead (Pb) and prenatal stress (PS) can act synergistically to enhance behavioral and neurochemical toxicity in offspring. Maternal Pb itself causes permanent dysfunction of the body's major stress system, the hypothalamic pituitary adrenal (HPA) axis. The current study sought to determine the potential involvement of altered negative glucocorticoid feedback as a mechanistic basis of the effects in rats of maternal Pb (0, 50 or 150 ppm in drinking water beginning 2 mo prior to breeding), prenatal stress (PS; restraint on gestational days 16-17) and combined maternal Pb+PS in 8 mo old male and female offspring. Corticosterone changes were measured over 24 h following an i.p. injection stress containing vehicle or 100 or 300 microg/kg (females) or 100 or 150 microg/kg (males) dexamethasone (DEX). Both Pb and PS prolonged the time course of corticosterone reduction following vehicle injection stress. Pb effects were non-monotonic, with a greater impact at 50 vs. 150 ppm, particularly in males, where further enhancement occurred with PS. In accord with these findings, the efficacy of DEX in suppressing corticosterone was reduced by Pb and Pb+PS in both genders, with Pb efficacy enhanced by PS in females, over the first 6 h post-administration. A marked prolongation of DEX effects was found in males. Thus, Pb, PS and Pb+PS, sometimes additively, produced hypercortisolism in both genders, followed by hypocortisolism in males, consistent with HPA axis dysfunction. These findings may provide a plausible unifying biological mechanism for the reported links between Pb exposure and stress-associated diseases and disorders mediated via the HPA axis, including obesity, hypertension, diabetes, anxiety, schizophrenia and depression. They also suggest broadening of Pb screening programs to pregnant women in high stress environments.
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PMID:Alterations in glucocorticoid negative feedback following maternal Pb, prenatal stress and the combination: a potential biological unifying mechanism for their corresponding disease profiles. 1897 74


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