Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Desmopressin (DDAVP), an arginine vasopressin analogue, markedly stimulates ACTH secretion in patients with Cushing's disease, in contrast to its minimal effect in normal subjects. However, little is known about the mechanisms underlying this action and it appeared to be of interest to evaluate the effect of DDAVP on ACTH-secreting pituitary adenomas in vitro, in comparison with its effect in the same patients in vivo. Pituitary adenomas from 14 patients with Cushing's disease were incubated with DDAVP, corticotrophin-releasing hormone (CRH) and DDAVP together with vasopressin receptor antagonists or CRH. Incubation with DDAVP induced a modest dose-dependent increase in ACTH concentrations which appeared maximal at 10 nM. CRH stimulated ACTH to a greater extent compared with DDAVP and potentiated the effect of DDAVP alone. The DDAVP-induced ACTH increase appeared blunted by vasopressin V(2) and V(3) receptor antagonists. V(3) receptor gene expression was detected by RT-PCR in all adenoma samples except for two which were not responsive to DDAVP in vitro but responsive to the peptide in vivo. Surprisingly, no difference in the in vitro ACTH secretory response was observed between in vivo DDAVP-responsive (ACTH peak>150% baseline) and -unresponsive (ACTH peak<120% baseline) patients, suggesting that the pituitary adenoma is not the sole mediator of the ACTH-releasing effect of DDAVP. In conclusion, the marked stimulatory effect of DDAVP observed in patients with Cushing's disease appears to be mainly dependent on an extrapituitary action, possibly the inhibition of a corticotrophin release-inhibitory factor.
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PMID:Corticotrophin-releasing activity of desmopressin in Cushing's disease: lack of correlation between in vivo and in vitro responsiveness. 1277 17

In October 1955, stocks of the Second International Standard for Posterior Pituitary were running low and the Department of Biological Standards of the National Institute for Medical Research, London, was asked to proceed with the arrangements for an international collaborative assay of material for the Third Standard. A single 142-g batch of posterior-pituitary-lobe powder was obtained and distributed in ampoules, in approximately 30-mg quantities. Samples were sent to 19 laboratories in 10 countries. In all, 185 assays were carried out, 122 for oxytocic activity, 53 for vasopressor activity and 10 for antidiuretic activity.On the basis of the results, which were analysed statistically at the National Institute for Medical Research, it was agreed that the potency of the Third Standard (re-named International Standard for Oxytocic, Vasopressor and Antidiuretic Substances in 1956, in view of the recent synthesis of oxytocin and vasopressin) should be expressed as 2.0 International Units per milligram. The International Unit therefore remains unchanged as 0.5 mg of the dry powder.
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PMID:Third international standard for posterior pituitary; re-named third international standard for oxytocic, vasopressor and antidiuretic substances in 1956. 1358 79

This is the first report describing magnetic resonance (MR) intensity changes of the posterior pituitary gland in the patients suffering from the classical "triphasic" diabetes insipidus (DI) after transsphenoidal surgery for pituitary adenomas. A 21-year-old female and a 54-year-old female were admitted to our hospital with the diagnosis of Cushing's disease and acromegaly due to pituitary microadenomas, respectively. No evidence of DI was found, and T1-weighted MR images exhibited "bright spot" corresponding to the posterior pituitary in both cases. Both experienced the classical "triphasic" pattern of water metabolism disturbance after successful transsphenoidal resection of pituitary adenomas, that is, polyuria-oliguria-polyuria. The MR signal hyperintensity in posterior pituitary was detected during the first polyuric phase, but the hyperintensity disappeared during the second polyuric phase. In addition, "bright spot" was restored along with the recovery from DI in the chronic phase. These findings of serial MR images supported that the first DI phase of the classical triphasic course of water metabolism disturbance was caused by secretional dysfunction of stored vasopressin from the posterior gland, whereas the second DI phase was due to impairment in the functional integrity producing vasopressin-containing granules after depletion of vasopressin in the oliguric phase.
Pituitary 2003
PMID:Serial MR intensity changes of the posterior pituitary in patients with diabetes insipidus after transsphenoidal surgery for pituitary adenomas: report of two cases. 1523 33

Diabetes is associated with increased basal hypothalamo-pituitary-adrenal (HPA) activity and impaired stress responsiveness. Previously, we demonstrated that the HPA response to hypoglycemia is significantly impaired in diabetic rats. In this study our goals were to 1) differentiate between the effects of hyperinsulinemia and those of hypoglycemia per se, and 2) establish whether diabetes lowers peak stress responses. Normal and streptozotocin-diabetic rats were subjected to hyperinsulinemic-euglycemic glucose clamps to evaluate central and peripheral responses. These were compared with peak ACTH and corticosterone responses to restraint and hypoglycemia. Hyperinsulinemia increased CRH and vasopressin mRNA, and plasma ACTH and corticosterone in normal and diabetic rats. In normal animals, insulin-induced activation of ACTH and corticosterone was lower than the responses during either restraint or hypoglycemia. In contrast, ACTH and corticosterone activation in diabetic rats was similar with all three stressors. Pituitary-adrenal axis activation in diabetic animals was also much lower compared with that in normal controls. The response to hyperinsulinemia (euglycemia) was associated with increases in glucocorticoid receptor mRNA in the anterior pituitary and paraventricular nucleus. Hippocampal mineralocorticoid receptor mRNA expression was increased in normal, but not in diabetic, animals. We speculate that the ability to appropriately match the HPA response to the potency of a stressor is related to the ability to alter hippocampal mineralocorticoid receptor expression. In diabetes, this ability is impaired; hence, maximal HPA activation is greatly diminished. This is a novel observation that may have important implications in the treatment of impaired counterregulatory mechanisms in human diabetes.
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PMID:Insulin alone increases hypothalamo-pituitary-adrenal activity, and diabetes lowers peak stress responses. 1556 37

The contributions to our present knowledge and understanding of diabetes insipidus are briefly surveyed. Though a disease presenting with polyuria and thirst had been recognized since Antiquity, it was not until the 17. Century the distinction was made between diabetes insipidus and diabetes mellitus. At the beginning of the 20. Century almost nothing was known about the function of the pituitary. It was generally believed that diabetes insipidus was a renal disease. Two clinical observations in 1912 suggested an association between the hypophysis and diabetes insipidus. This view was supported by the recognition in 1913 that extract of the posterior lobe of the pituitary was effective in diabetes insipidus. Despite much evidence to the contrary, it was assumed that the antidiuretic hormone was produced in the intermediate lobe of the pituitary. Around 1950 it was finally established that 'the posterior lobe hormones' are in fact secreted in the hypothalamus. At the same time the antidiuretic hormone was isolated and synthesized. More recently, progress within genetics has made it possible to characterize in details other rare types of diabetes insipidus.
Pituitary 2004
PMID:Diabetes insipidus: historical aspects. 1563 96

Resistin is a new adipokine expressed in mouse, rat and human adipose tissue. Resistin may be an important link between obesity and insulin resistance, though this controversial view is complicated by the discovery of multiple sites of resistin expression, including human macrophages, placenta and pancreas. In previous studies we demonstrated that the mouse hypothalamo-pituitary system was also a site of resistin production. Pituitary resistin is developmentally regulated, reduced in the ob/ob mouse and severely down-regulated by food deprivation (24 h). An unexpected finding was that hypothalamic resistin mRNA remained unaffected by fasting. The present experiments examined the localization and possible regulation of hypothalamic resistin protein. Using immunohistochemistry we observed a complex network of resistin+ fibres extending rostrally from the arcuate nucleus of the hypothalamus (ARC) to the preoptic area. Labelled cell bodies occurred only in the ARC and in a periventricular region of the dorsal hypothalamus. Hypothalamic resistin immunoreactivity (ir) was unaffected by fasting (48 h) or by a high fat diet, but the periventricular staining was greatly increased in the lactating mouse. Marked reductions in resistin+ fibres were seen in brain tissue from: (a) ob/ob mice, (b) young mice made underweight for their age by raising them in large litters (20 pups per litter) and (c) mice with hypothalamic lesions induced by monosodium glutamate (MSG) or gold thioglucose (GTG). We speculate that the resistin-ir deficit in genetically obese mice, and in severely underweight mice, could be due to low or absent leptin. In contrast, though MSG- and GTG-treated mice have high levels of circulating leptin, in the presence of excessive visceral fat deposits, we hypothesize that damage to the ARC destroys the resistin+ cell bodies. This latter supposition led us to an additional hypothesis, that resistin-ir would be contained in neurons expressing the proopiomelanocortin (POMC) gene. This proved to be correct. Double label immunofluorescence histochemistry revealed that alpha-MSH-ir, a marker for POMC neurons, was co-localized with resistin-ir. In conclusion, our data reveal a second example of an adipocytokine co-localized with a hypothalamic neuropeptide. We reported previously that leptin was co-localized with oxytocin and vasopressin. RT-PCR analysis confirmed that resistin mRNA is readily detectable in ARC, but further work is required to determine whether the resistin gene is expressed in POMC neurons or if resistin is specifically accumulated by these cells. Nonetheless, our data suggest that the hypothalamus is a target tissue for resistin.
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PMID:Hypothalamic resistin immunoreactivity is reduced by obesity in the mouse: co-localization with alpha-melanostimulating hormone. 1580 9

We report the usefulness of a highly sensitive immune complex transfer enzyme immunoassay (ICT-EIA) to detect human chorionic gonadotropin (HCG)-beta and thereby the onset of neurohypophyseal germinoma in its active phase. A 14-year-old girl exhibiting arrested puberty was diagnosed with neurohypophyseal germinoma following observation for two years. This patient initially showed no signs of diabetes insipidus (DI). While ICT-EIA indicated concentrations of HCG-beta higher than normal in cerebrospinal fluid (CSF) and serum, the results obtained with conventional methods were negative. ICT-EIA was also useful to assess the efficacy of treatment.
Pituitary 2004
PMID:Elevated levels of human chorionic gonadotropin-beta, a marker of active neurohypophyseal germinoma, detected by immune complex transfer enzyme immunoassay. 1601 Apr 54

In recent years, a novel understanding of the pathophysiology of adrenal Cushing's syndrome has emerged. The ectopic or aberrant expression of G-protein-coupled hormone receptors in the adrenal cortex was found to play a central role in the regulation of cortisol secretion in ACTH-independent macronodular adrenal hyperplasia (AIMAH) and in some unilateral adrenal adenomas. Various aberrant receptors, functionally coupled to steroidogenesis, have been reported: GIP, vasopressin, beta-adrenergic, LH/hCG, and serotonin receptors have been best characterized, but angiotensin, leptin, glucagon, IL-1 and TSH receptors have also been described. The molecular mechanisms responsible for the aberrant expression of these receptors are currently unknown. One or many of these aberrant receptors are present in most cases of AIMAH and in some cases of adrenal adenomas with overt or sub-clinical secretion of cortisol. Clinical protocols to screen for such aberrant receptors have been developed and should be performed in all patients with AIMAH. The identification of such aberrant regulation of steroidogenesis in AIMAH provides the novel opportunity to treat some of these patients with pharmacological agents that either suppress the endogenous ligand or block the aberrant receptor, thus avoiding bilateral adrenalectomy.
Pituitary 2004
PMID:Aberrant expression of hormone receptors in adrenal Cushing's syndrome. 1601 Apr 57

Pituitary adenomas often present with the symptoms of hormonal hypersecretion, and although medical therapy is available for most hyperfunctioning states, it is not curative. As a result, transsphenoidal pituitary surgery has become a commonly performed neurosurgical procedure with unique challenges for the anesthesiologist due to the distinct medical comorbidities associated with various adenomas. Any type of pituitary tumor may also produce hypopituitarism and local mass effects secondary to the expanding intrasellar mass. Here we review the perioperative concerns surrounding surgery to remove adenomas and decompress the sellar space. Special attention is given to Cushing's disease (hypercortisolism secondary to an adrenocorticotropic hormone-secreting adenoma), acromegaly (secondary to a growth hormone-secreting adenoma), and hyperthyroidism in the setting of thyrotropic adenomas. Operative risks, including bleeding, diabetes insipidus, the syndrome of inappropriate antidiuretic hormone secretion, and hypopituitarism, are addressed in detail. Understanding preoperative assessment, intraoperative management, potential complications, their management, and strategies for avoidance are fundamental to successful perioperative patient care and avoidance of morbidity and mortality.
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PMID:Perioperative management of patients undergoing transsphenoidal pituitary surgery. 1771 70

Adipsic diabetes insipidus (ADI) is a rare condition in which thirst, an essential clinical feature for the prevention of hypernatraemic dehydration, is absent. We report the first case of adipsic diabetes insipidus to occur following surgery for a pituitary macroprolactinoma, with loss of both osmoregulated and baroregulated vasopressin release. Following extensive surgery for a vision threatening macroprolactinoma a 14-year-old boy developed profound hypernatraemia with absent thirst sensation. Detailed investigation, with hypertonic saline infusion and trimetaphan infusion, revealed absence of both osmoregulatory and baroregulatory release of vasopressin. We discuss the investigation and management of such patients and the physiology of hypothalamic-neurohypophyseal dysfunction in such patients.
Pituitary 2006
PMID:Adipsic diabetes insipidus following pituitary surgery for a macroprolactinoma. 1670 10


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