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

To characterize the functional aspect of prolactin (Prl) cells coexisting with corticotroph adenomas, pituitary adenoma cells obtained from a patient with Cushing's disease and a patient with Nelson's syndrome, who were associated with hyperprolactinaemia, were cultured in monolayer and their Prl responses to various secretagogues were compared with those of prolactinoma cells in culture. Immunohistochemistry performed in one of these two adenomas demonstrated the presence of Prl-containing cells in addition to ACTH cells. When ACTH-Prl adenoma cells were exposed to ovine corticotrophin-releasing factor (CRF), a dose-dependent increase in both ACTH and Prl secretion was observed, which was blocked by coincubation with hydrocortisone. In contrast, no stimulatory effect of CRF on Prl release was observed in all of the experiments using prolactinoma cells. Thyrotrophin-releasing hormone, which consistently stimulated Prl secretion in ACTH-Prl adenomas, was effective in triggering Prl release in only 25% of the prolactinomas. Exposure of the cultured cells to lysine vasopressin, growth hormone-releasing factor and vasoactive intestinal peptide resulted in an increase in ACTH and Prl secretion in one ACTH-Prl adenoma, however, none of the prolactinomas responded to these stimuli to secrete Prl. Dopamine and somatostatin, on the other hand, uniformly suppressed Prl secretion from ACTH-Prl adenomas as well as from prolactinoma cells. These results suggest that the mode of Prl secretion by mixed ACTH-Prl pituitary adenomas is not identical to that by pure prolactinomas and is, at least in part, common to that of ACTh secretion.
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PMID:Prolactin secretion by mixed ACTH-prolactin pituitary adenoma cells in culture. 285 25

This report describes a 38-year-old patient with prolactinoma, without adrenal or thyroid insufficiency, with syndrome of inappropriate secretion of vasopressin due to downward resetting of the hypothalamic osmoreceptors. Random measurements of plasma and urine osmolality revealed an inappropriately high urine osmolality for a given plasma osmolality. Simultaneous plasma vasopressin levels were within normal limits. Urine dilution after water load was normal. During infusion of hypertonic saline, the osmotic threshold was demonstrated at plasma osmolality of 267 mosmol/kg, which is markedly lower than the normal 287.3 +/- 3.3 mosmol/kg. Thirst sensation seemed to be intact. The defect in the osmoreceptor function might have been induced by the tumor mass or by chronic hyperprolactinemia.
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PMID:Low-set osmotic threshold for vasopressin release in a patient with prolactinoma. 300 38

Prolactinomas pose an increasingly frequent therapeutic dilemma for the clinician. The neurosurgeon caring for the prolactinoma-bearing patient must stay abreast of the most current basic research concerning the pathogenesis of these often difficult tumors. A fascinating and dynamic line of research involves the possibility that prolactinomas arise secondary to a flaw in the normally inhibitory dopaminergic neurohypophyseal axis. The details of this hypothesis are presented, the current literature surrounding this topic is reviewed, and a brief synthesis of the available theoretical models of prolactinoma pathogenesis is provided.
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PMID:Role of defective dopaminergic inhibition of prolactin secretion in the pathogenesis of prolactinoma. 397 42

Transient diabetes insipidus is a well-known complication after transsphenoidal surgery (TSS). On the other hand, transient hyponatremia has been reported as being a delayed complication of TSS. Transient hyponatremia has been attributed to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), but the details of hyponatremia have not been clarified. In the present study, we retrospectively reviewed 110 consecutive patients (39 males and 71 females, age 9-80 years) operated on transsphenoidally for pituitary and hypothalamic tumors. We investigated the frequency, time of onset, duration of hyponatremia after TSS, and analyzed possible factors associated with it. A postoperative sodium concentration <135 mEq/l was observed in 29 (26%) patients. Five patients were excluded from this study because their hyponatremia could be due to either overdose of desmopressin or SIADH for meningitis. Therefore, we investigated 24 (22%) patients with hyponatremia in this study. The sodium levels in the patients with hyponatremia ranged from 110 to 134, with a mean of 126.2 +/- 5.3 mEq/l. Hyponatremia was observed on average on postoperative day 9.5 +/- 2.4, the serum sodium levels normalized within 3.8 +/- 1.7 days. Hyponatremia occurred in patients with non-functioning pituitary adenoma (26%, 11/42), Rathke's cleft cyst (29%, 5/17), prolactinoma (31%, 4/13) and acromegaly (15%, 4/27). 18 patients (75%, 6/24) who developed hyponatremia had macrotumor (>10 mm), and 6 patients (25%, 6/24) had microtumor. The plasma arginine vasopressin (AVP) levels in the patients with hyponatremia ranged from 0.21 to 2.1, with a mean of 0.79 +/- 0.46 pg/ml, and the levels were inversely correlated with plasma osmolality (r = -0.80, p = 0.002). The urine to plasma osmolality ratios were >1. All the patients received appropriate hormonal replacement, including hydrocortisone. These data showed that postoperative hyponatremia after TSS was not rare, and the hyponatremia was mainly associated with SIADH. As the hyponatremia could be a life-threatening complication, all patients should be screened for serum electrolytes after TSS.
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PMID:Hyponatremia after transsphenoidal surgery for hypothalamo-pituitary tumors. 1686 95

A 50-year-old man was admitted to determine the pathogenesis of hyponatremia. He had a poor appetite and was easily fatigued. Physical findings showed that he was conscious and alert. He had neither dry skin or tongue, nor pretibial edema. Laboratory data revealed that the serum sodium level was 110 mmol/l; plasma osmolality, 238 mmol/kg; and urinary osmolality, 417 mmol/kg. Plasma arginine vasopressin was 0.5 pg/ml despite plasma osmolality of 242 mmol/kg. An acute water load showed impaired water excretion, as percent excretion of water load was 30% and minimal urinary osmolality was 642 mmol/kg. Serum prolactin was 254 ng/ml, and anterior pituitary hormones of ACTH, TSH and GH were in the normal ranges. Brain magnetic resonance imaging (MRI) showed a pituitary tumor with a size of 20 x 22 x 21 mm and it pushed a pituitary stalk upward. Immunohistochemistry revealed prolactinoma. After the adenomectomy, serum sodium level has been kept normal with free access to water intake. The present study indicates that syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is manifested in association with pituitary macroadenoma of prolactinoma.
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PMID:SIADH is only an atypical clinical feature in a patient with prolactinoma. 1752 38

Background: Metabolomics-the novel science that evaluates the multitude of low-molecular-weight metabolites in a biological system, provides new data on pathogenic mechanisms of diseases, including endocrine tumors. Although development of metabolomic profiling in pituitary disorders is at an early stage, it seems to be a promising approach in the near future in identifying specific disease biomarkers and understanding cellular signaling networks. Objectives: To review the metabolomic profile and the contributions of metabolomics in pituitary adenomas (PA). Methods: A systematic review was conducted via PubMed, Web of Science Core Collection and Scopus databases, summarizing studies that have described metabolomic aspects of PA. Results: Liquid chromatography tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR) spectrometry, which are traditional techniques employed in metabolomics, suggest amino acids metabolism appears to be primarily altered in PA. N-acetyl aspartate, choline-containing compounds and creatine appear as highly effective in differentiating PA from healthy tissue. Deoxycholic and 4-pyridoxic acids, 3-methyladipate, short chain fatty acids and glucose-6-phosphate unveil metabolite biomarkers in patients with Cushing's disease. Phosphoethanolamine, N-acetyl aspartate and myo-inositol are down regulated in prolactinoma, whereas aspartate, glutamate and glutamine are up regulated. Phosphoethanolamine, taurine, alanine, choline-containing compounds, homocysteine, and methionine were up regulated in unclassified PA across studies. Intraoperative use of ultra high mass resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), which allows localization and delineation between functional PA and healthy pituitary tissue, may contribute to achievement of complete tumor resection in addition to preservation of pituitary cell lines and vasopressin secretory cells, thus avoiding postoperative diabetes insipidus. Conclusion: Implementation of ultra high performance metabolomics analysis techniques in the study of PA will significantly improve diagnosis and, potentially, the therapeutic approach, by identifying highly specific disease biomarkers in addition to novel molecular pathogenic mechanisms. Ultra high mass resolution MALDI-MSI emerges as a helpful clinical tool in the neurosurgical treatment of pituitary tumors. Therefore, metabolomics appears to be a science with a promising prospect in the sphere of PA, and a starting point in pituitary care.
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PMID:Metabolomics-A Promising Approach to Pituitary Adenomas. 3070 68