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)

Nephrogenic diabetes insipidus (NDI) presents a rarely encountered but challenging fluid management problem in the perioperative period. This case is that of a patient with a perforated duodenal ulcer and previously undiagnosed NDI who received standard preoperative and postoperative hydration with normal saline, causing hypernatremia and an inappropriate diuresis. The resulting hypernatremia and hyperosmolality required aggressive hypotonic fluid replacement to return to preoperative values. Though refractory to 1-desamino-8-D-argenine-vasopressin (dDAVP), thiazide diuretics and nonsteroidal anti-inflammatory agents have a role in managing selected patients. Early diagnosis with careful fluid and electrolyte management are critical in successful management of these patients in the perioperative period.
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PMID:Nephrogenic diabetes insipidus secondary to lithium therapy in the postoperative patient: a case report. 797 76

To examine the mechanisms of cell volume regulation in response to hyperosmolality, segments of the inner stripe of rabbit outer medullary collecting duct (OMCDi) were perfused in vitro. The cross-sectional area of the tubule was monitored as an index of the relative cell volume. When luminal and basolateral osmolalities were increased from 290 to 390 mOsm simultaneously, the tubule cell shrank instantaneously and reswelled gradually, showing the so-called regulatory volume increase (RVI). Basolateral Na+ removal and addition of basolateral ethyl isopropyl amiloride (EIPA) decreased the RVI response by 76 and 66%, respectively. By contrast, apical Na+ removal had no effect on this response. RVI response was also inhibited by basolateral, but not luminal, Cl- removal (-63%), by total HCO3- removal (-74%), and by adding basolateral 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) (-62%). Intracellular pH did not change significantly during RVI. Vasopressin increased RVI response by 56%. However, this increase was abolished in the absence of basolateral Na+ and Cl-, and in the presence of basolateral EIPA and DIDS. These results suggest that major mechanisms responsible for RVI are Na(+)-H+ and Cl(-)-HCO3- exchange systems in the basolateral membrane, and that these systems are stimulated by vasopressin in rabbit OMCDi.
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PMID:Mechanisms of regulatory volume increase in collecting duct cells. 800 44

Hypernatremia was detected in a dog that was evaluated because of seizures. During hospitalization, the dog was fully conscious and remained hypernatremic when drinking voluntarily and when water was added to the food. Urine volume increased and urine osmolality decreased during an infusion of hypertonic saline (2.5% NaCl) solution, despite development of progressive hyperosmolality. There was no correlation between plasma antidiuretic hormone concentration and osmolality during the infusion study. The dog released antidiuretic hormone normally after nonosmotic stimulation (ie, apomorphine administration). These findings allowed a diagnosis of hypodipsic hypernatremia caused by destruction of hypothalamic osmoreceptors. At necropsy, there was hydrocephalus, atrophy of the septum pellucidum, and neuraxonal dystrophy of the cuneate nuclei. The underlying neurologic disease responsible for the CNS lesions could not be determined, but hydrocephalus may have led to pressure atrophy in the region of the hypothalamus that contains osmoreceptors.
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PMID:Hypodipsic hypernatremia in a dog with defective osmoregulation of antidiuretic hormone. 818 13

Acetohydroxamic acid (AHA), a urea analogue, is used clinically to dissolve struvite stones because it inhibits the urease produced by Proteus mirabilis. To be effective, the concentration of AHA must be high in the collecting duct system and final urine. Because AHA is structurally similar to urea, we investigated whether AHA is transported by the urea carrier found in the terminal inner medullary collecting duct (IMCD) and the erythrocyte. We examined AHA transport under four conditions known to affect urea movement across the terminal IMCD, i.e., stimulation by vasopressin (AVP) and hyperosmolality, and inhibition by phloretin and urea analogues. The AHA permeability was determined with a 10 mM bath-to-lumen AHA gradient. AHA was measured by ultramicrocolorimetry. Addition of 1 nM AVP to the bath increased the AHA permeability of the perfused terminal IMCD. Increasing perfusate and bath osmolality from 290 to 690 mosmol/kgH2O (by adding NaCl) also increased tubule permeability to AHA. Addition of either 0.25 mM phloretin to the bath or 200 mM thiourea to the lumen reversibly inhibited the AVP-stimulated AHA permeability. AHA-induced osmotic lysis of erythrocytes was inhibited by phloretin or thionicotinamide; AHA inhibited the osmotic lysis induced by the urea analogue acetamide. Thus, in the rat terminal IMCD, both urea and AHA transport are stimulated by AVP and hyperosmolality, and both are inhibited by phloretin and thiourea. In erythrocytes, both urea and AHA transport are inhibited by phloretin or thionicotinamide. Thus AHA is transported by the urea carrier in the terminal IMCD and erythrocyte.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The urease inhibitor acetohydroxamic acid is transported by the urea pathway in rat terminal IMCD. 821 97

We investigated the modulatory role of gonadal steroids on the expression of oxytocin (OT) and vasopressin (AVP) cytoplasmic mRNAs in the paraventricular nucleus and supraoptic nucleus of the osmotically stimulated rat. We chronically administered an oral salt load (2% sodium chloride solution for 5 days) to intact and gonadectomized female and male Sprague-Dawley rats and measured serum sodium, body weight, pituitary content of OT and AVP immunoreactivities, and size and abundance of hypothalamic cytoplasmic OT and AVP mRNA transcripts. Intact and gonadectomized rats that were administered an osmotic challenge developed comparable degrees of hypernatremia and loss of body weight as well as depletion of posterior pituitary stores of OT and AVP. Hyperosmolality induced elongation of the OT and AVP transcripts in intact and gonadectomized animals, but only intact rats had enhanced hypothalamic cytoplasmic OT and AVP mRNA concentrations to this stimulus. Replacement with gonadal steroids restored the up-regulation in OT and AVP gene expression in gonadectomized animals rendered hyperosmolar. The findings support a modulatory role for gonadal steroids in hypothalamic OT and AVP gene expression during osmotic stimulation.
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PMID:Gonadal steroid modulation of oxytocin and vasopressin gene expression in the hypothalamus of the osmotically stimulated rat. 824 94

Ethanol ingestion affects the hypothalamo-neurohypophysial system resulting in increased diuresis, dehydration and hyperosmolality. We studied the supraoptic nucleus, of the hypothalamus, in ethanol-treated rats, to determine if ethanol alone and/or the associated disturbances of water metabolism lead to structural alterations in a nucleus known to play a central role in fluid homeostasis. Groups of male and female rats were ethanol-treated until 12 and 18 months of age and compared with age-matched pair-fed controls. Twelve and 18-month-old control groups and 12-month-old water control groups (rats submitted to chronic dehydration) were also included in this study in an attempt to differentiate between the effects of undernutrition and dehydration/hyperosmolality, and the specific neurotoxic effects of ethanol. We estimated the volume of the supraoptic nucleus and the numerical density of its neurons and calculated the total number of supraoptic neurons. The volume of both supraoptic neurons and neuropil were also estimated. In immunostained material the ratio of vasopressin to oxytocin neurons and the cross-sectional areas of the two neuronal types were evaluated. There was marked neuronal loss in alcohol-treated rats, but the volume of the supraoptic nucleus was increased. The increase in the volume of the supraoptic nucleus correlated with and was due to increases in the volume was particularly marked for vasopressin neurons. No significant differences were found between controls and pair-fed controls in any of the parameters investigated. In water control rats, the volume of the supraoptic nucleus and of the supraoptic neurons and neuropil was also greater than in pair-fed controls. However, the variations found were not as marked as in ethanol-treated rats and there was no cell loss. These findings reveal, for the first time, that chronic ethanol consumption affects the morphology of supraoptic neurons and neuropil and, consequently, the structure of the entire supraoptic nucleus. Moreover, this study supports the view that ethanol has direct neurotoxic effects on supraoptic neurons because the alterations that occur are not mimicked in animals in which water metabolism alone is disturbed.
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PMID:Effects of chronic alcohol consumption and of dehydration on the supraoptic nucleus of adult male and female rats. 825 26

Rats were exposed to osmotic stress either acutely, over periods of 1 or 4 h, or chronically, over several days. In acute experiments, hyposmolality was induced by intraperitoneal infusion of dilute glucose or mannitol solutions, whereas hyperosmolality was induced by use of sodium chloride, concentrated glucose or mannitol solutions, or urea. Chronic hypernatremia was induced by daily administration of sodium chloride to water-deprived animals; chronic hyponatremia was induced by daily injection of antidiuretic hormone supplemented with glucose. Animals were made hyperglycemic using streptozotocin or uremic by ureteral ligation. Where appropriate, animals were anesthetized with thiobutabarbital (Inaktin) or ether. In acute experiments, analysis of the composition of the cardiac ventricle, diaphragm, liver, and renal cortex showed no evidence of cell volume regulatory processes involving transmembrane movement of potassium ions. There was a small but significant increase in free amino acids [measured as ninhydrin-positive substance (NPS)] in cardiac muscle exposed to hypertonic solutions of sodium chloride and glucose but not when plasma osmolality was raised using mannitol. In cerebral cortical tissue, after 4 h of exposure to acute hypertonicity by infusion of sodium chloride or glucose, there was a significant increase in tissue potassium content and a slight increase in NPS content. In chronic experiments, tissue analysis revealed good evidence for cellular volume readjustment only in cerebral cortex and heart. In the cortex, levels of free amino acids, principally taurine and glutamate (plus glutamine), showed large increases during hypernatremia and hyperglycemia and corresponding decreases during hyposmolality. In heart the principal amino acid present was taurine, and it, together with aspartate and glutamate (plus glutamine), showed large changes under osmotic stress. Other tissues analyzed showed only small changes in composition.
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PMID:Response of tissues of the rat to anisosmolality in vivo. 832 70

The abrupt presentation of hypertonic polyuria, polydipsia and hypernatremia, reflects vasopressin deficiency owing to multiple potential etiologies. Diabetes insipidus becomes an emergency and leads to severe hyperosmolality and dehydration when fluid intake does not match obligate losses. Decreased mental alertness may impair the ability to sense thirst or to obtain access to fluids, thus placing patients postoperatively or posttrauma at particular risk of complicated diabetes insipidus. Intravenously administered DDAVP and hydration with hypotonic fluids is the preferred therapy in the acute setting. As diabetes insipidus may be of unpredictable duration, the need for ongoing medical therapy must be frequently reassessed.
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PMID:The diagnosis and management of diabetes insipidus during medical emergencies. 832 95

Hypertonic saline (HS) administered intraperitoneally reduced the intake of sucrose solution infused intraorally in tube-fed decerebrate rats, as it did in control animals. Similarly, either intraperitoneal or intravenous HS markedly decreased the intake of laboratory chow by neurologically intact control rats. These observations complement recent findings that lesions of putative osmoreceptors in the ventral diencephalon, which eliminate thirst and blunt pituitary secretion of vasopressin and oxytocin in response to HS in rats, have no apparent effect on the HS-induced inhibition of food intake. Taken together they support previous studies indicating an important role for the caudal brainstem in the central control of food intake and suggest that such brainstem control may also include the inhibition of food intake induced by acute hyperosmolality.
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PMID:Dehydration anorexia in decerebrate rats. 855 6

Diabetes insipidus (DI), an acute or chronic condition, results from either of two situations: An inadequate secretion of antidiuretic hormone (ADH) from the posterior pituitary gland or an insufficient renal response to adequate levels of ADH. Characterized by massive urinary output despite progressive serum hyperosmolality, hypernatremia, and dehydration, DI can be life-threatening if not promptly diagnosed and appropriately managed. Individuals with renal disease, surgical patients, and persons with cerebral trauma are at risk to develop this condition.
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PMID:Diabetes insipidus. 871 88


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