No abstract available.
Hyponatremia ; Receptors, Vasopressin

Terlipressin has splanchnic vasoconstrictive effects, and is generally used for the management of gastroesophageal variceal bleeding secondary to liver cirrhosis. Terlipressin is a synthetic arginine vasopressin (AVP) analog containing a nonapeptide sequence. Terlipressin has increased selectivity for the V1 receptor, compared with AVP; hence, it is considered to be a safe vasoconstrictor. However, side effects such as hyponatremia and seizure, although very rare, have been reported. Hyponatremia related to terlipressin may be caused by the syndrome of inappropriate antidiuresis (SIAD), which is a disorder of sodium and water balance characterized by hypotonic hyponatremia without elevation of the antidiuretic hormone level. Here, we report a case of hyponatremic seizure induced by an infusion of terlipressin in a 52-year-old female who had isolated gastric variceal bleeding secondary to alcoholic liver cirrhosis.
Arginine Vasopressin ; Esophageal and Gastric Varices ; Female ; Hemorrhage* ; Humans ; Hyponatremia ; Liver Cirrhosis* ; Liver Cirrhosis, Alcoholic ; Middle Aged ; Receptors, Vasopressin ; Seizures* ; Sodium

Oxytocin, like vasopressin, has been known to act in the IMCD by the activation of adenylyl cyclase through V2 receptor, but the exact mechanism of its action remains to be elucidated. To prove whether oxytocin is involved in the activation of adenylyl cyclase in the renal collecting duct, we measured the cAMP production and urinary cAMP excretion rate. After single IMCD segments of Sprague-Dawley rats were microdissected and treated with different con- centrations of vasopressin(10pM, 10nM) and oxytocin (10pM, 10nM), cAMP production was measured. Urinary cAMP excretion rate was measured after dehydration and intraperitoneal injection of vasopressin and oxytocin. The results are as follows. 1) cAMP production in single IMCD was significantly increased in vasopressin group(10pM: 48,9+/-4.7(mean+/-SE), 10nM:94.6+/-5.3fmol/mm) and oxy-tocin group(10pM: 11.3+/-2.9, 10nM: 65.7+/-6.1fmol/mm) compared with that in the control(3.2+/-0.2fmol/ mm). 2) Urine volume was significantly decreased in dehydration group(40+/-7Ml/hour) and vasopressin group(420+/-120Ml/hour), but urine volume of oxytocin group(1,480+/-230Ml/hour) was not different from that of control(1,550+/-120Ml/hour). Urine osmolality was significantly increased in all experimental groups(control: 737.0+/-132.6, dehydration group : 2,463.9+/- 412.5, vasopressin group : 1,702+/-412.5, oxytocin group 1,293.4+/-117.9mOsm/kg). Urinary cAMP excretion rate was significantly increased in dehydration group(4,149.5+/-1,072.3pmol/hour) and oxytocin group(4,843.3+/-2,341.8pmol/hour), but not in vasopressin group(1,358.1+/-690.2pmol/hour), compared with that in control(49+/-10.7pmoVhour). These results suggest that oxytacin has anti-diuretic effect by the activation of adenylyl cyclase through V2 receptor.
Adenylyl Cyclases ; Dehydration ; Injections, Intraperitoneal ; Osmolar Concentration ; Oxytocin* ; Rats, Sprague-Dawley ; Receptors, Vasopressin ; Vasopressins

Vasopressin, a neurohypophyseal peptide hormone, is the endogenous agonist at V1a, V1b, and V2 receptors. The most important physiological function of vasopressin is the maintenance of water homeostasis through interaction with V2 receptors in the kidney. Vasopressin binds to V2 receptor and increases the number of aquaporin-2 at the apical plasma membrane of collecting duct principal cells. That induces high water permeability across the membrane. Several non-peptide vasopressin receptor antagonists have been developed and are being studied primarily for treating conditions characterized by hyponatremia and fluid overload. Further studies are needed to determine how they are best used in these situations.
Aquaporin 2 ; Cell Membrane ; Homeostasis ; Hyponatremia ; Kidney ; Membranes ; Permeability ; Receptors, Vasopressin ; Vasopressins

BACKGROUNDAs an X-linked recessive way, arginine vasopressin receptor 2 (AVPR2) gene mutation resulted in a hereditary disease - congenital nephrogenic diabetes insipidus (CNDI). We found a suspect clinical CNDI pedigree. In order to identify the genetic etiology, we performed the genetic analysis.

METHODSThe clinical features of the proband and his family members were recorded. The laboratory tests and imaging inspections were analyzed. The water deprivation and pituitrin loading test were performed in the proband and his brother. The genomic DNA of all the members of the pedigree was extracted and then PCR amplification on AVPR2 gene was carried out. Sequencing in both directions was performed to identify mutation on AVPR2 gene.

RESULTSBoth the proband and his brother were diagnosed as CNDI, meanwhile the other members of this pedigree were normal. No severe biochemical abnormality was found in the two CNDI patients. Both the patients had moderate urinary retention, severe megaloureter and hydronephrosis, and mild renal insufficiency. Two mutations of AVPR2 gene were discovered in the 3rd exon in the patients, a silent mutation L309L and a nonsense mutation R337X. The AVPR2 gene R337X mutation was co-segregated with CNDI. R337X mutation was not a reported mutation in the mainland of China.

CONCLUSIONThe AVPR2 gene R337X mutation was also a genetic etiology of CNDI patients in the mainland of China.

Adult ; Diabetes Insipidus, Nephrogenic ; genetics ; Female ; Humans ; Male ; Mutation ; Pedigree ; Receptors, Vasopressin ; genetics ; Vasopressins ; genetics

Ascites is the most common complication of liver cirrhosis, but its pharmacological management is unsatisfactory in some patients because of a lack of response to treatment with conventional diuretics. Patients with cirrhosis and ascites generally have increased non-osmotic secretion of vasopressin which participates in the pathogenesis of fluid retention. Vaptans are a new family of orally active drugs that increase urine volume by antagonizing specifically the vasopressin receptors in the principal cells of the collecting ducts that have been shown to correct dilutional hyponatremia effectively. They also seem to be promising in the management of ascites by reducing the increased extracellular fluid volume in conditions associated with water retention including liver cirrhosis. However, there is a paucity of information on whether vaptans might have beneficial effect in enhancing ascites reduction in patients with cirrhosis. This review addresses the pharmacological actions of vaptans, their clinical applications, and future potential roles in managing patients with liver cirrhosis and ascites.
Ascites ; Diuretics ; Extracellular Fluid ; Fibrosis ; Humans ; Hyponatremia ; Liver ; Liver Cirrhosis ; Receptors, Vasopressin ; Retention (Psychology) ; Vasopressins ; Water

Hyponatremia is the most common electrolyte disorder in hospitalized patients. Many studies documented that it was related to increased morbidity and mortality in patients with congestive heart failure, liver cirrhosis, and neurologic diseases. Although knowledge of hyponatremia has been cumulated, the optimal management of hyponatremia remains incompletely established in clinical practice because of the diversity of underlying disease states, and its multiple causes with differing pathophysiologic mechanisms. Since vasopressin receptor antagonists have unique aquaretic effect to selectively increase electrolytes-free water excretion, clinicians could apply a more effective method to treat hyponatremia. Tolvaptan has significant evidence that it improves serum sodium levels in patients with euvolemic or hypervolemic hyponatremia related with heart failure, cirrhosis or syndrome of inappropriate anti-diuretic hormone. Tolvaptan has acceptable safety and tolerability for long-term usage in chronic hyponatremia, and the beneficial effects on serum Na+ occurred in patients with both mild and marked hyponatremia.
Benzazepines ; Fibrosis ; Heart Failure ; Humans ; Hyponatremia ; Liver Cirrhosis ; Receptors, Vasopressin ; Sodium ; Water

Hyponatremia is commonly encountered in patients with heart failure and has a poor prognosis. Tolvaptan, a novel selective vasopressin V2 receptor blocker, has received attention as an effective drug for treating the syndrome of inappropriate antidiuretic hormone secretion and hypervolemic hyponatremia. However, the safety of tolvaptan in the treatment of hyponatremia is not clear. We experienced a 78-year-old woman with a history of heart failure, atrial fibrillation, and hyponatremia who developed osmotic demyelination syndrome as an unexpected response to treatment with tolvaptan.
Aged ; Atrial Fibrillation ; Demyelinating Diseases* ; Female ; Heart Failure* ; Heart* ; Humans ; Hyponatremia ; Prognosis ; Receptors, Vasopressin

OBJECTIVE: To explore the genetic basis for pedigree affected with hereditary nephrogenic diabetes insipidus (HNDI). METHODS: Next generation sequencing (NGS) with an osteology system gene panel was carried out for the proband. Suspected mutation was validated by Sanger sequencing of two relatives with similar symptoms and two unaffected relatives from the pedigree. RESULTS: The proband was found to carry a c.856C>T mutation of the AVPR2 gene. The same mutation was detected in the two relatives with similar symptoms and one unaffected healthy relative. CONCLUSION The HNDI in this pedigree may be attributed to the c.856C>T mutation of the AVPR2 gene.
Diabetes Insipidus, Nephrogenic ; High-Throughput Nucleotide Sequencing ; Humans ; Mutation ; Pedigree ; Receptors, Vasopressin

Humans ; Tolvaptan/therapeutic use* ; Ascites/drug therapy* ; Receptors, Vasopressin ; Liver Cirrhosis/drug therapy* ; Sodium