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Pflugers Archiv : European Journal of... Aug 2022Saving body water by optimal reabsorption of water filtered by the kidney leading to excretion of urine with concentrations of solutes largely above that of plasma... (Review)
Review
Saving body water by optimal reabsorption of water filtered by the kidney leading to excretion of urine with concentrations of solutes largely above that of plasma allowed vertebrate species to leave the aquatic environment to live on solid ground. Filtered water is reabsorbed for 70% and 20% by proximal tubules and thin descending limbs of Henle, respectively. These two nephron segments express the water channel aquaporin-1 located along both apical and basolateral membranes. In the proximal tubule, the paracellular pathway accounts for at least 30% of water reabsorption, and the tight-junction core protein claudin-2 plays a key role in this permeability. The ascending limb of Henle and the distal convoluted tubule are impermeant to water and are responsible for urine dilution. The water balance is adjusted along the collecting system, i.e. connecting tubule and the collecting duct, under the control of arginine-vasopressin (AVP). AVP is synthesized by the hypothalamus and released in response to an increase in extracellular osmolality or stimulation of baroreceptors by decreased blood pressure. In response to AVP, aquaporin-2 water channels stored in subapical intracellular vesicles are translocated to the apical plasma membrane and raise the water permeability of the collecting system. The basolateral step of water reabsorption is mediated by aquaporin-3 and -4, which are constitutively expressed. Drugs targeting water transport include classical diuretics, which primarily inhibit sodium transport; the new class of SGLT2 inhibitors, which promotes osmotic diuresis and the non-peptidic antagonists of the V2 receptor, which are pure aquaretic drugs. Disturbed water balance includes diabetes insipidus and hyponatremias. Diabetes insipidus is characterized by polyuria and polydipsia. It is either related to a deficit in AVP secretion called central diabetes insipidus that can be treated by AVP analogs or to a peripheral defect in AVP response called nephrogenic diabetes insipidus. Diabetes insipidus can be either of genetic origin or acquired. Hyponatremia is a common disorder most often related to free water excess relying on overstimulated or inappropriate AVP secretion. The assessment of blood volume is key for the diagnosis and treatment of hyponatremia, which can be classified as hypo-, eu-, or hypervolemic.
Topics: Aquaporin 2; Arginine Vasopressin; Diabetes Insipidus; Diabetes Insipidus, Nephrogenic; Humans; Hyponatremia; Water
PubMed: 35678906
DOI: 10.1007/s00424-022-02712-9 -
Journal of the Royal College of... 1998
Topics: Diabetes Insipidus; Humans; Polyuria; Terminology as Topic
PubMed: 9670165
DOI: No ID Found -
Archives of Disease in Childhood Jul 1998
Review
Topics: Adolescent; Adult; Body Water; Child; Child, Preschool; Deamino Arginine Vasopressin; Diabetes Insipidus; Drinking; Homeostasis; Humans; Infant; Magnetic Resonance Imaging; Polyuria; Renal Agents; Vasopressins
PubMed: 9771260
DOI: 10.1136/adc.79.1.84 -
International Journal of Molecular... Nov 2017Under physiological conditions, excessive loss of water through the urine is prevented by the release of the antidiuretic hormone arginine-vasopressin (AVP) from the... (Review)
Review
Under physiological conditions, excessive loss of water through the urine is prevented by the release of the antidiuretic hormone arginine-vasopressin (AVP) from the posterior pituitary. In the kidney, AVP elicits a number of cellular responses, which converge on increasing the osmotic reabsorption of water in the collecting duct. One of the key events triggered by the binding of AVP to its type-2 receptor (AVPR2) is the exocytosis of the water channel aquaporin 2 (AQP2) at the apical membrane the principal cells of the collecting duct. Mutations of either AVPR2 or AQP2 result in a genetic disease known as nephrogenic diabetes insipidus, which is characterized by the lack of responsiveness of the collecting duct to the antidiuretic action of AVP. The affected subject, being incapable of concentrating the urine, presents marked polyuria and compensatory polydipsia and is constantly at risk of severe dehydration. The molecular bases of the disease are fully uncovered, as well as the genetic or clinical tests for a prompt diagnosis of the disease in newborns. A real cure for nephrogenic diabetes insipidus (NDI) is still missing, and the main symptoms of the disease are handled with s continuous supply of water, a restrictive diet, and nonspecific drugs. Unfortunately, the current therapeutic options are limited and only partially beneficial. Further investigation in vitro or using the available animal models of the disease, combined with clinical trials, will eventually lead to the identification of one or more targeted strategies that will improve or replace the current conventional therapy and grant NDI patients a better quality of life. Here we provide an updated overview of the genetic defects causing NDI, the most recent strategies under investigation for rescuing the activity of mutated AVPR2 or AQP2, or for bypassing defective AVPR2 signaling and restoring AQP2 plasma membrane expression.
Topics: Aquaporin 2; Arginine Vasopressin; Diabetes Insipidus, Nephrogenic; Exocytosis; Humans; Mutation; Receptors, Vasopressin
PubMed: 29125546
DOI: 10.3390/ijms18112385 -
Swiss Medical Weekly May 2020Polyuria-polydipsia syndrome consists of the three main entities: central or nephrogenic diabetes insipidus and primary polydipsia. Reliable distinction between these...
Polyuria-polydipsia syndrome consists of the three main entities: central or nephrogenic diabetes insipidus and primary polydipsia. Reliable distinction between these diagnoses is essential as treatment differs substantially, with the wrong treatment potentially leading to serious complications. Past diagnostic measures using the classical water deprivation test had several pitfalls and clinicians were often left with uncertainity concerning the diagnosis. With the establishment of copeptin, a stable and reliable surrogate marker for arginine vasopressin, diagnosis of the polyuria-polydipsia syndrome has been newly evaluated. Whereas unstimulated basal copeptin measurement reliably diagnoses nephrogenic diabetes insipidus, two new tests using stimulated copeptin cutoff levels showed a high diagnostic accuracy in differentiating central diabetes insipidus from primary polydipsia. For the hypertonic saline infusion test, osmotic stimulation via the induction of hypernatraemia is used. This makes the test highly reliable and superior to the classical water deprivation test, but also requires close supervision and the availability of rapid sodium measurements to guarantee the safety of the test. Alternatively, arginine infusion can be used to stimulate copeptin release, opening the doors for an even shorter and safer diagnostic test. The test protocols of the two tests are provided and a new copeptin-based diagnostic algorithm is proposed to reliably differentiate between the different entities. Furthermore, the role of copeptin as a predictive marker for the development of diabetes insipidus following surgical procedures in the sellar region is described.
Topics: Diabetes Insipidus; Diabetes Mellitus; Diagnosis, Differential; Diagnostic Tests, Routine; Glycopeptides; Humans; Polyuria
PubMed: 32374887
DOI: 10.4414/smw.2020.20237 -
Deutsches Arzteblatt International Oct 2021
Topics: Diabetes Insipidus; Diabetes Mellitus; Humans
PubMed: 34935610
DOI: 10.3238/arztebl.m2021.0312 -
Annales D'endocrinologie Apr 2012Nephrogenic diabetes insipidus (NDI) is caused by an improper response of the kidney to the antidiuretic hormone arginine vasopressin (AVP), leading to a decreased... (Review)
Review
Nephrogenic diabetes insipidus (NDI) is caused by an improper response of the kidney to the antidiuretic hormone arginine vasopressin (AVP), leading to a decreased ability to concentrate urine which results in polyuria and polydipsia. The clinical diagnosis of NDI relies on demonstration of subnormal ability to concentrate urine despite the presence of AVP. NDI is most commonly acquired, secondary to kidney disorders, electrolyte imbalance and various drugs. Congenital forms of NDI are rare, and most commonly inherited in a X-linked manner with mutations of the AVP receptor type 2 (AVPR2). Mutations of the water channel aquaporin-2 (AQP2) can be detected in autosomal recessive or dominant forms of NDI. Management of NDI should focus on free access to drinking water and reduction of polyuria.
Topics: Aquaporin 2; Arginine Vasopressin; Diabetes Insipidus, Nephrogenic; Humans; Mutation; Receptors, Vasopressin
PubMed: 22503803
DOI: 10.1016/j.ando.2012.03.032 -
Endokrynologia Polska 2019In the clinical setting, the diagnosis of neurosarcoidosis in patients with central diabetes insipidus (CDI) is typically based both on symptoms (i.e. polydipsia or... (Review)
Review
INTRODUCTION
In the clinical setting, the diagnosis of neurosarcoidosis in patients with central diabetes insipidus (CDI) is typically based both on symptoms (i.e. polydipsia or polyuria) and brain magnetic resonance imaging (MRI) findings (e.g. pituitary abnormality). However, inconsistent changes in the patient's symptoms and brain MRI findings may occur during the clinical course of the disease. This review was performed to summarise the relationship between symptoms and brain MRI findings in previously reported cases of neurosarcoidosis with CDI.
MATERIAL AND METHODS
Case studies of patients diagnosed with neurosarcoidosis with CDI were collected via a PubMed search of studies published through 30 June 2018.
RESULTS
Thirteen eligible studies were reviewed (20 patients; 12 men, 8 women; mean age 33 years). Polydipsia or polyuria was the first symptom in 13 patients. The mean duration from disease onset to diagnosis was 3.4 months. Brain MRIs showed abnormal findings in the hypothalamus and pituitary for 17 patients. Immunosuppressive drugs were used in 17 patients. For 14 patients, MRI findings improved, while symptoms did not.
CONCLUSION
Patients with both neurosarcoidosis and CDI symptoms often do not improve, despite the fact that brain MRI findings often improve following treatment. More studies involving detailed pathological analyses and longer follow-up periods are necessary.
Topics: Adult; Central Nervous System Diseases; Diabetes Insipidus, Neurogenic; Female; Humans; Male; Pituitary Gland; Sarcoidosis
PubMed: 31681969
DOI: 10.5603/EP.a2019.0035 -
Internal Medicine (Tokyo, Japan) Oct 2003
Topics: Chemotaxis, Leukocyte; Diabetes Insipidus; Female; Humans; Hypopituitarism; Lymphocytes; Pregnancy; Pregnancy Complications; Puerperal Disorders
PubMed: 14606700
DOI: 10.2169/internalmedicine.42.924 -
The Journal of International Medical... Nov 2018The prevalence of juvenile-onset gout has been increasing. Hereditary factors and secondary diseases should be considered in these patients. Adipsic diabetes insipidus... (Review)
Review
The prevalence of juvenile-onset gout has been increasing. Hereditary factors and secondary diseases should be considered in these patients. Adipsic diabetes insipidus (ADI) is characterized by arginine vasopressin (AVP) deficiency, which results in hypotonic polyuria, and dysfunction of thirst osmoreceptors, which results in failure to generate a thirst sensation in response to hypernatremia. We herein report a case of a boy with gouty arthritis, refractory hyperuricemia, prominent hypernatremia, a high creatinine concentration, and a history of surgery for a hypothalamic hamartoma. The patient was diagnosed with central diabetes insipidus after endocrine evaluation. Because he never had symptoms of thirst, the final diagnosis was corrected to ADI. This is the first report of gout due to chronic ADI in an adolescent. Volume contraction due to ADI might be one cause of hyperuricemia and renal impairment in such patients. Moreover, AVP deficiency might directly lead to low urate clearance due to the lack of vasopressin receptor 1 stimulation. Lack of polydipsia and polyuria may delay the diagnosis of ADI and lead to severe complications of a chronic hyperosmolar status. Sufficient and effective establishment of normovolemia is critical for these patients.
Topics: Adolescent; Diabetes Insipidus; Gout; Humans; Hyperuricemia; Joints; Kidney Diseases; Male
PubMed: 30270804
DOI: 10.1177/0300060518800114