The diurnal variation of plasma vasopressin (AVP), urinary excretion rate, urinary osmolality, and serum osmolality was studied twice in 15 patients with enuresis and in 11 age, weight, and sex matched nonenuretic normal subjects. A diurnal rhythm of AVP with constant levels during the day (8 AM-10 PM) and a highly significant increase during the night (10 PM-8 AM) was found in normal subjects. In contrast, enuretics showed a significantly less pronounced nocturnal increase in AVP with significantly lower nocturnal levels than normal subjects. Normal subjects showed a diurnal rhythm in urinary excretion rate reciprocal to urinary osmolality with a low and highly concentrated nocturnal urinary output. In enuretics, however, this normal diurnal rhythm was absent. In conclusion, an abnormal diurnal rhythm of AVP seems to be an important pathophysiological factor in enuresis, explaining the abnormally high nocturnal urinary volume and the low nocturnal urinary osmolality found in these patients.

No abstract

Nocturia is a strong predictor of mortality, more so in younger men and women than in the elderly, with a dose-response pattern in increased mortality risk with increasing number of voiding episodes nightly. Potential underlying mechanisms of the observed association of nocturia and increased mortality risk include sleep disruption and subsequent development of related comorbid conditions.

Desmopressin orally disintegrating tablet is an effective and well-tolerated treatment for patients with nocturia. Further exploration of the lower dose range is warranted.

Nocturia in a large proportion of elderly men with lower urinary tract symptoms is caused by nocturnal polyuria and natriuresis.

Background Nocturia, a common complaint in aging men and women, is frequently cited as the cause of nocturnal awakenings leading to sleep loss, daytime fatigue, and reduced quality of life (QOL). Objective Investigate the association of nocturia with QOL and depressive symptoms among men and women. Design, setting, and participants A population-based epidemiologic survey of urologic symptoms among persons aged 30–79 yr. A multistage stratified cluster sample design was used to randomly sample 5503 residents of Boston, MA, USA. Measurements Nocturia was defined as a self-report of two or more voiding episodes nightly or having to get up to urinate more than once nightly “fairly often,” “usually,” or “almost always.” QOL was assessed using the physical and mental health component scores of the 12-Item Short-Form Survey (SF-12). Depression was assessed using the Center for Epidemiological Studies Depression Scale. Multiple linear and logistic regression methods were used to model the nocturia and QOL association and to control for confounders. Results and limitations Nocturia was associated with decreased SF-12 scores for both the physical and mental health components after multivariate adjustment. Nocturia was also associated with increased odds of depressive symptoms (men: adjusted odds ratio [OR]: 2.79; 95% confidence interval [CI], 1.81–4.31; women: adjusted OR: 1.80; 95% CI, 1.29–2.51). Among women who reported sleep interference due to urologic symptoms, nocturia was associated with a threefold increase in odds of depression. In this cross-sectional analysis, the temporal sequence of causality of the nocturia and depression association could not be assessed. Conclusions Nocturia is associated with decreased QOL and with an increased prevalence of depressive symptoms in both men and women.

The diurnal antidiuretic hormone levels were studied in eleven enuretics and related to urine production and functional bladder capacity. A fluid deprivation test monitoring antidiuretic hormone levels was undertaken in four patients. The study suggests that the normal increase in nighttime antidiuretic hormone levels is absent in enuretics, who show a stable hormone level both day and night. Consequently the volume of night urine production approximates day urine production per hour. The functional bladder capacity was clearly exceeded at night in eight of eleven patients. The fluid deprivation test showed a normal response to fluid deprivation. In conclusion, the study adds further evidence that bladder capacity is a major factor in enuresis. Urine volumes that exceed bladder capacity at night may be caused by a lack of diurnal rhythmicity in antidiuretic hormone levels.

Juul KV, Bichet DG, Nielsen S, Nørgaard JP. The physiological and pathophysiological functions of renal and extrarenal vasopressin V2 receptors. Am J Physiol Renal Physiol 306: F931-F940, 2014. First published March 5, 2014 doi:10.1152/ajprenal.00604.2013.-The arginine vasopressin (AVP) type 2 receptor (V2R) is unique among AVP receptor subtypes in signaling through cAMP. Its key function is in the kidneys, facilitating the urine concentrating mechanism through the AVP/V2 type receptor/aquaporin 2 system in the medullary and cortical collecting ducts. Recent clinical and research observations strongly support the existence of an extrarenal V2R. The clinical importance of the extrarenal V2R spans widely from stimulation of coagulation factor in the endothelium to as yet untested potential therapeutic targets. These include V2R-regulated membranous fluid turnover in the inner ear, V2R-regulated mitogensis and apoptosis in certain tumor tissues, and numerous other cell types where the physiological role of V2Rs still requires further research. Here, we review current evidence on the physiological and pathophysiological functions of renal and extrarenal V2Rs. These functions of V2R are important, not only in rare diseases with loss or gain of function of V2R but also in relation to the recent use of nonpeptide V2R antagonists to treat hyponatremia and possibly retard the growth of cysts and development of renal failure in autosomal dominant polycystic kidney disease. The main functions of V2R in principal cells of the collecting duct are water, salt, and urea transport by modifying the trafficking of aquaporin 2, epithelial Na ϩ channels, and urea transporters and vasodilation and stimulation of coagulation factor properties, mainly seen with pharmacological doses of 1-desamino-8-D-AVP. The AVPR2 gene is located on the X chromosome, in a region with high probability of escape from inactivation; this may lead to phenotypic sex differences, with females expressing higher levels of transcript than males. vasopressin V 2 receptor; arginine vasopressin V2 receptor; arginine vasopressin; desmopressin; extrarenal vasopressin V 2 receptor THE PURPOSE OF THIS REPORT is to review current evidence on the physiological and pathophysiogical functions of renal and extrarenal arginine vasopressin (AVP) type 2 receptors, referred to as V2Rs (Fig. 1).AVP is an important neurohypophyseal nonapeptide that, via its three receptor types, is primarily responsible for regulating osmotic homeostasis of body fluids, volume homeostasis, and vasoconstriction in addition to an array of central functions such as memory and learning (17,29). In addition to these endocrine functions, AVP also contributes to regulating mitogenesis, cell survival, and death (apoptosis) (77).AVP is released from its storage site in the posterior pituitary (Fig. 2) by highly sensitive osmotic stimuli, specifically by a Ͻ1-2% increase in plasma osmolarity, as originally detailed in the 1940s through classic research by Prof. E. B. Verney (125). AVP release may also ...