Effects of salt and protein intake on polyuria in V2RA-treated ADPKD patients.

BACKGROUND: The only treatment proven to be renoprotective in autosomal dominant polycystic kidney disease (ADPKD) is a vasopressin V2-receptor antagonist (V2RA). However, aquaresis-associated side effects limit tolerability. We investigated whether salt and/or protein intake influences urine volume and related endpoints in V2RA-treated ADPKD patients. METHODS: In this randomized, controlled, double-blind, crossover trial, ADPKD patients treated with maximally tolerated dose of a V2RA were included. While on a low salt and low protein diet, patients were given additional salt and protein to mimic regular intake, which was subsequently replaced by placebo in random order during four 2-week periods. Primary endpoint was change in 24-h urine volume. Secondary endpoints were change in quality of life, measured glomerular filtration rate (mGFR), blood pressure and copeptin level. RESULTS: Twelve patients (49 ± 8 years, 25.0% male) were included. Baseline salt and protein intake were 10.8 ± 1.3 g/24-h and 1.2 ± 0.2 g/kg/24-h, respectively. During the low salt and low protein treatment periods, intake decreased to 5.8 ± 1.6 g/24-h and 0.8 ± 0.1 g/kg/24-h, respectively. Baseline 24-h urine volume (5.9 ± 1.2 L) decreased to 5.2 ± 1.1 L (-11%, P = .004) on low salt and low protein, and to 5.4 ± 0.9 L (-8%, P = .04) on low salt. Reduction in 24-h urine volume was two times greater in patients with lower urine osmolality (-16% vs -7%). Polyuria quality of life scores improved in concordance with changes in urine volume. mGFR decreased during the low salt and low protein, while mean arterial pressure did not change during study periods. Plasma copeptin decreased significantly during low salt and low protein periods. CONCLUSION: Lowering dietary salt and protein intake has a minor effect on urine volume in V2RA-treated ADPKD patients. Reduced intake of osmoles decreased copeptin concentrations and might thus increase the renoprotective effect of a V2RA in ADPKD patients.

Intraoperative dexmedetomidine-related polyuria: A case report and review of the literature.

Dexmedetomidine-related polyuria has been observed in animal experimental studies, while only limited cases have been reported in humans. Thus, this rare effect is not well recognized. Herein, we report the case of a 26-year-old man who underwent total thyroidectomy and experienced intraoperative dexmedetomidine-related polyuria, which was subsequently resolved using pituitrin. Moreover, we review the current literature on dexmedetomidine-related polyuria and analyze the potential mechanisms of this rare effect.

Chloroquine attenuates lithium-induced NDI and proliferation of renal collecting duct cells.

Lithium is widely used in psychiatry as the golden standard for more than 60 yr due to its effectiveness. However, its adverse effect has been limiting its long-term use in clinic. About 40% of patients taking lithium develop nephrogenic diabetes insipidus (NDI). Lithium can also induce proliferation of collecting duct cells, leading to microcyst formation in the kidney. Lithium was considered an autophagy inducer that might contribute to the therapeutic benefit of neuropsychiatric disorders. Thus, we hypothesized that autophagy may play a role in lithium-induced kidney nephrotoxicity. To address our hypothesis, we fed mice with a lithium-containing diet with chloroquine (CQ), an autophagy inhibitor, concurrently. Lithium-treated mice presented enhanced autophagy activity in the kidney cortex and medulla. CQ treatment significantly ameliorated lithium-induced polyuria, polydipsia, natriuresis, and kaliuresis accompanied with attenuated downregulation of aquaporin-2 and Na+-K+-2Cl- cotransporter protein. The protective effect of CQ on aquaporin-2 protein abundance was confirmed in cultured cortical collecting duct cells. In addition, we found that lithium-induced proliferation of collecting duct cells was also suppressed by CQ as detected by proliferating cell nuclear antigen staining. Moreover, both phosphorylated mammalian target of rapamycin and ß-catenin expression, which have been reported to be increased by lithium and associated with cell proliferation, were reduced by CQ. Taken together, our study demonstrated that CQ protected against lithium-induced NDI and collecting duct cell proliferation possibly through inhibiting autophagy.

Determinants of Urine Volume in ADPKD Patients Using the Vasopressin V2 Receptor Antagonist Tolvaptan.

RATIONALE & OBJECTIVE: The vasopressin V2 receptor antagonist (V2RA) tolvaptan is the first drug that has been shown to slow the rate of kidney function decline in patients with autosomal dominant polycystic kidney disease (ADPKD). However, V2RAs also cause polyuria, with urine output that averages 6L/d. We assessed determinants of urine volume in patients with ADPKD using V2RAs because such information may help develop strategies to improve V2RA tolerability. STUDY DESIGN: Clinical trial of patients with ADPKD studied at baseline, after 3 weeks of V2RA treatment (tolvaptan, 90/30mg, in the last week), and after a 3-week washout period. SETTING & PARTICIPANTS: The trial included patients with ADPKD with a wide range of kidney function (measured glomerular filtration rates [mGFRs]; range, 18-148mL/min/1.73m2). INTERVENTION: Tolvaptan treatment for 3 weeks. OUTCOMES: 24-hour urine volume. ANALYTICAL APPROACH: Multivariable regression analysis with stepwise backward elimination was performed both during and without V2RA treatment to evaluate the influence of 24-hour osmolar excretion, mGFR, and total kidney volume on associations between tolvaptan and urine volume. RESULTS: Included were 27 patients (48% men, aged 46±9.8 years with mGFRs of 61±35mL/min/1.73m2). V2RA treatment caused a median increase in urine volume of 128% (interquartile range, 75%-202%), to 5,930±1,790mL. 24-hour osmolar excretion was strongly associated with 24-hour urine volume (standardized ß = 0.73; P < 0.001). During V2RA use, no independent associations were detected between 24-hour urine volume and mGFR, total kidney volume, or V2RA concentration. LIMITATIONS: Limited sample size, no standardized diets. CONCLUSIONS: Osmolar excretion is the major determinant of urine volume in patients taking V2RAs as a consequence of the inability to concentrate urine. Restriction of osmolar intake may therefore limit V2RA-induced polyuria, giving patients more control over the aquaretic side effects and improving the tolerability of these drugs.

Hydrochlorothiazide ameliorates polyuria caused by tolvaptan treatment of polycystic kidney disease in PCK rats.

BACKGROUND: Tolvaptan is an effective treatment for polycystic kidney disease (PKD), but also causes unfortunate polyuria. Hydrochlorothiazide (HCTZ) has been shown to reduce urine volume in nephrogenic diabetes insipidus, raising the possibility that HCTZ could also be effective in reducing tolvaptan-induced polyuria. In this study, we examined the combined administration of HCTZ and tolvaptan. METHODS: Male PCK rats were divided into four groups of normal chow (Cont), normal chow plus tolvaptan, gavage HCTZ treatment, and tolvaptan + HCTZ. Biochemical examinations of the plasma and urine were performed as well as histological and molecular (mRNA and protein expression) analyses. RESULTS: Groups treated with tolvaptan had significantly higher 24 h urine excretion, which was significantly reduced in the tolvaptan + HCTZ group after 2 weeks. Cyst size, pERK protein expression, and Cyclin D1 mRNA expression were all significantly reduced in both the tolvaptan and tolvaptan + HCTZ groups, indicating that HCTZ did not affect the beneficial functions of tolvaptan. Notably, aquaporin 2 redistribution from the apical to intracellular domains was observed in tolvaptan-treated rats and was partially reversed in the tolvaptan + HCTZ group. The renal glomerular filtration rate was reduced in the tolvaptan + HCTZ group. Significantly lowered mRNA expression of neuronal nitric oxide synthase, prostaglandin E synthase 2 and renin were also found in the medulla, but not in the cortex. CONCLUSION: HCTZ reduces tolvaptan-induced polyuria without altering its beneficial effects on PKD. This novel therapeutic combination could potentially lead to better PKD treatments and improved quality of life for the affected patients.

Amitraz: A Perpetual Silent Menace Among Children in Developing Countries-A Case Report.

Amitraz is an acaricide and insecticide used to treat ticks, which infest domestic animals in developing countries. Because of its widespread use, it is one of the common poisons unintentionally consumed by infants and children when left unsupervised. A 3-year-old boy was brought with unintentional consumption of Amitraz. On examination, he was found to be progressively drowsy, with an irregular pulse, bradycardia, and hypotension. He was treated with atropine, intravenous fluids, and dopamine infusion; hemodynamic stability was achieved within 36 hours after ingestion. Amitraz is an unusual but deadly poison unintentionally consumed by children. It can be suspected in the setting of rural households in developing countries having pets. There is no antidote available, and treatment is mainly supportive.

Diuretic Effects of Sodium Glucose Cotransporter 2 Inhibitors and Their Influence on the Renin-Angiotensin System.

The renin-angiotensin system (RAS) plays an important role in regulating body fluids and blood pressure. However, inappropriate activation of the RAS contributes to the pathogenesis of cardiovascular and renal diseases. Recently, sodium glucose cotransporter 2 (SGLT2) inhibitors have been used as anti-diabetic agents. SGLT2 inhibitors induce glycosuria and improve hyperglycemia by inhibiting urinary reabsorption of glucose. However, in the early stages of treatment, these inhibitors frequently cause polyuria and natriuresis, which potentially activate the RAS. Nevertheless, the effects of SGLT2 inhibitors on RAS activity are not straightforward. Available data indicate that treatment with SGLT2 inhibitors transiently activates the systemic RAS in type 2 diabetic patients, but not the intrarenal RAS. In this review article, we summarize current evidence of the diuretic effects of SGLT2 inhibitors and their influence on RAS activity.

Tamoxifen attenuates development of lithium-induced nephrogenic diabetes insipidus in rats.

Lithium is widely used in treatment of bipolar affective disorders but often causes nephrogenic diabetes insipidus (NDI), a disorder characterized by severe urinary-concentrating defects. Lithium-induced NDI is caused by lithium uptake by collecting duct principal cells and altered expression of aquaporin-2 (AQP2), which are essential for water reabsorption of tubular fluid in the collecting duct. Sex hormones have previously been shown to affect the regulation of AQP2, so we tested whether tamoxifen (TAM), a selective estrogen receptor modulator, would attenuate lithium-induced alterations on renal water homeostasis. Rats were treated for 14 days with lithium, and TAM treatment was initiated 1 wk after onset of lithium administration. Lithium treatment resulted in severe polyuria and reduced AQP2 expression, which were ameliorated by TAM. Consistent with this, TAM attenuated downregulation of AQP2 and increased phosphorylation of the cAMP-responsive element-binding protein, which induced AQP2 expression in freshly isolated inner-medullary collecting duct suspension prepared from lithium-treated rats. In conclusion, TAM attenuated polyuria dose dependently and impaired urine concentration and downregulation of AQP2 protein expression in rats with lithium-induced NDI. These findings suggest that TAM is likely to be a novel therapeutic option for lithium-induced NDI.

Manganese promotes intracellular accumulation of AQP2 via modulating F-actin polymerization and reduces urinary concentration in mice.

Aquaporin-2 (AQP2) is a water channel protein expressed in principal cells (PCs) of the kidney collecting ducts (CDs) and plays a critical role in mediating water reabsorption and urine concentration. AQP2 undergoes both regulated trafficking mediated by vasopressin (VP) and constitutive recycling, which is independent of VP. For both pathways, actin cytoskeletal dynamics is a key determinant of AQP2 trafficking. We report here that manganese chloride (MnCl2) is a novel and potent regulator of AQP2 trafficking in cultured cells and in the kidney. MnCl2 treatment promoted internalization and intracellular accumulation of AQP2. The effect of MnCl2 on the intracellular accumulation of AQP2 was associated with activation of RhoA and actin polymerization without modification of AQP2 phosphorylation. Although the level of total and phosphorylated AQP2 did not change, MnCl2 treatment impeded VP-induced phosphorylation of AQP2 at its serine-256, -264, and -269 residues and dephosphorylation at serine 261. In addition, MnCl2 significantly promoted F-actin polymerization along with downregulation of RhoA activity and prevented VP-induced membrane accumulation of AQP2. Finally, MnCl2 treatment in mice resulted in significant polyuria and reduced urinary concentration, likely due to intracellular relocation of AQP2 in the PCs of kidney CDs. More importantly, the reduced urinary concentration caused by MnCl2 treatment in animals was not corrected by VP. In summary, our study identified a novel effect of MnCl2 on AQP2 trafficking through modifying RhoA activity and actin polymerization and uncovered its potent impact on water diuresis in vivo.

Combination exposure of melamine and cyanuric acid is associated with polyuria and activation of NLRP3 inflammasome in rats.

The molecular mechanisms of melamine-induced renal toxicity have not been fully understood. The purpose of the study aimed to investigate whether melamine and cyanuric acid induced NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation in the kidney, which may contribute to abnormal water and sodium handling in a rat model. Wistar rats received melamine (Mel; 200 mg·kg body wt-1·day-1), cyanuric acid (CA; 200 mg·kg body wt-1·day-1), or Mel plus CA (Mel + CA; 100 mg·kg body wt-1·day-1, each) for 2 wk. Mel + CA caused damaged tubular epithelial structure and organelles, dilated tubular lumen, and inflammatory responses. Crystals were observed in urine and serum specimen, also in the lumen of dilated distal renal tubules. The combined ingestion of Mel and CA in rats caused a markedly impaired urinary concentration, which was associated with reduced protein expression of aquaporin (AQP)1, 2, and 3 in inner medulla and α-Na-K-ATPase and Na-K-2Cl transporters in cortex and outer medulla. Mel + CA treatment was associated with increased protein expression of CD3 and mRNA levels of CD68 and F4/80 as well as phosphorylation of NF-κB in the kidney. Mel + CA treatment increased protein and mRNA expression of NLRP3 inflammasome components apoptosis-associated speck-like protein containing a caspase recruitment domain, caspase-1, and IL-1ß in the inner medulla of rats. NF-κB inhibitor Bay 11-7082 reduced IL-1ß expression induced by Mel + CA and prevented downregulation of AQP2 in inner medullary collecting duct cell suspensions. In conclusion, Mel + CA treatment caused urinary-concentrating defects and reduced expression of renal AQPs and key sodium transporters, which is likely due to the inflammatory responses and activation of NLRP3 inflammasome induced by crystals formed in the kidney.

Chronic lithium treatment induces novel patterns of pendrin localization and expression.

Prolonged lithium treatment is associated with various renal side effects and is known to induce inner medullary collecting duct (IMCD) remodeling. In animals treated with lithium, the fraction of intercalated cells (ICs), which are responsible for acid-base homeostasis, increases compared with renal principal cells (PCs). To investigate the intricacies of lithium-induced IMCD remodeling, male Sprague-Dawley rats were fed a lithium-enriched diet for 0,1, 2, 3, 6, 9, or 12 wk. Urine osmolality was decreased at 1 wk, and from 2 to 12 wk, animals were severely polyuric. After 6 wk of lithium treatment, approximately one-quarter of the cells in the initial IMCD expressed vacuolar H+-ATPase, an IC marker. These cells were localized in portions of the inner medulla, where ICs are not normally found. Pendrin, a Cl-/[Formula: see text] exchanger, is normally expressed only in two IC subtypes found in the convoluted tubule, the cortical collecting duct, and the connecting tubule. At 6 wk of lithium treatment, we observed various patterns of pendrin localization and expression in the rat IMCD, including a novel phenotype wherein pendrin was coexpressed with aquaporin-4. These observations collectively suggest that renal IMCD cell plasticity may play an important role in lithium-induced IMCD remodeling.

Case report: a thiazide diuretic to treat polyuria induced by tolvaptan.

BACKGROUND: Currently, the vasopressin V2 receptor antagonist tolvaptan is the only available treatment for autosomal dominant polycystic kidney disease (ADPKD), but there are tolerability issues due to aquaretic side-effects such as polyuria. A possible strategy to ameliorate these side-effects may be addition of a thiazide diuretic, this is an established treatment in nephrogenic diabetes insipidus, a condition where vasopressin V2 receptor function is absent. CASE PRESENTATION: We describe a 46-year-old male ADPKD-patient, who was prescribed tolvaptan, which caused polyuria of around 5 l per day. Hydrochlorothiazide was added to treat hypertension, which resulted in a marked decrease in urine production. While using tolvaptan, rate of eGFR decline was - 1.35 mL/min/1.73m2 per year, whereas after hydrochlorothiazide was initiated this was - 3.97 mL/minute/1.73m2 per year. CONCLUSIONS: This case report indicates that while addition of hydrochlorothiazide may improve tolerability of vasopressin V2 receptor antagonists, co-prescription should only be used with great scrutiny as it may decrease tolvaptan effect on rate of ADPKD disease progression.

Aliskiren increases aquaporin-2 expression and attenuates lithium-induced nephrogenic diabetes insipidus.

The direct renin inhibitor aliskiren has been shown to be retained and persist in medullary collecting ducts even after treatment is discontinued, suggesting a new mechanism of action for this drug. The purpose of the present study was to investigate whether aliskiren regulates renal aquaporin expression in the collecting ducts and improves urinary concentrating defect induced by lithium in mice. The mice were fed with either normal chow or LiCl diet (40 mmol·kg dry food-1·day-1 for 4 days and 20 mmol·kg dry food-1·day-1 for the last 3 days) for 7 days. Some mice were intraperitoneally injected with aliskiren (50 mg·kg body wt-1·day-1 in saline). Aliskiren significantly increased protein abundance of aquaporin-2 (AQP2) in the kidney inner medulla in mice. In inner medulla collecting duct cell suspension, aliskiren markedly increased AQP2 and phosphorylated AQP2 at serine 256 (pS256-AQP2) protein abundance, which was significantly inhibited both by adenylyl cyclase inhibitor MDL-12330A and by PKA inhibitor H89, indicating an involvement of the cAMP-PKA signaling pathway in aliskiren-induced increased AQP2 expression. Aliskiren treatment improved urinary concentrating defect in lithium-treated mice and partially prevented the decrease of AQP2 and pS256-AQP2 protein abundance in the inner medulla of the kidney. In conclusion, the direct renin inhibitor aliskiren upregulates AQP2 protein expression in inner medullary collecting duct principal cells and prevents lithium-induced nephrogenic diabetes insipidus likely via cAMP-PKA pathways.

Lithium-induced NDI: acetazolamide reduces polyuria but does not improve urine concentrating ability.

Lithium is the mainstay treatment for patients with bipolar disorder, but it generally causes nephrogenic diabetes insipidus (NDI), a disorder in which the renal urine concentrating ability has become vasopressin insensitive. Li-NDI is caused by lithium uptake by collecting duct principal cells and downregulation of aquaporin-2 (AQP2) water channels, which are essential for water uptake from tubular urine. Recently, we found that the prophylactic administration of acetazolamide to mice effectively attenuated Li-NDI. To evaluate whether acetazolamide might benefit lithium-treated patients, we administered acetazolamide to mice with established Li-NDI and six patients with a lithium-induced urinary concentrating defect. In mice, acetazolamide partially reversed lithium-induced polyuria and increased urine osmolality, which, however, did not coincide with increased AQP2 abundances. In patients, acetazolamide led to the withdrawal of two patients from the study due to side effects. In the four remaining patients acetazolamide did not lead to clinically relevant changes in maximal urine osmolality. Urine output was also not affected, although none of these patients demonstrated overt lithium-induced polyuria. In three out of four patients, acetazolamide treatment increased serum creatinine levels, indicating a decreased glomerular filtration rate (GFR). Strikingly, these three patients also showed a decrease in systemic blood pressure. All together, our data reveal that acetazolamide does not improve the urinary concentrating defect caused by lithium, but it lowers the GFR, likely explaining the reduced urine output in our mice and in a recently reported patient with lithium-induced polyuria. The reduced GFR in patients prone to chronic kidney disease development, however, warrants against application of acetazolamide in Li-NDI patients without long-term (pre)clinical studies.

Magnesium Sulfate: Another Cause of a Solute Diuresis.

In pregnant women, magnesium sulfate infusions are a treatment commonly used for preeclampsia and as a tocolytic agent. In this case report, a 33-year-old woman at 26 weeks of gestation received intravenous magnesium sulfate in Ringer's lactate solution and corticosteroids for preterm uterine contractions without preeclampsia. She developed polyuria of more than 18L in 48 hours, with urine chemistries documenting that magnesium sulfate contributed 30% of the solute in this massive isosthenuric diuresis. Therefore, magnesium sulfate should be added to the common solutes, glucose, sodium chloride, urea, and mannitol, as a cause of solute diureses.

Polyuria due to vasopressin V2 receptor antagonism is not associated with increased ureter diameter in ADPKD patients.

BACKGROUND: Tolvaptan, a vasopressin V2 receptor antagonist, has been shown to reduce the rates of growth in total kidney volume (TKV) and renal function loss in ADPKD patients, but also leads to polyuria because of its aquaretic effect. Prolonged polyuria can result in ureter dilatation with consequently renal function loss. Therefore, we aimed to investigate the effect of tolvaptan-induced polyuria on ureter diameter in ADPKD patients. METHODS: 70 ADPKD patients were included (51 were randomized to tolvaptan and 19 to placebo). At baseline and after 3 years of treatment renal function was measured (mGFR) and MRI was performed to measure TKV and ureter diameter at the levels of renal pelvis and fifth lumbar vertebral body (L5). RESULTS: In these patients [65.7 % male, age 41 ± 9 years, mGFR 74 ± 27 mL/min/1.73 m2 and TKV 1.92 (1.27-2.67) L], no differences were found between tolvaptan and placebo-treated patients in 24-h urine volume at baseline (2.5 vs. 2.5 L, p = 0.8), nor in ureter diameter at renal pelvis and L5 (4.0 vs. 4.2 mm, p = 0.4 and 3.0 vs. 3.1 mm, p = 0.3). After 3 years of treatment 24-h urine volume was higher in tolvaptan-treated patients when compared to placebo (4.7 vs. 2.3 L, p < 0.001), but no differences were found in ureter diameter between both groups (renal pelvis: 4.2 vs. 4.4 mm, p = 0.4 and L5: 3.1 vs. 3.3 mm, p = 0.4). CONCLUSIONS: Tolvaptan-induced polyuria did not lead to an increase in ureter diameter, suggesting that tolvaptan is a safe therapy from a urological point of view.

Polyuria-associated hydronephrosis induced by xenobiotic chemical exposure in mice.

Hydronephrosis is a commonly found disease state characterized by the dilation of renal calices and pelvis, resulting in the loss of kidney function in the severest cases. A generally accepted etiology of hydronephrosis involves the obstruction of urine flow along the urinary tract. In the recent years, we have developed a mouse model of hydronephrosis induced by lactational exposure to dioxin and demonstrated a lack of anatomical obstruction in this model. We also showed that prostaglandin E2 synthesis system plays a critical role in the onset of hydronephrosis. In the present study, we found that neonatal hydronephrosis was not likely to be associated with functional obstruction (impaired peristalsis) but was found to be associated with polyuria and low urine osmolality with the downregulation of proteins involved in the urine concentrating process. The administration of an antidiuretic hormone analog to the dioxin-exposed pups not only suppressed the increased urine output but also decreased the incidence and severity of hydronephrosis. In contrast to the case in pups, administration of dioxin to adult mice failed to induce polyuria and upregulation of prostaglandin E2 synthesis system, and the adult mice were resistant to develop hydronephrosis. These findings suggest the possibility that polyuria could induce hydronephrosis in the absence of anatomical or functional obstruction of the ureter. It is concluded that the present animal model provides a unique example of polyuria-associated type of hydronephrosis, suggesting a need to redefine this disease state.

Protective effect of nitric oxide in aristolochic acid-induced toxic acute kidney injury: an old friend with new assets.

Aristolochic acid (AA) nephropathy (AAN), a progressive tubulointerstitial injury of toxic origin, is characterized by early and transient acute tubular necrosis. This process has been demonstrated to be associated with reduced nitric oxide (NO) production, which can disrupt the regulation of renal function. In this study, we tested the hypothesis that L-arginine (L-Arg) supplementation could restore renal function and reduce renal injury after AA intoxication. C57BL/6 J male mice were randomly subjected to daily i.p. injection of either sterile saline solution or AA (2.5 mg kg(-1)) for 4 days. To determine whether AA-induced renal injuries were linked to reduced NO production, L-Arg, a substrate for NO synthase, was supplemented (5%) in drinking water. Mice intoxicated with AA exhibited features of rapid-onset acute kidney injury, including polyuria, significantly increased plasma creatinine concentrations, proteinuria and fractional excretion of sodium (P < 0.05), along with severe proximal tubular cell injury and increased NADPH oxidase 2 (Nox2)-derived oxidative stress (P < 0.05). This was associated with a significant reduction in NO bioavailability. L-Arg supplementation in AA-treated mice significantly increased NO bioavailability, which in turn improved renal function (creatininaemia, polyuria, proteinuria, fractional excreted sodium and N-acetyl-ß-D-glucosaminidase enzymuria) and renal structure (tubular necrosis and tubular cell apoptosis). These changes were associated with significant reductions in Nox2 expression and in production of reactive oxygen species and with an increase in antioxidant concentrations. Our results demonstrate that preservation of NO bioavailability leads to renal protection in AA-induced acute kidney injury by reducing oxidative stress and maintaining renal function.

Intractable Polyuria Mimicking Diabetes Insipidus-Source Traced to Vecuronium Infusion.

Continuous infusion of vecuronium is a commonly used technique for patients requiring prolonged neuromuscular blockade for mechanical ventilation. As compared with older neuromuscular blocking agents, it confers the advantages of rapid excretion and intermediate duration of action. Prolongation of neuromuscular blockade and muscle weakness are the known complications of continuous vecuronium infusion. This report attempts to describe polyuria, as a hitherto unknown complication of vecuronium infusion, which can occur due to the mannitol present in commercially available preparation of vecuronium bromide.