Increased Milk Protein Concentration in a Rehydration Drink Enhances Fluid Retention Caused by Water Reabsorption in Rats.

Science.gov (United States)

Ito, Kentaro; Saito, Yuri; Ashida, Kinya; Yamaji, Taketo; Itoh, Hiroyuki; Oda, Munehiro

2015-01-01

A fluid-retention effect is required for beverages that are designed to prevent dehydration. That is, fluid absorbed from the intestines should not be excreted quickly; long-term retention is desirable. Here, we focused on the effect of milk protein on fluid retention, and propose a new effective oral rehydration method that can be used daily for preventing dehydration. We first evaluated the effects of different concentrations of milk protein on fluid retention by measuring the urinary volumes of rats fed fluid containing milk protein at concentrations of 1, 5, and 10%. We next compared the fluid-retention effect of milk protein-enriched drink (MPD) with those of distilled water (DW) and a sports drink (SD) by the same method. Third, to investigate the mechanism of fluid retention, we measured plasma insulin changes in rats after ingesting these three drinks. We found that the addition of milk protein at 5 or 10% reduced urinary volume in a dose-dependent manner. Ingestion of the MPD containing 4.6% milk protein resulted in lower urinary volumes than DW and SD. MPD also showed a higher water reabsorption rate in the kidneys and higher concentrations of plasma insulin than DW and SD. These results suggest that increasing milk protein concentration in a beverage enhances fluid retention, which may allow the possibility to develop rehydration beverages that are more effective than SDs. In addition, insulin-modifying renal water reabsorption may contribute to the fluid-retention effect of MPD.

Effects of intravenous bumetanide administration on renal haemodynamics and proximal and distal tubular sodium reabsorption in conscious rats

Energy Technology Data Exchange (ETDEWEB)

Shalmi, M.; Petersen, J.S.; Christensen, S. (Department of pharmacology, University of Copenhagen (Denmark))

1989-01-01

The renal effects of 0.02-62.5 mg/kg bumetanide given as intravenous bolus injections were studied in water diuretic conscious rats. Clearances of {sup 14}C-tetraethylammonium, {sup 3}H-inulin and lithium were used as markers for renal plasma flow (RPF), glomerular filtion rate (GFR) and proximal tubular output, respectively. Bumetanide caused biphasic, transient and dose-independent changes in the renal haemodynamics without significant alterations of the filtration fraction. At dose-levels above 0.02 mg/kg bumetanide increased urine flow, absolute and fractional Na excretion as well as the indices for fractional output of Na from the proximal tubules (C{sub Li}/C{sub I}n) and the distal nephron segments (C{sub Na}/C{sub Li}). The changes in C{sub Li}/C{sub In} became maximal at doses above 0.5 mg/kg, whereas C{sub Na}/C{sub Li} was increased with the dose up to 12.5 mg/kg. Paradoxically, doses above 12.5 mg/kg were less natriuretic due to a decrease of C{sub Na}/C{sub Li}. It is concluded that in rats bumetanide is an effective although short-acting diuretic when administered intravenously. When comparing peak responses bumetanide is equipotent to furosemide but has a lower maximal efficacy. Judged from the changes in fractional lithium excretion, the natriuretic effect of bumetanide is effected by inhibition of Na reabsorption in the proximal tubule in addition to the well-known effect on the distal nephron segment. (author).

Renal handling of sodium and water in the hypothyroid rat

Science.gov (United States)

Michael, Ulrich F.; Barenberg, Robert L.; Chavez, Rafaelita; Vaamonde, Carlos A.; Papper, Solomon

1972-01-01

Hypothyroid rats were examined with conventional renal clearance and micropuncture techniques to elicit the mechanism and site within the nephron responsible for the increased salt and water excretion observed in these animals. When compared with age-matched control rats, a decrease in inulin clearance of 30% (P < 0.001) and in Hippuran clearance of 32% (P < 0.005) was observed in the hypothyroid rats. Absolute excretion of sodium and water was increased 3-fold (P < 0.02) and 2-fold (P < 0.025), respectively, while fractional excretion of sodium and water was increased 4.3-fold (P < 0.02) and 2.9-fold (P < 0.05), respectively, in the hypothyroid animals. Fractional proximal reabsorption of sodium as assessed from proximal tubular fluid to plasma ratios of inulin ([TF/P]IN) was found to be decreased by 28% (P < 0.001) in the hypothyroid rats. Superficial single nephron filtration rate was reduced proportionately to the decrease in total filtration rate in the hypothyroid rats. These data indicate that the proximal tubule is one of the sites of diminished sodium and water reabsorption in the hypothyroid rat. The data also suggest that the observed decrease in glomerular filtration rate in the hypothyroid animals is not caused by a decrease in the number of functioning nephrons and that the observed increase in sodium and water excretion is not caused by a redistribution of filtrate from juxtamedullary to superficial nephrons. Although the exact mechanisms of the observed changes in proximal tubular function remain unknown, the data suggest that they are probably related to the lack of thyroid hormone. Whatever their mechanism, it appears that the enhanced sodium and water excretion observed in the hypothyroid animals must be determined by further reduction in tubular sodium reabsorption in the distal nephron. PMID:5024038

Mobilization and removing of cadmium from kidney by GMDTC utilizing renal glucose reabsorption pathway

International Nuclear Information System (INIS)

Tang, Xiaojiang; Zhu, Jinqiu; Zhong, Zhiyong; Luo, Minhui; Li, Guangxian; Gong, Zhihong; Zhang, Chenzi; Fei, Fan; Ruan, Xiaolin; Zhou, Jinlin; Liu, Gaofeng; Li, Guoding; Olson, James; Ren, Xuefeng

2016-01-01

Chronic exposure to cadmium compounds (Cd 2+ ) is one of the major public health problems facing humans in the 21st century. Cd 2+ in the human body accumulates primarily in the kidneys which leads to renal dysfunction and other adverse health effects. Efforts to find a safe and effective drug for removing Cd 2+ from the kidneys have largely failed. We developed and synthesized a new chemical, sodium (S)-2-(dithiocarboxylato((2S,3R,4R,5R)-2,3,4,5,6 pentahydroxyhexyl)amino)-4-(methylthio) butanoate (GMDTC). Here we report that GMDTC has a very low toxicity with an acute lethal dose (LD50) of more than 10,000 mg/kg or 5000 mg/kg body weight, respectively, via oral or intraperitoneal injection in mice and rats. In in vivo settings, up to 94% of Cd 2+ deposited in the kidneys of Cd 2+ -laden rabbits was removed and excreted via urine following a safe dose of GMDTC treatment for four weeks, and renal Cd 2+ level was reduced from 12.9 μg/g to 1.3 μg/g kidney weight. We observed similar results in the mouse and rat studies. Further, we demonstrated both in in vitro and in animal studies that the mechanism of transporting GMDTC and GMDTC-Cd complex into and out of renal tubular cells is likely assisted by two glucose transporters, sodium glucose cotransporter 2 (SGLT2) and glucose transporter 2 (GLUT2). Collectively, our study reports that GMDTC is safe and highly efficient in removing deposited Cd 2+ from kidneys assisted by renal glucose reabsorption system, suggesting that GMDTC may be the long-pursued agent used for preventive and therapeutic purposes for both acute and chronic Cd 2+ exposure.

Mobilization and removing of cadmium from kidney by GMDTC utilizing renal glucose reabsorption pathway

Energy Technology Data Exchange (ETDEWEB)

Tang, Xiaojiang, E-mail: river-t@126.com [Guangdong Medical Laboratory Animal Center (China); Zhu, Jinqiu [Department of Epidemiology and Environmental Health, The State University of New York, Buffalo, NY (United States); Zhong, Zhiyong; Luo, Minhui; Li, Guangxian [Guangdong Medical Laboratory Animal Center (China); Gong, Zhihong [Department of Epidemiology and Environmental Health, The State University of New York, Buffalo, NY (United States); Zhang, Chenzi; Fei, Fan [Guangdong Medical Laboratory Animal Center (China); Ruan, Xiaolin [Guangdong Poison Control Center (China); Zhou, Jinlin [Golden Health (Foshan) Technology Co., Ltd (China); Liu, Gaofeng [School of Chemistry and Chemical Engineering, Sun Yat-Sen University (China); Li, Guoding [Guangdong Medical Laboratory Animal Center (China); Olson, James [Department of Epidemiology and Environmental Health, The State University of New York, Buffalo, NY (United States); Department of Pharmacology and Toxicology, The State University of New York, Buffalo, NY (United States); Ren, Xuefeng, E-mail: xuefengr@buffalo.edu [Guangdong Medical Laboratory Animal Center (China); Department of Epidemiology and Environmental Health, The State University of New York, Buffalo, NY (United States); Department of Pharmacology and Toxicology, The State University of New York, Buffalo, NY (United States)

2016-08-15

Chronic exposure to cadmium compounds (Cd{sup 2+}) is one of the major public health problems facing humans in the 21st century. Cd{sup 2+} in the human body accumulates primarily in the kidneys which leads to renal dysfunction and other adverse health effects. Efforts to find a safe and effective drug for removing Cd{sup 2+} from the kidneys have largely failed. We developed and synthesized a new chemical, sodium (S)-2-(dithiocarboxylato((2S,3R,4R,5R)-2,3,4,5,6 pentahydroxyhexyl)amino)-4-(methylthio) butanoate (GMDTC). Here we report that GMDTC has a very low toxicity with an acute lethal dose (LD50) of more than 10,000 mg/kg or 5000 mg/kg body weight, respectively, via oral or intraperitoneal injection in mice and rats. In in vivo settings, up to 94% of Cd{sup 2+} deposited in the kidneys of Cd{sup 2+}-laden rabbits was removed and excreted via urine following a safe dose of GMDTC treatment for four weeks, and renal Cd{sup 2+} level was reduced from 12.9 μg/g to 1.3 μg/g kidney weight. We observed similar results in the mouse and rat studies. Further, we demonstrated both in in vitro and in animal studies that the mechanism of transporting GMDTC and GMDTC-Cd complex into and out of renal tubular cells is likely assisted by two glucose transporters, sodium glucose cotransporter 2 (SGLT2) and glucose transporter 2 (GLUT2). Collectively, our study reports that GMDTC is safe and highly efficient in removing deposited Cd{sup 2+} from kidneys assisted by renal glucose reabsorption system, suggesting that GMDTC may be the long-pursued agent used for preventive and therapeutic purposes for both acute and chronic Cd{sup 2+} exposure.

Towards a system-based pharmacology approach to predict developmental changes in renal drug clearance in children

NARCIS (Netherlands)

De Cock, Roosmarijn Frieda Wilfried

2014-01-01

Renal clearance is responsible for the elimination of a large number of water-soluble drugs and metabolites and is therefore of large importance when characterizing the pharmacokinetics of drugs. Renal clearance includes glomerular filtration, tubular secretion and reabsorption and each of these

Validation of phenol red versus gravimetric method for water reabsorption correction and study of gender differences in Doluisio's absorption technique.

Science.gov (United States)

Tuğcu-Demiröz, Fatmanur; Gonzalez-Alvarez, Isabel; Gonzalez-Alvarez, Marta; Bermejo, Marival

2014-10-01

The aim of the present study was to develop a method for water flux reabsorption measurement in Doluisio's Perfusion Technique based on the use of phenol red as a non-absorbable marker and to validate it by comparison with gravimetric procedure. The compounds selected for the study were metoprolol, atenolol, cimetidine and cefadroxil in order to include low, intermediate and high permeability drugs absorbed by passive diffusion and by carrier mediated mechanism. The intestinal permeabilities (Peff) of the drugs were obtained in male and female Wistar rats and calculated using both methods of water flux correction. The absorption rate coefficients of all the assayed compounds did not show statistically significant differences between male and female rats consequently all the individual values were combined to compare between reabsorption methods. The absorption rate coefficients and permeability values did not show statistically significant differences between the two strategies of concentration correction. The apparent zero order water absorption coefficients were also similar in both correction procedures. In conclusion gravimetric and phenol red method for water reabsorption correction are accurate and interchangeable for permeability estimation in closed loop perfusion method. Copyright © 2014 Elsevier B.V. All rights reserved.

Demeclocycline Attenuates Hyponatremia by Reducing Aquaporin-2 Expression in the Renal Inner Medulla

DEFF Research Database (Denmark)

Kortenoeven, Marleen L. A.; Sinke, Anne P.; Hadrup, Niels

2013-01-01

Binding of vasopressin to its type-2 receptor in renal collecting ducts induces cAMP signaling, transcription and translocation of aquaporin-2 (AQP2) water channels to the plasma membrane and water reabsorption from the pro-urine. Demeclocycline is currently used to treat hyponatremia in patients...

Renal albumin absorption in physiology and pathology.

Science.gov (United States)

Birn, H; Christensen, E I

2006-02-01

Albumin is the most abundant plasmaprotein serving multiple functions as a carrier of metabolites, hormones, vitamins, and drugs, as an acid/base buffer, as antioxidant and by supporting the oncotic pressure and volume of the blood. The presence of albumin in urine is considered to be the result of the balance between glomerular filtration and tubular reabsorption. Albuminuria has been accepted as an independent risk factor and a marker for renal as well as cardiovascular disease, and during the past decade, evidence has suggested that albumin itself may cause progression of renal disease. Thus, the reduction of proteinuria and, in particular, albuminuria has become a target in itself to prevent deterioration of renal function. Studies have shown albumin and its ligands to induce expression of inflammatory and fibrogenic mediators, and it has been hypothesized that increased filtration of albumin causes excessive tubular reabsorption, resulting in inflammation and fibrosis, resulting in the loss of renal function. In addition, it is known that tubular dysfunction in itself may cause albuminuria owing to decreased reabsorption of filtered albumin, and, recently, it has been suggested that significant amounts of albumin fragments are excreted in the urine as a result of tubular degradation. Thus, although both tubular and glomerular dysfunction influences renal handling of albumin, it appears that tubular reabsorption plays a central role in mediating the effects of albumin on renal function. The present paper will review the mechanisms for tubular albumin uptake and the possible implications for the development of renal disease.

Effect of Cuscuta chinensis on renal function in ischemia/reperfusion-induced acute renal failure rats.

Science.gov (United States)

Shin, Sun; Lee, Yun Jung; Kim, Eun Ju; Lee, An Sook; Kang, Dae Gill; Lee, Ho Sub

2011-01-01

The kidneys play a central role in regulating water, ion composition and excretion of metabolic waste products in the urine. Cuscuta chinensis has been known as an important traditional Oriental medicine for the treatment of liver and kidney disorders. Thus, we studied whether an aqueous extract of Cuscuta chinensis (ACC) seeds has an effect on renal function parameters in ischemia/reperfusion-induced acute renal failure (ARF) rats. Administration of 250 mg/kg/day ACC showed that renal functional parameters including urinary excretion rate, osmolality, Na(+), K(+), Cl(-), creatinine clearance, solute-free water reabsorption were significantly recovered in ischemia/reperfusion-induced ARF. Periodic acid Schiff staining showed that administration of ACC improved tubular damage in ischemia/reperfusion-induced ARF. In immunoblot and immunohistological examinations, ischemia/reperfusion-induced ARF decreased the expressions of water channel AQP 2, 3 and sodium potassium pump Na,K-ATPase in the renal medulla. However, administration of ACC markedly incremented AQP 2, 3 and Na,K-ATPase expressions. Therefore, these data indicate that administration of ACC ameliorates regulation of the urine concentration and renal functions in rats with ischemia/reperfusion-induced ARF.

Regulation of renal NaPi-2 expression and tubular phosphate reabsorption by growth hormone in the juvenile rat.

Science.gov (United States)

Woda, Craig B; Halaihel, Nabil; Wilson, Paul V; Haramati, Aviad; Levi, Moshe; Mulroney, Susan E

2004-07-01

Growth hormone (GH) is an important factor in the developmental adaptation to enhance P(i) reabsorption; however, the nephron sites and mechanisms by which GH regulates renal P(i) uptake remain unclear and are the focus of the present study. Micropuncture experiments were performed after acute thyroparathyroidectomy in the presence and absence of parathyroid hormone (PTH) in adult (14- to 17-wk old), juvenile (4-wk old), and GH-suppressed juvenile male rats. While the phosphaturic effect of PTH was blunted in the juvenile rat compared with the adult, suppression of GH in the juvenile restored fractional P(i) excretion to adult levels. In the presence or absence of PTH, GH suppression in the juvenile rat caused a significant increase in the fractional P(i) delivery to the late proximal convoluted (PCT) and early distal tubule, so that delivery was not different from that in adults. These data were confirmed by P(i) uptake studies into brush-border membrane (BBM) vesicles. Immunofluorescence studies indicate increased BBM type IIa NaP(i) cotransporter (NaPi-2) expression in the juvenile compared with adult rat, and GH suppression reduced NaPi-2 expression to levels observed in the adult. GH replacement in the [N-acetyl-Tyr(1)-d-Arg(2)]-GRF-(1-29)-NH(2)-treated juveniles restored high NaPi-2 expression and P(i) uptake. Together, these novel results demonstrate that the presence of GH in the juvenile animal is crucial for the early developmental upregulation of BBM NaPi-2 and, most importantly, describe the enhanced P(i) reabsorption along the PCT and proximal straight nephron segments in the juvenile rat.

Effect of cisplatin on renal haemodynamics and tubular function in the dog kidney

DEFF Research Database (Denmark)

Daugaard, G; Abildgaard, U; Holstein-Rathlou, N H

1987-01-01

Administration of cisplatin (5 mg/kg) to dogs results in polyuric renal failure due initially to a proximal tubular functional impairment. 48-72 h after the cisplatin administration the depressed renal function can be attributed to impairment of proximal as well as distal tubular reabsorptive cap...... capacities associated with increased renal vascular resistance. The polyuria seems to be due to the impaired reabsorption rate in the distal nephron segments....

Renal vein oxygen saturation in renal artery stenosis

DEFF Research Database (Denmark)

Nielsen, K; Rehling, M; Henriksen, Jens Henrik Sahl

1992-01-01

Renal vein oxygen-saturation was measured in 56 patients with arterial hypertension and unilateral stenosis or occlusion of the renal artery. Oxygen-saturation in blood from the ischaemic kidney (84.4%, range 73-93%) was significantly higher than that from the 'normal' contralateral kidney (81...... than its blood flow. This is probably due to decreased filtration fraction and filtered sodium with subsequent reduction in absolute tubular re-absorption of sodium ions....

Paracellular transport and energy utilization in the renal tubule.

Science.gov (United States)

Yu, Alan S L

2017-09-01

Paracellular transport across the tight junction is a general mechanism for transepithelial transport of solutes in epithelia, including the renal tubule. However, why paracellular transport evolved, given the existence of a highly versatile system for transcellular transport, is unknown. Recent studies have identified the paracellular channel, claudin-2, that is responsible for paracellular reabsorption of sodium in the proximal renal tubule. Knockout of claudin-2 in mice impairs proximal sodium and fluid reabsorption but is compensated by upregulation of sodium reabsorption in the loop of Henle. This occurs at the expense of increased renal oxygen consumption, hypoxia of the outer medulla and increased susceptibility to ischemic kidney injury. Paracellular transport can be viewed as a mechanism to exploit the potential energy in existing electrochemical gradients to drive passive transepithelial transport without consuming additional energy. In this way, it enhances the efficiency of energy utilization by transporting epithelia.

Distribution of glucose transporters in renal diseases

OpenAIRE

Szablewski, Leszek

2017-01-01

Kidneys play an important role in glucose homeostasis. Renal gluconeogenesis prevents hypoglycemia by releasing glucose into the blood stream. Glucose homeostasis is also due, in part, to reabsorption and excretion of hexose in the kidney. Lipid bilayer of plasma membrane is impermeable for glucose, which is hydrophilic and soluble in water. Therefore, transport of glucose across the plasma membrane depends on carrier proteins expressed in the plasma membrane. In humans, there are three famil...

Gastrointestinal and renal responses to variable water intake in whitebellied sunbirds and New Holland honeyeaters.

Science.gov (United States)

Purchase, Cromwell; Napier, Kathryn R; Nicolson, Susan W; McWhorter, Todd J; Fleming, Patricia A

2013-05-01

Nectarivores face a constant challenge in terms of water balance, experiencing water loading or dehydration when switching between food plants or between feeding and fasting. To understand how whitebellied sunbirds and New Holland honeyeaters meet the challenges of varying preformed water load, we used the elimination of intramuscular-injected [(14)C]-l-glucose and (3)H2O to quantify intestinal and renal water handling on diets varying in sugar concentration. Both sunbirds and honeyeaters showed significant modulation of intestinal water absorption, allowing excess water to be shunted through the intestine when on dilute diets. Despite reducing their fractional water absorption, both species showed linear increases in water flux and fractional body water turnover as water intake increased (both afternoon and morning), suggesting that the modulation of fractional water absorption was not sufficient to completely offset dietary water loads. In both species, glomerular filtration rate was independent of water gain (but was higher for the afternoon), as was renal fractional water reabsorption (measured in the afternoon). During the natural overnight fast, both sunbirds and honeyeaters arrested whole kidney function. Evaporative water loss in sunbirds was variable but correlated with water gain. Both sunbirds and honeyeaters appear to modulate intestinal water absorption as an important component of water regulation to help deal with massive preformed water loads. Shutting down glomerular filtration rate during the overnight fast is another way of saving energy for osmoregulatory function. Birds maintain osmotic balance on diets varying markedly in preformed water load by varying both intestinal water absorption and excretion through the intestine and kidneys.

Recombinant erythropoietin acutely decreases renal perfusion and decouples the renin-angiotensin-aldosterone system.

Science.gov (United States)

Aachmann-Andersen, Niels J; Christensen, Soren J; Lisbjerg, Kristian; Oturai, Peter; Johansson, Pär I; Holstein-Rathlou, Niels-Henrik; Olsen, Niels V

2018-03-01

The effect of recombinant erythropoietin (rhEPO) on renal and systemic hemodynamics was evaluated in a randomized double-blinded, cross-over study. Sixteen healthy subjects were tested with placebo, or low-dose rhEPO for 2 weeks, or high-dose rhEPO for 3 days. Subjects refrained from excessive salt intake, according to instructions from a dietitian. Renal clearance studies were done for measurements of renal plasma flow, glomerular filtration rate (GFR) and the segmentel tubular handling of sodium and water (lithium clearance). rhEPO increased arterial blood pressure, total peripheral resistance, and renal vascular resistance, and decreased renal plasma flow in the high-dose rhEPO intervention and tended to decrease GFR. In spite of the decrease in renal perfusion, rhEPO tended to decrease reabsorption of sodium and water in the proximal tubule and induced a prompt decrease in circulating levels of renin and aldosterone, independent of changes in red blood cell mass, blood volumes, and blood pressure. We also found changes in biomarkers showing evidence that rhEPO induced a prothrombotic state. Our results suggest that rhEPO causes a direct downregulation in proximal tubular reabsorption that seems to decouple the activity of the renin-angiotensin-aldosterone system from changes in renal hemodynamics. This may serve as a negative feed-back mechanism on endogenous synthesis of EPO when circulating levels of EPO are high. These results demonstrates for the first time in humans a direct effect of rhEPO on renal hemodynamics and a decoupling of the renin-angiotensin-aldosterone system. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock.

Science.gov (United States)

Skytte Larsson, Jenny; Krumbholz, Vitus; Enskog, Anders; Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2018-06-01

Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Prospective comparative study. General and cardiothoracic ICUs. Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). None. Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.

Sodium glucose co-transporter 2 inhibitors: blocking renal tubular reabsorption of glucose to improve glycaemic control in patients with diabetes.

Science.gov (United States)

Jabbour, S A; Goldstein, B J

2008-08-01

The kidney plays a central role in the regulation of plasma glucose levels, although until recently this has not been widely appreciated or considered a target for therapeutic intervention. The sodium glucose co-transporter type 2 (SGLT2) located in the plasma membrane of cells lining the proximal tubule mediates the majority of renal glucose reabsorption from the tubular fluid, which normally prevents the loss of glucose in the urine. Competitive inhibitors of SGLT2 that provoke the renal excretion of glucose have been discovered, thereby providing a unique mechanism to potentially lower the elevated blood glucose levels in patients with diabetes. To explore the physiology of SGLT2 action and discuss several SGLT2 inhibitors that have entered early clinical development. All publicly available data were identified by searching the internet for 'SGLT2' and 'SGLT2 inhibitor' through 1 November 2007. Published articles, press releases and abstracts presented at national and international meetings were considered. Sodium glucose co-transporter type 2 inhibition is a novel treatment option for diabetes, which has been studied in preclinical models and a few potent and selective SGLT2 inhibitors have been reported and are currently in clinical development. These agents appear to be safe and generally well tolerated, and will potentially be a beneficial addition to the growing battery of oral antihyperglycaemic agents.

Renal Control of Calcium, Phosphate, and Magnesium Homeostasis

Science.gov (United States)

Chonchol, Michel; Levi, Moshe

2015-01-01

Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys. PMID:25287933

Renoprotective Effects of SGLT2 Inhibitors: Beyond Glucose Reabsorption Inhibition.

Science.gov (United States)

Tsimihodimos, V; Filippatos, T D; Filippas-Ntekouan, S; Elisaf, M

2017-01-01

Sodium-glucose co-transporter 2 (SGLT2) inhibitors are a new class of antidiabetic drugs that inhibit glucose and sodium reabsorption at proximal tubules. These drugs may exhibit renoprotective properties, since they prevent the deterioration of the glomerular filtration rate and reduce the degree of albuminuria in patients with diabetes-associated kidney disease. In this review we consider the pathophysiologic mechanisms that have been recently implicated in the renoprotective properties of SGLT2 inhibitors. The beneficial effects of SGLT2 inhibitors on the conventional risk factors for kidney disease (such as blood pressure, hyperglycaemia, body weight and serum uric acid levels) may explain, at least in part, the observed renal-protecting properties of these compounds. However, it has been hypothesized that the most important mechanisms for this phenomenon include the reduction in the intraglomerular pressure, the changes in the local and systemic degree of activation of the renin-aldosterone-angiotensin system and a shift in renal fuel consumption towards more efficient energy substrates such as ketone bodies. The beneficial effects of SGLT2 inhibitors on various aspects of renal function make them an attractive choice in patients with (and possibly without) diabetes-associated renal impairment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Technique of experimental measurements of the optical thickness of a pulse discharge plasma channel in water on a contour reabsorption lines of hydrogen Hα

Directory of Open Access Journals (Sweden)

O. A. Fedorovich

2010-03-01

Full Text Available In this work the results of development and application of the technique of experimental definition of optical thickness (τ of the pulse discharge plasma channel in water which are based on the distribution of radiation intensities on contour reabsorption lines of hydrogen Ha (656.3 nm are given. Optical thickness of continues spectrum was defined by extrapolation of intensities in far wing of contour reabsorption lines of hydrogen Ha, where t value did not vary any more, and the line smoothly transferred in continuous spectrum. The atomic concentration Na, received on a method of definition of t on a contour reabsorption lines of hydrogen Ha., agreed with calculation obtained from the equation of the plasma state. The recommendations on the correct definition of optical thickness of plasma of pulse discharge in liquids are given.

Effects of positive end-expiratory pressure on renal function.

Science.gov (United States)

Järnberg, P O; de Villota, E D; Eklund, J; Granberg, P O

1978-01-01

The effects were studied positive end-expiratory pressure (PEEP) on renal function in eight patients with acute respiratory failure, requiring mechanical ventilation. On application of PEEP + 10 cm H2O, central venous pressure increased, systolic blood pressure decreased, urine flow and PAH-clearance were reduced, while inulin clearance remained stable. There was a marked increase in fractional sodium reabsorption and a concurrent decrease in fractional osmolal excretion. Fractional free-water clearance and the ratio UOsm/POsm did change.

Inhibition of renal Na+/H+ exchange in cadmium-intoxicated rats

International Nuclear Information System (INIS)

Ahn, Do Whan; Chung, Jin Mo; Kim, Jee Yeun; Kim, Kyoung Ryong; Park, Yang Saeng

2005-01-01

Chronic exposure to cadmium (Cd) results in bicarbonaturia, leading to metabolic acidosis. To elucidate the mechanism(s) by which renal bicarbonate reabsorption is inhibited, we investigated changes in renal transporters and enzymes associated with bicarbonate reabsorption in Cd-intoxicated rats. Cd intoxication was induced by subcutaneous injections of CdCl 2 (2 mg Cd/kg per day) for 3 weeks. Cd intoxication resulted in a significant reduction in V max of Na + /H + antiport with no changes in K Na in the renal cortical brush-border membrane vesicles (BBMV). Western blotting of BBM proteins and indirect immunohistochemistry in renal tissue sections, using an antibody against Na + /H + exchange-3 (NHE3), showed a diminished expression of NHE3 protein in the BBM. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that NHE3 mRNA expression was reduced in the renal cortex. The activity of carbonic anhydrase IV (CA IV) in BBM was not changed. The protein abundance of Na + -HCO 3 - cotransporter-1 (NBC1) in whole kidney membrane fractions was slightly attenuated, whereas that of the Na + -K + -ATPase α-subunit was markedly elevated in Cd-intoxicated animals. These results indicate that Cd intoxication impairs NHE3 expression in the proximal tubule, thereby reducing the capacity for bicarbonate reabsorption, leading to bicarbonaturia in an intact animal

Response of copper deficient rats to inhibitors of renal sodium reabsorption

Energy Technology Data Exchange (ETDEWEB)

Noordewier, B.; Saari, J.T. (Northwestern College, Orange City, IA (United States) USDA/ARS, Grand Forks, ND (United States))

1991-03-11

This study examined the effects of furosemide (Furo), a Loop diuretic, and amiloride (Am), a potassium (K)-sparing diuretic, on the excretion of sodium (Na) and K in copper-adequate (CuAdeq) and copper-deficient (CuDef) rats. Weanling male Sprague Dawley rats were fed a CuDef or CuAdeq diet ad libitum and given deionized water to drink. After 5 weeks on the diets, rats were assigned to one of four treatment regimens: Furo, Am or Furo + Am. Rats were anesthetized and electrolyte excretion was measured in 2 {times} 15 min control periods followed by 3 {times} 15 min treatment periods. Furo increased Na excretion in a dose dependent manner in both the CuAdeq and the CuDef rats. The response of the CuAdeq rats was slightly greater than that of the CuDef rats in each of the 3 treatment groups in which Furo was given. K excretion following Furo increased to the same extent in the CuAdeq and CuDef rats. The natriuretic response to Am alone was slightly greater in the CuDef than the CuAdeq rats. The antikaliuretic response of the CuDef rats was similar to that of the CuAdeq rats whether Am was given alone or in combination with Furo. These data show that CuDef rats respond to Furo and Am in a manner which is similar to that of CuAdeq rats, this indicates that the sensitivity of the Na reabsorption mechanisms to inhibition by diuretics is not markedly affected by copper deficiency.

Roles of renal ammonia metabolism other than in acid-base homeostasis.

Science.gov (United States)

Weiner, I David

2017-06-01

The importance of renal ammonia metabolism in acid-base homeostasis is well known. However, the effects of renal ammonia metabolism other than in acid-base homeostasis are not as widely recognized. First, ammonia differs from almost all other solutes in the urine in that it does not result from arterial delivery. Instead, ammonia is produced by the kidney, and only a portion of the ammonia produced is excreted in the urine, with the remainder returned to the systemic circulation through the renal veins. In normal individuals, systemic ammonia addition is metabolized efficiently by the liver, but in patients with either acute or chronic liver disease, conditions that increase the addition of ammonia of renal origin to the systemic circulation can result in precipitation and/or worsening of hyperammonemia. Second, ammonia appears to serve as an intrarenal paracrine signaling molecule. Hypokalemia increases proximal tubule ammonia production and secretion as well as reabsorption in the thick ascending limb of the loop of Henle, thereby increasing delivery to the renal interstitium and the collecting duct. In the collecting duct, ammonia decreases potassium secretion and stimulates potassium reabsorption, thereby decreasing urinary potassium excretion and enabling feedback correction of the initiating hypokalemia. Finally, the stimulation of renal ammonia metabolism by hypokalemia may contribute to the development of metabolic alkalosis, which in turn can stimulate NaCl reabsorption and contribute to the intravascular volume expansion, increased blood pressure and diuretic resistance that can develop with hypokalemia. The evidence supporting these novel non-acid-base roles of renal ammonia metabolism is discussed in this review.

Recombinant human erythropoietin in humans down-regulates proximal renal tubular reabsorption and causes a fall in glomerular filtration rate

DEFF Research Database (Denmark)

Olsen, Niels Vidiendal; Aachmann-Andersen, Niels Jacob; Oturai, Peter

2010-01-01

HuEPO for 28 days in doses raising the hematocrit to 48.3 (4.1) %. Renal clearance studies with urine collections (N = 8) were done at baseline and at days 4, 11, 29, and 42. Glomerular filtration rate (GFR) was measured by (51)Cr-EDTA. Renal clearance of lithium (C(Li)) was used as an index of proximal...... tubular outflow and to assess segmental renal tubular handling of sodium and water. rHuEPO-induced increases in hematocrit occurred from day 10 onwards and was caused by both an increase in red cell volume and a fall in plasma volume. Well before that (from day 2 and throughout the treatment time), r...... and water (APR = GFR - C(Li), P

Renal morphology of Bradypus torquatus

Directory of Open Access Journals (Sweden)

Pedro Kastein Faria da Cunha Bianchi

2012-11-01

Full Text Available Among the Xenarthras, sloths present a hydric ingestion restricted to water from leaves, fruits, and vegetables. As a first approach to verify whether these animals have some morphophysiological difference which could justify or compensate this low hydric ingestion, the renal anatomy of these animals was investigated, particularly that of maned sloth (Bradypus torquatus. Kidneys from these animals were macroscopically analyzed, through light microscopy and scanning electron microscopy. The Bradypus torquatus kidneys are bean-shaped paired organs, located dorso-cranially to the pelvic girdle, between the peritoneum and the posterior abdominal wall. The use of histological techniques allowed us to identify, in the cortical region, the renal corpuscles and tubules, and, in the medullary region, a significant amount of interstitial tissue with a collecting duct. The results of this study showed that, although Bradypus torquatus doesn’t drink water directly, its kidneys doesn’t differ from that of most mammals, presenting the same anatomical structure, suggesting that these animals fully reach their hydric needs, basically by consuming leaves, fruits, and sprouts. Nevertheless, in order to confirm this hypothesis, studies on the effectiveness of water reabsorption, such as the renin-angiotensin-aldosterone system, must be carried out.

Hypocapnic but not metabolic alkalosis impairs alveolar fluid reabsorption.

Science.gov (United States)

Myrianthefs, Pavlos M; Briva, Arturo; Lecuona, Emilia; Dumasius, Vidas; Rutschman, David H; Ridge, Karen M; Baltopoulos, George J; Sznajder, Jacob Iasha

2005-06-01

Acid-base disturbances, such as metabolic or respiratory alkalosis, are relatively common in critically ill patients. We examined the effects of alkalosis (hypocapnic or metabolic alkalosis) on alveolar fluid reabsorption in the isolated and continuously perfused rat lung model. We found that alveolar fluid reabsorption after 1 hour was impaired by low levels of CO2 partial pressure (PCO2; 10 and 20 mm Hg) independent of pH levels (7.7 or 7.4). In addition, PCO2 higher than 30 mm Hg or metabolic alkalosis did not have an effect on this process. The hypocapnia-mediated decrease of alveolar fluid reabsorption was associated with decreased Na,K-ATPase activity and protein abundance at the basolateral membranes of distal airspaces. The effect of low PCO2 on alveolar fluid reabsorption was reversible because clearance normalized after correcting the PCO2 back to normal levels. These data suggest that hypocapnic but not metabolic alkalosis impairs alveolar fluid reabsorption. Conceivably, correction of hypocapnic alkalosis in critically ill patients may contribute to the normalization of lung ability to clear edema.

Reactive Oxygen Species Modulation of Na/K-ATPase Regulates Fibrosis and Renal Proximal Tubular Sodium Handling

Directory of Open Access Journals (Sweden)

Jiang Liu

2012-01-01

Full Text Available The Na/K-ATPase is the primary force regulating renal sodium handling and plays a key role in both ion homeostasis and blood pressure regulation. Recently, cardiotonic steroids (CTS-mediated Na/K-ATPase signaling has been shown to regulate fibrosis, renal proximal tubule (RPT sodium reabsorption, and experimental Dahl salt-sensitive hypertension in response to a high-salt diet. Reactive oxygen species (ROS are an important modulator of nephron ion transport. As there is limited knowledge regarding the role of ROS-mediated fibrosis and RPT sodium reabsorption through the Na/K-ATPase, the focus of this review is to examine the possible role of ROS in the regulation of Na/K-ATPase activity, its signaling, fibrosis, and RPT sodium reabsorption.

Hereditary tubular transport disorders: implications for renal handling of Ca2+ and Mg2+.

NARCIS (Netherlands)

Dimke, H.; Hoenderop, J.G.J.; Bindels, R.J.M.

2010-01-01

The kidney plays an important role in maintaining the systemic Ca2+ and Mg2+ balance. Thus the renal reabsorptive capacity of these cations can be amended to adapt to disturbances in plasma Ca2+ and Mg2+ concentrations. The reabsorption of Ca2+ and Mg2+ is driven by transport of other electrolytes,

Testosterone increases urinary calcium excretion and inhibits expression of renal calcium transport proteins.

NARCIS (Netherlands)

Hsu, Y.J.; Dimke, H.; Schoeber, J.P.H.; Hsu, S.C.; Lin, S.H.; Chu, P.; Hoenderop, J.G.J.; Bindels, R.J.M.

2010-01-01

Although gender differences in the renal handling of calcium have been reported, the overall contribution of androgens to these differences remains uncertain. We determined here whether testosterone affects active renal calcium reabsorption by regulating calcium transport proteins. Male mice had

H+, Water and Urea Transport in the Inner Medullary Collecting Duct and Their Role in the Prevention and Pathogenesis of Renal Stone Disease

Science.gov (United States)

Wall, Susan M.; Klein, Janet D.

2008-09-01

The inner medullary collecting duct (IMCD) is the final site within the kidney for the reabsorption of urea, water and electrolytes and for the secretion of H+ before the luminal fluid becomes the final urine. Transporters expressed in the IMCD contribute to the generation of the large ion gradients that exist between the interstitium and the collecting duct lumen. Thus, the luminal fluid within the human IMCD can reach an osmolality of 1200 mOsm/kg H2O and a pH of 4. This ability of the human nephron to concentrate and acidify the urine might predispose to stone formation. However, under treatment conditions that predispose to stone formation, such as during hypercalciuria, the kidney mitigates stone formation by reducing solute concentration by reducing H2O reabsorption. Moreover, the kidney attenuates stone formation by tightly controlling acid-base balance, which prevents the bone loss, hypocitraturia and hypercalciuria observed during metabolic acidosis by augmenting net H+ excretion by tightly regulating H+ transporter function and through luminal buffering, particularly with NH3. This article will review the ion transporters present in the mammalian IMCD and their role in the prevention and in the pathogenesis of renal stone formation.

Albumin-derived peptides efficiently reduce renal uptake of radiolabelled peptides

International Nuclear Information System (INIS)

Vegt, Erik; Eek, Annemarie; Oyen, Wim J.G.; Gotthardt, Martin; Boerman, Otto C.; Jong, Marion de

2010-01-01

In peptide-receptor radionuclide therapy (PRRT), the maximum activity dose that can safely be administered is limited by high renal uptake and retention of radiolabelled peptides. The kidney radiation dose can be reduced by coinfusion of agents that competitively inhibit the reabsorption of radiolabelled peptides, such as positively charged amino acids, Gelofusine, or trypsinised albumin. The aim of this study was to identify more specific and potent inhibitors of the kidney reabsorption of radiolabelled peptides, based on albumin. Albumin was fragmented using cyanogen bromide and six albumin-derived peptides with different numbers of electric charges were selected and synthesised. The effect of albumin fragments (FRALB-C) and selected albumin-derived peptides on the internalisation of 111 In-albumin, 111 In-minigastrin, 111 In-exendin and 111 In-octreotide by megalin-expressing cells was assessed. In rats, the effect of Gelofusine and albumin-derived peptides on the renal uptake and biodistribution of 111 In-minigastrin, 111 In-exendin and 111 In-octreotide was determined. FRALB-C significantly reduced the uptake of all radiolabelled peptides in vitro. The albumin-derived peptides showed different potencies in reducing the uptake of 111 In-albumin, 111 In-exendin and 111 In-minigastrin in vitro. The most efficient albumin-derived peptide (peptide 6), was selected for in vivo testing. In rats, 5 mg of peptide 6 very efficiently inhibited the renal uptake of 111 In-minigastrin, by 88%. Uptake of 111 In-exendin and 111 In-octreotide was reduced by 26 and 33%, respectively. The albumin-derived peptide 6 efficiently inhibited the renal reabsorption of 111 In-minigastrin, 111 In-exendin and 111 In-octreotide and is a promising candidate for kidney protection in PRRT. (orig.)

Observations on the mechanism and location of ascites reabsorption in man

International Nuclear Information System (INIS)

Rector, W.G. Jr.; Ibarra, F.

1987-01-01

Animal data indicate that ascites is reabsorbed by a lymphatic mechanism and that these vessels are subdiaphragmatic in location. We evaluated the relative role of lymphatics in ascites reabsorption in man by comparing the ascites clearance and plasma appearance rates of intraperitoneally injected radiolabeled albumin to those of intraperitoneally injected labeled autologous red blood cells, which require, owing to their large size, lymphatic removal, in patients with cirrhosis and ascites. To evaluate the location of reabsorption, we repeated these measurements after replacing ascites in the subdiaphragmatic region with 500-1000 ml of intraperitoneally injected air, reasoning that this maneuver should slow or eliminate ascites reabsorption occurring at this site. We found that the transfer rates of albumin and red cells out of ascites were similar and that creation of pneumoperitoneum did not influence these rates. These data confirm that ascites protein reabsorption occurs via a lymphatic mechanism in man. They suggest, however, that these vessels may not be subdiaphragmatic in location

Roles of Akt and SGK1 in the Regulation of Renal Tubular Transport

Directory of Open Access Journals (Sweden)

Nobuhiko Satoh

2015-01-01

Full Text Available A serine/threonine kinase Akt is a key mediator in various signaling pathways including regulation of renal tubular transport. In proximal tubules, Akt mediates insulin signaling via insulin receptor substrate 2 (IRS2 and stimulates sodium-bicarbonate cotransporter (NBCe1, resulting in increased sodium reabsorption. In insulin resistance, the IRS2 in kidney cortex is exceptionally preserved and may mediate the stimulatory effect of insulin on NBCe1 to cause hypertension in diabetes via sodium retention. Likewise, in distal convoluted tubules and cortical collecting ducts, insulin-induced Akt phosphorylation mediates several hormonal signals to enhance sodium-chloride cotransporter (NCC and epithelial sodium channel (ENaC activities, resulting in increased sodium reabsorption. Serum- and glucocorticoid-inducible kinase 1 (SGK1 mediates aldosterone signaling. Insulin can stimulate SGK1 to exert various effects on renal transporters. In renal cortical collecting ducts, SGK1 regulates the expression level of ENaC through inhibition of its degradation. In addition, SGK1 and Akt cooperatively regulate potassium secretion by renal outer medullary potassium channel (ROMK. Moreover, sodium-proton exchanger 3 (NHE3 in proximal tubules is possibly activated by SGK1. This review focuses on recent advances in understanding of the roles of Akt and SGK1 in the regulation of renal tubular transport.

Localisation and mechanism of renal retention of radiolabelled somatostatin analogues

Energy Technology Data Exchange (ETDEWEB)

Melis, Marleen; Krenning, Eric P.; Bernard, Bert F.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Barone, Raffaella [UCL, Centre of Nuclear Medicine and Laboratory of PET, Brussels (Belgium); Visser, Theo J. [Erasmus MC, Department of Internal Medicine, Rotterdam (Netherlands)

2005-10-01

Radiolabelled somatostatin analogues, such as octreotide and octreotate, are used for tumour scintigraphy and radionuclide therapy. The kidney is the most important critical organ during such therapy owing to the reabsorption and retention of radiolabelled peptides. The aim of this study was to investigate in a rat model both the localisation and the mechanism of renal uptake after intravenous injection of radiolabelled somatostatin analogues. The multi-ligand megalin/cubilin receptor complex, responsible for reabsorption of many peptides and proteins in the kidney, is an interesting candidate for renal endocytosis of these peptide analogues. For localisation studies, ex vivo autoradiography and micro-autoradiography of rat kidneys were performed 1-24 h after injection of radiolabelled somatostatin analogues and compared with the renal anti-megalin immunohistochemical staining pattern. To confirm a role of megalin in the mechanism of renal retention of [{sup 111}In-DTPA]octreotide, the effects of three inhibitory substances were explored in rats. Renal ex vivo autoradiography showed high cortical radioactivity and lower radioactivity in the outer medulla. The distribution of cortical radioactivity was inhomogeneous. Micro-autoradiography indicated that radioactivity was only retained in the proximal tubules. The anti-megalin immunohistochemical staining pattern showed a strong similarity with the renal [{sup 111}In-DTPA]octreotide ex vivo autoradiograms. Biodistribution studies showed that co-injection of positively charged d-lysine reduced renal uptake to 60% of control. Sodium maleate reduced renal [{sup 111}In-DTPA]octreotide uptake to 15% of control. Finally, cisplatin pre-treatment of rats reduced kidney uptake to 70% of control. Renal retention of [{sup 111}In-DTPA]octreotide is confined to proximal tubules in the rat kidney, in which megalin-mediated endocytosis may play an important part. (orig.)

21 CFR 876.4650 - Water jet renal stone dislodger system.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Water jet renal stone dislodger system. 876.4650... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4650 Water jet renal stone dislodger system. (a) Identification. A water jet renal stone dislodger system is a device used to...

The Trafficking of the Water Channel Aquaporin-2 in Renal Principal Cells—a Potential Target for Pharmacological Intervention in Cardiovascular Diseases

Science.gov (United States)

Vukićević, Tanja; Schulz, Maike; Faust, Dörte; Klussmann, Enno

2016-01-01

Arginine-vasopressin (AVP) stimulates the redistribution of water channels, aquaporin-2 (AQP2) from intracellular vesicles into the plasma membrane of renal collecting duct principal cells. By this AVP directs 10% of the water reabsorption from the 170 L of primary urine that the human kidneys produce each day. This review discusses molecular mechanisms underlying the AVP-induced redistribution of AQP2; in particular, it provides an overview over the proteins participating in the control of its localization. Defects preventing the insertion of AQP2 into the plasma membrane cause diabetes insipidus. The disease can be acquired or inherited, and is characterized by polyuria and polydipsia. Vice versa, up-regulation of the system causing a predominant localization of AQP2 in the plasma membrane leads to excessive water retention and hyponatremia as in the syndrome of inappropriate antidiuretic hormone secretion (SIADH), late stage heart failure or liver cirrhosis. This article briefly summarizes the currently available pharmacotherapies for the treatment of such water balance disorders, and discusses the value of newly identified mechanisms controlling AQP2 for developing novel pharmacological strategies. Innovative concepts for the therapy of water balance disorders are required as there is a medical need due to the lack of causal treatments. PMID:26903868

Role of the Sympathetic Nervous System and Its Modulation in Renal Hypertension.

Science.gov (United States)

Sata, Yusuke; Head, Geoffrey A; Denton, Kate; May, Clive N; Schlaich, Markus P

2018-01-01

The kidneys are densely innervated with renal efferent and afferent nerves to communicate with the central nervous system. Innervation of major structural components of the kidneys, such as blood vessels, tubules, the pelvis, and glomeruli, forms a bidirectional neural network to relay sensory and sympathetic signals to and from the brain. Renal efferent nerves regulate renal blood flow, glomerular filtration rate, tubular reabsorption of sodium and water, as well as release of renin and prostaglandins, all of which contribute to cardiovascular and renal regulation. Renal afferent nerves complete the feedback loop via central autonomic nuclei where the signals are integrated and modulate central sympathetic outflow; thus both types of nerves form integral parts of the self-regulated renorenal reflex loop. Renal sympathetic nerve activity (RSNA) is commonly increased in pathophysiological conditions such as hypertension and chronic- and end-stage renal disease. Increased RSNA raises blood pressure and can contribute to the deterioration of renal function. Attempts have been made to eliminate or interfere with this important link between the brain and the kidneys as a neuromodulatory treatment for these conditions. Catheter-based renal sympathetic denervation has been successfully applied in patients with resistant hypertension and was associated with significant falls in blood pressure and renal protection in most studies performed. The focus of this review is the neural contribution to the control of renal and cardiovascular hemodynamics and renal function in the setting of hypertension and chronic kidney disease, as well as the specific roles of renal efferent and afferent nerves in this scenario and their utility as a therapeutic target.

A new human NHERF1 mutation decreases renal phosphate transporter NPT2a expression by a PTH-independent mechanism.

Directory of Open Access Journals (Sweden)

Marie Courbebaisse

Full Text Available BACKGROUND: The sodium-hydrogen exchanger regulatory factor 1 (NHERF1 binds to the main renal phosphate transporter NPT2a and to the parathyroid hormone (PTH receptor. We have recently identified mutations in NHERF1 that decrease renal phosphate reabsorption by increasing PTH-induced cAMP production in the renal proximal tubule. METHODS: We compared relevant parameters of phosphate homeostasis in a patient with a previously undescribed mutation in NHERF1 and in control subjects. We expressed the mutant NHERF1 protein in Xenopus Oocytes and in cultured cells to study its effects on phosphate transport and PTH-induced cAMP production. RESULTS: We identified in a patient with inappropriate renal phosphate reabsorption a previously unidentified mutation (E68A located in the PDZ1 domain of NHERF1.We report the consequences of this mutation on NHERF1 function. E68A mutation did not modify cAMP production in the patient. PTH-induced cAMP synthesis and PKC activity were not altered by E68A mutation in renal cells in culture. In contrast to wild-type NHERF1, expression of the E68A mutant in Xenopus oocytes and in human cells failed to increase phosphate transport. Pull down experiments showed that E68A mutant did not interact with NPT2a, which robustly interacted with wild type NHERF1 and previously identified mutants. Biotinylation studies revealed that E68A mutant was unable to increase cell surface expression of NPT2a. CONCLUSIONS: Our results indicate that the PDZ1 domain is critical for NHERF1-NPT2a interaction in humans and for the control of NPT2a expression at the plasma membrane. Thus we have identified a new mechanism of renal phosphate loss and shown that different mutations in NHERF1 can alter renal phosphate reabsorption via distinct mechanisms.

The crosstalk between the kidney and the central nervous system: the role of renal nerves in blood pressure regulation.

Science.gov (United States)

Nishi, Erika E; Bergamaschi, Cássia T; Campos, Ruy R

2015-04-20

What is the topic of this review? This review describes the role of renal nerves as the key carrier of signals from the kidneys to the CNS and vice versa; the brain and kidneys communicate through this carrier to maintain homeostasis in the body. What advances does it highlight? Whether renal or autonomic dysfunction is the predominant contributor to systemic hypertension is still debated. In this review, we focus on the role of the renal nerves in a model of renovascular hypertension. The sympathetic nervous system influences the renal regulation of arterial pressure and body fluid composition. Anatomical and physiological evidence has shown that sympathetic nerves mediate changes in urinary sodium and water excretion by regulating the renal tubular water and sodium reabsorption throughout the nephron, changes in the renal blood flow and the glomerular filtration rate by regulating the constriction of renal vasculature, and changes in the activity of the renin-angiotensin system by regulating the renin release from juxtaglomerular cells. Additionally, renal sensory afferent fibres project to the autonomic central nuclei that regulate blood pressure. Hence, renal nerves play a key role in the crosstalk between the kidneys and the CNS to maintain homeostasis in the body. Therefore, the increased sympathetic nerve activity to the kidney and the renal afferent nerve activity to the CNS may contribute to the outcome of diseases, such as hypertension. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Evidence of active transport of cadmium complexing dithiocarbamates into renal and hepatic cells in vivo

International Nuclear Information System (INIS)

Gale, G.R.; Smith, A.B.; Jones, M.M.; Singh, P.K.

1992-01-01

A study was made of the effects of certain inhibitors of transport systems on the actions of four cadmium (Cd) complexing N,N-disubstituted dithiocarbamates (DTCs) in mobilizing murine renal and hepatic Cd in vivo. Probenecid, the prototypical antagonist of organic anion transport in the kidney, when given 1 hr prior to each DTC, sharply suppressed the DTC-induced reduction of renal Cd but was virtually without effect on mobilization of Cd from liver. Sulfinpyrazone, which blocks tubular reabsorption of uric acid and also inhibits transport of a variety of organic acids, inhibited markedly the mobilization of both renal and hepatic Cd by DTCs. Phlorizin, an inhibitor of tubular sugar reabsorption, did not affect the Cd mobilizing actions of DTCs in any consistent fashion. We propose that the high degree of selectivity of DTCs in mobilizing renal hepatic Cd is dependent, at lest in part, upon active transport of DTCs into these tissues via the organic anion transport systems. This report presents the first evidence that compounds of the (R) 2 NCSS - class may gain access to intracellular space by an active, carrier-mediated process. (au)

THE TRAFFICKING OF THE WATER CHANNEL AQUAPORIN-2 IN RENAL PRINCIPAL CELLS – A POTENTIAL TARGET FOR PHARMACOLOGICAL INTERVENTION IN CARDIOVASCULAR DISEASES

Directory of Open Access Journals (Sweden)

Tanja eVukicevic

2016-02-01

Full Text Available Arginine-vasopressin (AVP stimulates the redistribution of water channels, aquaporin-2 (AQP2 from intracellular vesicles into the plasma membrane of renal collecting duct principal cells. By this AVP directs 10 % of the water reabsorption from the 170 L of primary urine that the human kidneys produce each day. This review discusses molecular mechanisms underlying the AVP-induced redistribution of AQP2; in particular, it provides an overview over the proteins participating in the control of its localization. Defects preventing the insertion of AQP2 into the plasma membrane cause diabetes insipidus. The disease can be acquired or inherited, and is characterized by polyuria and polydipsia. Vice versa, up-regulation of the system causing a predominant localization of AQP2 in the plasma membrane leads to excessive water retention and hyponatremia as in the syndrome of inappropriate antidiuretic hormone secretion (SIADH, late stage heart failure or liver cirrhosis. This article briefly summarizes the currently available pharmacotherapies for the treatment of such water balance disorders, and discusses the value of newly identified mechanisms controlling AQP2 for developing novel pharmacological strategies. Innovative concepts for the therapy of water balance disorders are required as there is a medical need due to the lack of causal treatments.

Effects of renal denervation on tubular sodium handling in rats with CBL-induced liver cirrhosis

DEFF Research Database (Denmark)

Jonassen, T.E.; Brond, L.; Torp, M.

2003-01-01

This study was designed to examine the effect of bilateral renal denervation (DNX) on thick ascending limb of Henle's loop (TAL) function in rats with liver cirrhosis induced by common bile duct ligation (CBL). The CBL rats had, as previously shown, sodium retention associated with hypertrophy...... renal sympathetic nerve activity known to be present in CBL rats plays a significant role in the formation of sodium retention by stimulating sodium reabsorption in the TAL via increased renal abundance of NKCC2....

Role of the Sympathetic Nervous System and Its Modulation in Renal Hypertension

Directory of Open Access Journals (Sweden)

Yusuke Sata

2018-03-01

Full Text Available The kidneys are densely innervated with renal efferent and afferent nerves to communicate with the central nervous system. Innervation of major structural components of the kidneys, such as blood vessels, tubules, the pelvis, and glomeruli, forms a bidirectional neural network to relay sensory and sympathetic signals to and from the brain. Renal efferent nerves regulate renal blood flow, glomerular filtration rate, tubular reabsorption of sodium and water, as well as release of renin and prostaglandins, all of which contribute to cardiovascular and renal regulation. Renal afferent nerves complete the feedback loop via central autonomic nuclei where the signals are integrated and modulate central sympathetic outflow; thus both types of nerves form integral parts of the self-regulated renorenal reflex loop. Renal sympathetic nerve activity (RSNA is commonly increased in pathophysiological conditions such as hypertension and chronic- and end-stage renal disease. Increased RSNA raises blood pressure and can contribute to the deterioration of renal function. Attempts have been made to eliminate or interfere with this important link between the brain and the kidneys as a neuromodulatory treatment for these conditions. Catheter-based renal sympathetic denervation has been successfully applied in patients with resistant hypertension and was associated with significant falls in blood pressure and renal protection in most studies performed. The focus of this review is the neural contribution to the control of renal and cardiovascular hemodynamics and renal function in the setting of hypertension and chronic kidney disease, as well as the specific roles of renal efferent and afferent nerves in this scenario and their utility as a therapeutic target.

Effects of hyperventilation and hypocapnic/normocapnic hypoxemia on renal function and lithium clearance in humans

DEFF Research Database (Denmark)

Christensen, H; Klausen, T; Fogh-Andersen, N

1998-01-01

Using the renal clearance of lithium as an index of proximal tubular outflow, this study tested the hypothesis that acute hypocapnic hypoxemia decreases proximal tubular reabsorption to the same extent as hypocapnic normoxemia (hyperventilation) and that this response is blunted during normocapnic...

Increased salt consumption induces body water conservation and decreases fluid intake.

Science.gov (United States)

Rakova, Natalia; Kitada, Kento; Lerchl, Kathrin; Dahlmann, Anke; Birukov, Anna; Daub, Steffen; Kopp, Christoph; Pedchenko, Tetyana; Zhang, Yahua; Beck, Luis; Johannes, Bernd; Marton, Adriana; Müller, Dominik N; Rauh, Manfred; Luft, Friedrich C; Titze, Jens

2017-05-01

The idea that increasing salt intake increases drinking and urine volume is widely accepted. We tested the hypothesis that an increase in salt intake of 6 g/d would change fluid balance in men living under ultra-long-term controlled conditions. Over the course of 2 separate space flight simulation studies of 105 and 205 days' duration, we exposed 10 healthy men to 3 salt intake levels (12, 9, or 6 g/d). All other nutrients were maintained constant. We studied the effect of salt-driven changes in mineralocorticoid and glucocorticoid urinary excretion on day-to-day osmolyte and water balance. A 6-g/d increase in salt intake increased urine osmolyte excretion, but reduced free-water clearance, indicating endogenous free water accrual by urine concentration. The resulting endogenous water surplus reduced fluid intake at the 12-g/d salt intake level. Across all 3 levels of salt intake, half-weekly and weekly rhythmical mineralocorticoid release promoted free water reabsorption via the renal concentration mechanism. Mineralocorticoid-coupled increases in free water reabsorption were counterbalanced by rhythmical glucocorticoid release, with excretion of endogenous osmolyte and water surplus by relative urine dilution. A 6-g/d increase in salt intake decreased the level of rhythmical mineralocorticoid release and elevated rhythmical glucocorticoid release. The projected effect of salt-driven hormone rhythm modulation corresponded well with the measured decrease in water intake and an increase in urine volume with surplus osmolyte excretion. Humans regulate osmolyte and water balance by rhythmical mineralocorticoid and glucocorticoid release, endogenous accrual of surplus body water, and precise surplus excretion. Federal Ministry for Economics and Technology/DLR; the Interdisciplinary Centre for Clinical Research; the NIH; the American Heart Association (AHA); the Renal Research Institute; and the TOYOBO Biotechnology Foundation. Food products were donated by APETITO

Roles of estrogen and progesterone in modulating renal nerve function in the rat kidney

International Nuclear Information System (INIS)

Graceli, J.B.; Cicilini, M.A.; Bissoli, N.S.; Abreu, G.R.; Moysés, M.R.

2013-01-01

The maintenance of extracellular Na + and Cl - concentrations in mammals depends, at least in part, on renal function. It has been shown that neural and endocrine mechanisms regulate extracellular fluid volume and transport of electrolytes along nephrons. Studies of sex hormones and renal nerves suggested that sex hormones modulate renal function, although this relationship is not well understood in the kidney. To better understand the role of these hormones on the effects that renal nerves have on Na + and Cl - reabsorption, we studied the effects of renal denervation and oophorectomy in female rats. Oophorectomized (OVX) rats received 17β-estradiol benzoate (OVE, 2.0 mg·kg -1 ·day -1 , sc) and progesterone (OVP, 1.7 mg·kg -1 ·day -1 , sc). We assessed Na + and Cl - fractional excretion (FE Na + and FE Cl - , respectively) and renal and plasma catecholamine release concentrations. FE Na + , FE Cl - , water intake, urinary flow, and renal and plasma catecholamine release levels increased in OVX vs control rats. These effects were reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation did not alter FE Na + , FE Cl - , water intake, or urinary flow values vs controls. However, the renal catecholamine release level was decreased in the OVP (236.6±36.1 ng/g) and denervated rat groups (D: 102.1±15.7; ODE: 108.7±23.2; ODP: 101.1±22.1 ng/g). Furthermore, combining OVX + D (OD: 111.9±25.4) decreased renal catecholamine release levels compared to either treatment alone. OVE normalized and OVP reduced renal catecholamine release levels, and the effects on plasma catecholamine release levels were reversed by ODE and ODP replacement in OD. These data suggest that progesterone may influence catecholamine release levels by renal innervation and that there are complex interactions among renal nerves, estrogen, and progesterone in the modulation of renal function

Is nectar reabsorption restricted by the stalk cells of floral and extrafloral nectary trichomes?

Science.gov (United States)

Cardoso-Gustavson, P; Davis, A R

2015-01-01

Reabsorption is a phase of nectar dynamics that occurs concurrently with secretion; it has been described in floral nectaries that exude nectar through stomata or unicellular trichomes, but has not yet been recorded in extrafloral glands. Apparently, nectar reabsorption does not occur in multicellular secretory trichomes (MST) due to the presence of lipophilic impregnations - which resemble Casparian strips - in the anticlinal walls of the stalk cells. It has been assumed that these impregnations restrict solute movement within MST to occur unidirectionally and exclusively by the symplast, thereby preventing nectar reflux toward the underlying nectary tissues. We hypothesised that reabsorption is absent in nectaries possessing MST. The fluorochrome lucifer yellow (LYCH) was applied to standing nectar of two floral and extrafloral glands of distantly related species, and then emission spectra from nectary sections were systematically analysed using confocal microscopy. Passive uptake of LYCH via the stalk cells to the nectary tissues occurred in all MST examined. Moreover, we present evidence of nectar reabsorption in extrafloral nectaries, demonstrating that LYCH passed the stalk cells of MST, although it did not reach the deepest nectary tissues. Identical (control) experiments performed with neutral red (NR) demonstrated no uptake of this stain by actively secreting MST, whereas diffusion of NR did occur in plasmolysed MST of floral nectaries at the post-secretory phase, indicating that nectar reabsorption by MST is governed by stalk cell physiology. Interestingly, non-secretory trichomes failed to reabsorb nectar. The role of various nectary components is discussed in relation to the control of nectar reabsorption by secretory trichomes. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Inhibition of renal glucose reabsorption as a novel treatment for diabetes patients

Directory of Open Access Journals (Sweden)

Eugenio Cersosimo

2014-03-01

Full Text Available The importance of the kidney in glucose homeostasis has been recognized for many years. Recent observations indicating a greater role of renal glucose metabolism in various physiologic and pathologic conditions have rekindled the interest in renal glucose handling as a potential target for the treatment of diabetes. The enormous capacity of the proximal tubular cells to reabsorb the filtered glucose load entirely, utilizing the sodium-glucose co-transporter system (primarily SGLT-2, became the focus of attention. Original studies conducted in experimental animals with the nonspecific SGLT inhibitor phlorizin showed that hyperglycemia after pancreatectomy decreased as a result of forced glycosuria. Subsequently, several compounds with more selective SGLT-2 inhibition properties (“second-generation” were developed. Some agents made it into pre-clinical and clinical trials and a few have already been approved for commercial use in the treatment of type 2 diabetes. In general, a 6-month period of therapy with SGLT-2 inhibitors is followed by a mean urinary glucose excretion rate of ~80 g/day accompanied by a decline in fasting and postprandial glucose with average decreases in HgA1C ~1.0%. Concomitant body weight loss and a mild but consistent drop in blood pressure also have been reported. In contrast, transient polyuria, thirst with dehydration and occasional hypotension have been described early in the treatment. In addition, a significant increase in the occurrence of uro-genital infections, particularly in women has been documented with the use of SGLT-2 inhibitors. Conclusion: Although long-term cardiovascular, renal and bone/mineral effects are unknown SGLT-2 inhibitors, if used with caution and in the proper patient provide a unique insulin-independent therapeutic option in the management of obese type 2 diabetes patients.

Water transport by the renal Na(+)-dicarboxylate cotransporter

DEFF Research Database (Denmark)

Meinild, A K; Loo, D D; Pajor, A M

2000-01-01

. This solute-coupled influx of water took place in the absence of, and even against, osmotic gradients. There was a strict stoichiometric relationship between Na(+), substrate, and water transport of 3 Na(+), 1 dicarboxylate, and 176 water molecules/transport cycle. These results indicate that the renal Na......This study investigated the ability of the renal Na(+)-dicarboxylate cotransporter, NaDC-1, to transport water. Rabbit NaDC-1 was expressed in Xenopus laevis oocytes, cotransporter activity was measured as the inward current generated by substrate (citrate or succinate), and water transport...... was monitored by the changes in oocyte volume. In the absence of substrates, oocytes expressing NaDC-1 showed an increase in osmotic water permeability, which was directly correlated with the expression level of NaDC-1. When NaDC-1 was transporting substrates, there was a concomitant increase in oocyte volume...

Nectar reabsorption and sugar translocation in male and female flowers of Cucurbita pepo

International Nuclear Information System (INIS)

Stpiczynska, M.; Nepi, M.

2005-01-01

Full text: The production and secretion of nectar has an energy cost that can be a substantial part of the energy economy of the plant. Plants may therefore recover part of the energy allocated to nectar secretion by reabsorbing nectar not collected by pollinators. This energy-saving strategy has been demonstrated by several authors by different methods. Here we demonstrate nectar reabsorption and sugar translocation in Cucurbita pepo by means of microautoradiography. Our results confirm that the dynamics of nectar reabsorption is different in male and female flowers. Differences in the dynamics of nectar reabsorption and sugar translocation were also found in pollinated and unpollinated female flowers. Pollinated female flowers reabsorbed sugar very quickly and translocated it to developing fruits in which ovules were the main sugar sink. Sugar translocation was slower and ovules did not label in unpollinated female flowers. (author)

A novel description of FDG excretion in the renal system: application to metformin-treated models

Science.gov (United States)

Garbarino, S.; Caviglia, G.; Sambuceti, G.; Benvenuto, F.; Piana, M.

2014-05-01

This paper introduces a novel compartmental model describing the excretion of 18F-fluoro-deoxyglucose (FDG) in the renal system and a numerical method based on the maximum likelihood for its reduction. This approach accounts for variations in FDG concentration due to water re-absorption in renal tubules and the increase of the bladder’s volume during the FDG excretion process. From the computational viewpoint, the reconstruction of the tracer kinetic parameters is obtained by solving the maximum likelihood problem iteratively, using a non-stationary, steepest descent approach that explicitly accounts for the Poisson nature of nuclear medicine data. The reliability of the method is validated against two sets of synthetic data realized according to realistic conditions. Finally we applied this model to describe FDG excretion in the case of animal models treated with metformin. In particular we show that our approach allows the quantitative estimation of the reduction of FDG de-phosphorylation induced by metformin.

A novel description of FDG excretion in the renal system: application to metformin-treated models

International Nuclear Information System (INIS)

Garbarino, S; Caviglia, G; Piana, M; Sambuceti, G; Benvenuto, F

2014-01-01

This paper introduces a novel compartmental model describing the excretion of 18F-fluoro-deoxyglucose (FDG) in the renal system and a numerical method based on the maximum likelihood for its reduction. This approach accounts for variations in FDG concentration due to water re-absorption in renal tubules and the increase of the bladder’s volume during the FDG excretion process. From the computational viewpoint, the reconstruction of the tracer kinetic parameters is obtained by solving the maximum likelihood problem iteratively, using a non-stationary, steepest descent approach that explicitly accounts for the Poisson nature of nuclear medicine data. The reliability of the method is validated against two sets of synthetic data realized according to realistic conditions. Finally we applied this model to describe FDG excretion in the case of animal models treated with metformin. In particular we show that our approach allows the quantitative estimation of the reduction of FDG de-phosphorylation induced by metformin. (paper)

Hemodynamic and renal implications of sodium-glucose cotransporter- 2 inhibitors in type 2 diabetes mellitus.

Science.gov (United States)

Tejedor Jorge, Alberto

2016-11-01

In DM2, there is increased expression of the proximal glucose transporter SGLT2. The increased glucose reabsorption from the urine to the proximal tubule and subsequently to the bloodstream, has three direct effects on the prognosis of patients with DM2: a) it increases the daily glucose load by raising the renal threshold for glucose, thus augmenting requirements for oral antidiabetics and insulin. This progressive increase occurs throughout the course of the disease and in parallel with the increase in renal mass (renal hypertrophy); b) because of the greater glucose reabsorption, glycosuria is lower than the level corresponding to glycaemia, decreasing the stimulus on the tubuloglomerular feedback system of the distal nephron. As a result, the glomerular vasodilation caused by hyperglycaemia is not arrested, maintaining glomerular hyperfiltration, and c) the excess glucose transported to the proximal tubular cells modifies their redox status, increasing local production of glycosylating products and activating local production of proinflammatory and profibrotic proliferative mediators. These mediators are responsible for the direct free radical damage to proximal tubular cells, for increased SGLT2 expression, increased production of collagen IV and extracellular matrix, and activation of monocyte/macrophages able to cause endothelial injury. The use of SGLT2 inhibitors not only reduces the reabsorption of glucose from the glomerular filtrate back into the circulationthus improving metabolic control in diabetesbut also restores tubuloglomerular feedback by increasing glycosuria and distal urinary flow. However, the most notable effect is due to inhibition of glucose entry to the proximal tubular cells. Glycosuria is toxic to the kidney: it harms glucosetransporting cells, that is, the proximal cells, which contain SGLT2. In animal models, SGLT2 inhibition reduces local production of oxygen-free radicals, the formation of mesangial matrix and collagen IV

Is the renal kallikrein-kinin system a factor that modulates hypercalciuria?

Directory of Open Access Journals (Sweden)

Armando Luis Negri

2017-01-01

Full Text Available Renal tubular calcium reabsorption is one of the principal factors that determine serum calcium concentration and calcium excretion. Calcium excretion is regulated by the distal convoluted tubule and connecting tubule, where the epithelial calcium channel TRPV5 can be found, which limits the rate of transcellular calcium transport. The dynamic presence of the TRPV5 channel on the surface of the tubular cell is mediated by an endosomal recycling process. Different intrarenal factors are involved in calcium channel fixation in the apical membrane, including the anti-ageing hormone klotho and tissue kallikrein (TK. Both proteins are synthesised in the distal tubule and secreted in the tubular fluid. TK stimulates active calcium reabsorption through the bradykinin receptor B2 that compromises TRPV5 activation through the protein kinase C pathway. TK-deficient mice show hypercalciuria of renal origin comparable to that seen in TRPV5 knockout mice. There is a polymorphism with loss of function of the human TK gene R53H (allele H that causes a marked decrease in enzymatic activity. The presence of the allele H seems to be common at least in the Japanese population (24%. These individuals have a tendency to greater calcium and sodium excretion in urine that is more evident during furosemide infusion. Future studies should analyse if manipulating the renal kallikrein-kinin system can correct idiopathic hypercalciuria with drugs other than thiazide diuretics.

Whites excrete a water load more rapidly than blacks.

Science.gov (United States)

Weder, Alan B; Gleiberman, Lillian; Sachdeva, Amit

2009-04-01

A recent report demonstrated a racial difference in response to furosemide compatible with increased ion reabsorption in the thick ascending limb of the loop of Henle in blacks. Urinary dilution is another function of the loop-diuretic-sensitive Na,K,2Cl cotransporter in the thick ascending limb, and racial differences in urinary diluting capacity have not been reported previously. We assessed diluting segment (cortical thick ascending limb and distal convoluted tubule) function in black and white normotensives in 2 studies using a water-loading approach. In both studies, we found that whites excreted a water load more rapidly than blacks. In the first study, the final free water clearance rates (mean+/-SD) were 7.3+/-4.7 mL/min in whites (n=17, 7 females and 10 males) and 3.8+/-3.6 mL/min in blacks (n=14, 9 females and 5 males; Pwater clearance rates were 8.3+/-2.6 mL/min in whites (n=17, 8 females and 9 males) and 6.4+/-1.8 mL/min in blacks (n=11, 8 females and 3 males; Pwater excretion. We conclude that our observations are most consistent with a lower capacity of ion reabsorption in the renal diluting segment in blacks. Slower excretion of an acute water load may have been an advantage during natural selection of humans living in arid, hot climates.

Factors Influencing the Increase in Na-K-ATPase in Compensatory Renal Hypertrophy

Science.gov (United States)

Epstein, Franklin H.; Charney, Alan N.; Silva, Patricio

1978-01-01

An increase in Na-K-ATPase in kidney homogenates usually accompanies compensatory renal hypertrophy. While it may be evident in both the cortex and medulla of the kidney, it is most marked in the outer medulla and may be present only in that region. The increase in enzyme activity does not depend on an intact adrenal cortex and can be elicited in the absence of adrenal glucocorticoids. It is not seen in the form of renal hypertrophy produced by potassium depletion, in which the transport of sodium and potassium by the kidney is not increased. When present in compensatory renal growth, the enzyme change is correlated with an increase in the reabsorption of sodium, or the excretion of potassium, or both, per unit of renal tissue. It proceeds in the presence of either, but not in the absence of both. PMID:216164

Effect of metabolic acidosis on renal tubular sodium handling in rats as determined by lithium clearance

Directory of Open Access Journals (Sweden)

Menegon L.F.

1998-01-01

Full Text Available Systemic metabolic acidosis is known to cause a decrease in salt and water reabsorption by the kidney. We have used renal lithium clearance to investigate the effect of chronic, NH4Cl-induced metabolic acidosis on the renal handling of Na+ in male Wistar-Hannover rats (200-250 g. Chronic acidosis (pH 7.16 ± 0.13 caused a sustained increase in renal fractional Na+ excretion (267.9 ± 36.4%, accompanied by an increase in fractional proximal (113.3 ± 3.6% and post-proximal (179.7 ± 20.2% Na+ and urinary K+ (163.4 ± 5.6% excretion when compared to control and pair-fed rats. These differences occurred in spite of an unchanged creatinine clearance and Na+ filtered load. A lower final body weight was observed in the acidotic (232 ± 4.6 g and pair-fed (225 ± 3.6 g rats compared to the controls (258 ± 3.7 g. In contrast, there was a significant increase in the kidney weights of acidotic rats (1.73 ± 0.05 g compared to the other experimental groups (control, 1.46 ± 0.05 g; pair-fed, 1.4 ± 0.05 g. We suggest that altered renal Na+ and K+ handling in acidotic rats may result from a reciprocal relationship between the level of metabolism in renal tubules and ion transport.

Patterned dye structures limit reabsorption in luminescent solar concentrators

NARCIS (Netherlands)

Tsoi, S.; Broer, D.J.; Bastiaansen, C.W.M.; Debije, M.G.

2010-01-01

This work describes a method for limiting internal losses of a luminescent solar concentrator (LSC) due to reabsorption through patterning the fluorescent dye doped coating of the LSC. By engineering the dye coating into regular line patterns with fill factors ranging from 20 - 80%, the surface

Non-postural serial changes in renal function during the third trimester of normal human pregnancy.

Science.gov (United States)

Ezimokhai, M; Davison, J M; Philips, P R; Dunlop, W

1981-05-01

Seventeen healthy women were investigated near the beginning and again near the end of the third trimester of their normal pregnancies. Infusion studies were performed in the left lateral position. There was a highly significant decrease in effective renal plasma flow but not in glomerular filtration rate, measured as inulin clearance. Plasma creatinine concentration increased significantly, but the renal handling of creatinine was unchanged; simultaneous 24-hour creatinine clearance showed a tendency to decrease. Serum urate concentration also increased significantly, apparently due to an increase in net tubular reabsorption of urate.

Reversed polarized delivery of an aquaporin-2 mutant causes dominant nephrogenic diabetes insipidus.

NARCIS (Netherlands)

Kamsteeg, E.J.; Bichet, D.G.; Konings, I.B.M.; Nivet, H.; Lonergan, M.; Arthus, M.F.; Os, C.H. van; Deen, P.M.T.

2003-01-01

Vasopressin regulates body water conservation by redistributing aquaporin-2 (AQP2) water channels from intracellular vesicles to the apical surface of renal collecting ducts, resulting in water reabsorption from urine. Mutations in AQP2 cause autosomal nephrogenic diabetes insipidus (NDI), a disease

Ion transporters for fluid reabsorption in the rooster (Gallus domesticus) epididymal region.

Science.gov (United States)

Bahr, J M; Dalponte, M; Janssen, S; Bunick, D; Nakai, M

2006-10-01

Testicular fluid is highly condensed during its passage through the epididymal region in the avian species. In the present study, major ion transporters that are responsible for condensation mainly by water resorption in the reproductive tract as identified in the mammalian epididymis were localized within the rooster (Gallus domesticus) epididymis by immunohistochemistry. The results show that the efferent ductule epithelium expressed sodium-potassium ATPase (Na(+),K(+)-ATPase), carbonic anhydrase II (CAII) and sodium hydrogen exchanger isoform 3 (NHE3) and that the connecting ductule and epididymal duct epithelia expressed Na(+),K(+)-ATPase and CAII. These data suggest that a model proposed for reabsorption in mammalian efferent ductules can be applied to avian efferent ductules.

Accurate determination of renal function in patients with intestinal urinary diversions

International Nuclear Information System (INIS)

McDougal, W.S.; Koch, M.O.

1986-01-01

The regular determination of renal function is a critical part of the management of patients who have had the urinary tract reconstructed with intestinal segments. These intestinal segments reabsorb urinary solutes and, thereby, complicate the determination of renal function by conventional methods. Urinary clearances of urea, creatinine and inulin were performed in patients with intestinal segments in the urinary tract and controls under varying diuretic conditions. Patients with intestinal diversions also underwent radioisotopic determination of renal function. The urinary clearances of urea, creatinine and inulin are highly dependent on the rate of urine flow in patients with intestinal segments in the urinary tract. Diuresis maximizes the urinary clearances of these solutes by minimizing intestinal reabsorption. Creatinine clearance prediction from the serum creatinine underestimates true glomerular filtration rate. Radioisotopic determination of renal function correlates poorly with true glomerular filtration rate. Only creatinine clearance measured under diuretic conditions correlates well with true renal function. Urine concentrating ability cannot be assessed accurately in patients with intestinal segments in the urinary tract, since osmolality rapidly equilibrates across the segments

Mineralocorticoid-induced sodium appetite and renal salt retention: Evidence for common signaling and effector mechanisms

Science.gov (United States)

Fu, Yiling; Vallon, Volker

2014-01-01

An increase in renal sodium chloride (salt) retention and an increase in sodium appetite is the body's response to salt restriction or depletion in order to restore salt balance. Renal salt retention and increased sodium appetite can also be maladaptive and sustain the pathophysiology in conditions like salt-sensitive hypertension and chronic heart failure. Here we review the central role of the mineralocorticoid aldosterone in both the increase in renal salt reabsorption and sodium appetite. We discuss the working hypothesis that aldosterone activates similar signaling and effector mechanisms in the kidney and brain, including the mineralocorticoid receptor, the serum-and-glucocorticoid-induced kinase SGK1, the ubiquitin ligase NEDD4-2, and the epithelial sodium channel ENaC. The latter also mediates the gustatory salt sensing in the tongue, which is required for the manifestation of increased salt intake. Effects of aldosterone on both brain and kidney synergize with the effects of angiotensin II. Thus, mineralocorticoids appear to induce similar molecular pathways in the kidney, brain, and possibly tongue, which could provide opportunities for more effective therapeutic interventions. Inhibition of renal salt reabsorption is compensated by stimulation of salt appetite and vice versa; targeting both mechanisms should be more effective. Inhibiting the arousal to consume salty food may improve a patient's compliance to reducing salt intake. While a better understanding of the molecular mechanisms is needed and will provide new options, current pharmacological interventions that target both salt retention and sodium appetite include mineralocorticoid receptor antagonists and potentially inhibitors of angiotensin II and ENaC. PMID:25376899

Lithium clearance in chronic nephropathy

DEFF Research Database (Denmark)

Kamper, A L; Holstein-Rathlou, N H; Leyssac, P P

1989-01-01

1. Lithium clearance measurements were made in 72 patients with chronic nephropathy of different aetiology and moderate to severely reduced renal function. 2. Lithium clearance was strictly correlated with glomerular filtration rate, and there was no suggestion of distal tubular reabsorption...... of lithium or influence of osmotic diuresis. 3. Fractional reabsorption of lithium was reduced in most patients with glomerular filtration rates below 25 ml/min. 4. Calculated fractional distal reabsorption of sodium was reduced in most patients with glomerular filtration rates below 50 ml/min. 5. Lithium...... that lithium clearance may be a measure of the delivery of sodium and water from the renal proximal tubule. With this assumption it was found that adjustment of the sodium excretion in chronic nephropathy initially takes place in the distal parts of the nephron (loop of Henle, distal tubule and collecting duct...

Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

International Nuclear Information System (INIS)

Pedersen, Michael; Aarhus Univ.; Univ. Victor Segalen Bordeaux 2; Laustsen, Christoffer; Perot, Vincent; Grenier, Nicolas; Basseau, Fabrice; Moonen, Chrit

2010-01-01

Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2 * , and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2 * was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

Renal hemodynamics and oxygenation in transient renal artery occluded rats evaluated with iron-oxide particles and oxygenation-sensitive imaging

Energy Technology Data Exchange (ETDEWEB)

Pedersen, Michael [Aarhus Univ. Hospital (Denmark). MR Research Centre; Aarhus Univ. (Denmark). Inst. of Experimental Clinical Medicine; Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231; Laustsen, Christoffer [Aarhus Univ. Hospital (Denmark). MR Research Centre; Perot, Vincent; Grenier, Nicolas [Hopital Pellegrin, CHU Bordeaux (France). Service d' Imagerie Diagnostique et Therapeutique de l' Adulte; Basseau, Fabrice; Moonen, Chrit [Univ. Victor Segalen Bordeaux 2 (France). Lab. Imagerie Moleculaire et Fonctionnelle: de la physiologie a la therapie CNRS UMR 5231

2010-07-01

Mild or severe renal arterial occlusion is a phenomenon occasionally observed in daily clinical practice, potentially leading to renal ischemia and a general impairment of renal function. Secondly, closing the blood flow to the kidneys can also occur during kidney transplantation procedures. However, the exact physiological effects of these conditions on renal blood perfusion as well as the renal oxygen handling are poorly understood. The objectives of this study were therefore to measure the lateral changes of renal blood perfusion in rats subjected to transient unilateral arterial occlusion (RAS), and in addition, to measure the consequences on the intrarenal oxygenation. Experimental studies were performed using sixteen adolescent rats. The left renal artery was exposed through a flank incision and acute RAS for 45 min was achieved by placing a ligature around the renal artery. MRI was performed 3 days after the surgical procedure, where a blood oxygenation sensitive sequence (BOLD MRI) was performed, followed by a perfusion-weighted imaging sequence using a single bolus of the iron-oxide nanoparticle Sinerem. The renal oxygenation of blood was indirectly measured by the BOLD-parameter R2{sup *}, and perfusion measures include relative renal blood flow, relative renal blood volume and mean transit time. Histopathologic changes through the outer stripe of the outer medulla showing typical histopathologic findings of ischemia. This study demonstrated that rats with transient renal arterial stenosis (for 45 min) showed a reduction in intrarenal oxygenation and intrarenal blood flow three days after the surgical procedure. A decreased R2{sup *} was measured within the ipsilateral medulla in parallel with a decreased medullary blood flow, is probably related to a lower reabsorption load within the ipsilateral kidney. MRI may therefore be a promising tool in long-term evaluation of RAS. (orig.)

Renal glucose metabolism in normal physiological conditions and in diabetes.

Science.gov (United States)

Alsahli, Mazen; Gerich, John E

2017-11-01

The kidney plays an important role in glucose homeostasis via gluconeogenesis, glucose utilization, and glucose reabsorption from the renal glomerular filtrate. After an overnight fast, 20-25% of glucose released into the circulation originates from the kidneys through gluconeogenesis. In this post-absorptive state, the kidneys utilize about 10% of all glucose utilized by the body. After glucose ingestion, renal gluconeogenesis increases and accounts for approximately 60% of endogenous glucose release in the postprandial period. Each day, the kidneys filter approximately 180g of glucose and virtually all of this is reabsorbed into the circulation. Hormones (most importantly insulin and catecholamines), substrates, enzymes, and glucose transporters are some of the various factors influencing the kidney's role. Patients with type 2 diabetes have an increased renal glucose uptake and release in the fasting and the post-prandial states. Additionally, glucosuria in these patients does not occur at plasma glucose levels that would normally produce glucosuria in healthy individuals. The major abnormality of renal glucose metabolism in type 1 diabetes appears to be impaired renal glucose release during hypoglycemia. Copyright © 2017 Elsevier B.V. All rights reserved.

Diminished renal urea excretion in the llama at reduced food intake

International Nuclear Information System (INIS)

Engelhardt, W.; Engelhardt, W. von

1976-01-01

Renal urea excretion was studied in three llamas under various feeding conditions. Glomerular filtration rate (GFR) was estimated from inulin clearance. Tubular reabsorbed urea was the difference between glomerular filtered and renal excreted urea. Plasma urea concentration increased significantly when feeding was reduced by 40% and 60%, not applicable to a straw diet. With reduced hay feeding and on a straw diet only a slight and insignificant decrease was observed in renal urea excretion, with only a 3% lowering in GFR and glomerular filtered urea. With a straw diet, the glomerular filtered urea was significantly below the controls. The fraction of filtered urea reabsorbed in the tubules was constant (36%-47%). Very high reabsorption (87%) on a supplemented straw dietwas observed in one llama which after nearly 6 months on this low protein diet - could be shown to have lost only 5% of its body weight

Reabsorption kinetics of albumin from pleural space of dogs

International Nuclear Information System (INIS)

Miniati, M.; Parker, J.C.; Pistolesi, M.; Cartledge, J.T.; Martin, D.J.; Giuntini, C.; Taylor, A.E.

1988-01-01

The reabsorption of albumin from the pleural space was measured in eight dogs receiving 0.5 ml intrapleural injection of 131 I-labeled albumin and a simultaneous intravenous injection of 125 I-labeled albumin. Plasma curves for both tracers were obtained over 24 h. The 125 I-albumin curve served as input function of albumin for interstitial spaces, including pleura, whereas the 131 I-albumin curve represented the output function from pleural space. The frequency function of albumin transit times from pleural space to plasma was obtained by deconvolution of input-output plasma curves. Plasma recovery of 131 I-albumin was complete by 24 h, and the mean transit time from pleura to plasma averaged 7.95 +/- 1.57 (SD) h. Albumin reabsorption occurred mainly via lymphatics as indicated by experiments in 16 additional dogs in which their right lymph ducts or thoracic ducts were ligated before intrapleural injection. A pleural lymph flow of 0.020 +/- 0.003 (SD) ml.kg-1.h-1 was estimated, which is balanced by a comparable filtration of fluid into the pleural space. This suggests that, under physiological conditions, the subpleural lymphatics represent an important control mechanism of pleural liquid pressure

Effect of tolvaptan on renal water and sodium excretion and blood pressure during nitric oxide inhibition

DEFF Research Database (Denmark)

Therwani, Safa Al; Rosenbæk, Jeppe Bakkestrøm; Mose, Frank Holden

2017-01-01

BACKGROUND: Tolvaptan is a selective vasopressin receptor antagonist. Nitric Oxide (NO) promotes renal water and sodium excretion, but the effect is unknown in the nephron's principal cells. In a dose-response study, we measured the effect of tolvaptan on renal handling of water and sodium....... CONCLUSIONS: During baseline, fractional excretion of sodium was unchanged. During tolvaptan with NO-inhibition, renal water excretion was reduced dose dependently, and renal sodium excretion was reduced unrelated to the dose, partly via an AVP dependent mechanism. Thus, tolvaptan antagonized the reduction...... in renal water and sodium excretion during NO-inhibition. Most likely, the lack of decrease in AQP2 excretion by tolvaptan could be attributed to a counteracting effect of the high level of p-AVP....

The plasma carnitine concentration regulates renal OCTN2 expression and carnitine transport in rats

OpenAIRE

Schürch, R; Todesco, L; Novakova, K; Mevissen, M; Stieger, B; Krähenbühl, S

2010-01-01

Previous findings in rats and in human vegetarians suggest that the plasma carnitine concentration and/or carnitine ingestion may influence the renal reabsorption of carnitine. We tested this hypothesis in rats with secondary carnitine deficiency following treatment with N-trimethyl-hydrazine-3-propionate (THP) for 2 weeks and rats treated with excess L-carnitine for 2 weeks. Compared to untreated control rats, treatment with THP was associated with an approximately 70% decrease in plasma car...

The influence of angiotensin-converting enzyme inhibition on renal tubular function in progressive chronic nephropathy

DEFF Research Database (Denmark)

Kamper, A L; Holstein-Rathlou, N H; Leyssac, P P

1996-01-01

The influence of angiotensin-converting enzyme (ACE) inhibition on renal tubular function in progressive chronic nephropathy was investigated in 69 patients by the lithium clearance (C(Li)) method. Studies were done repeatedly for up to 2 years during a controlled trial on the effect of enalapril...... on progression of renal failure. The pattern of proteinuria was followed over the first 9 months. At baseline, the glomerular filtration rate (GFR) was 5 to 68 mL/min. Absolute proximal tubular reabsorption rate of fluid (APR), estimated as the difference between GFR and C(Li), was 1 to 54 mL/min. Calculated...... in either treatment regimen was associated with a long-term slower progression of renal failure. Over 9 months, the 24-hour fractional clearance of albumin decreased in the ACE inhibitor group (P

The Association of Albuminuria With Tubular Reabsorption of Uric Acid: Results From a General Population Cohort

Science.gov (United States)

Scheven, Lieneke; Joosten, Michel M.; de Jong, Paul E.; Bakker, Stephan J. L.; Gansevoort, Ron T.

2014-01-01

Background Elevated albuminuria as well as an increased serum uric acid concentration is associated with poor cardiovascular outcome. We questioned whether these 2 variables (albuminuria and serum uric concentration) may be interrelated via tubular uric acid reabsorption. Methods and Results Included were 7688 participants of the PREVEND Study, an observational, general population‐based cohort study. Linear regression analyses were used to test associations of baseline albuminuria with baseline serum uric acid concentration and tubular uric acid reabsorption (calculated as [100−fractional uric acid excretion]%). Cox regression analyses were used to study the association of baseline serum uric acid and albuminuria with incident cardiovascular morbidity and mortality. In cross‐sectional analyses, albuminuria was associated positively with serum uric acid concentration, both crude and after adjustment for potential confounders (both Puric acid reabsorption, again both crude and after adjustment for potential confounders (both Puric acid were associated with incident cardiovascular events (Hazard Ratios 1.09 [1.03 to 1.17], P=0.01 and 1.19 [1.09 to 1.30], Puric acid being less predictive for cardiovascular morbidity and mortality in the presence of high albuminuria and vice versa. Conclusions Albuminuria is strongly associated with tubular uric acid reabsorption, and consequently with serum uric acid concentration. This phenomenon may explain in part why albuminuria is associated with cardiovascular outcome. PMID:24772520

Renal excretion of water-soluble contrast media after enema in the neonatal period.

Science.gov (United States)

Kim, Hee Sun; Je, Bo-Kyung; Cha, Sang Hoon; Choi, Byung Min; Lee, Ki Yeol; Lee, Seung Hwa

2014-08-01

When abdominal distention occurs or bowel obstruction is suspected in the neonatal period, a water-soluble contrast enema is helpful for diagnostic and therapeutic purposes. The water-soluble contrast medium is evacuated through the anus as well as excreted via the kidneys in some babies. This study was designed to evaluate the incidence of renal excretion after enemas using water-soluble contrast media and presume the causes. Contrast enemas using diluted water-soluble contrast media were performed in 23 patients under 2 months of age. After the enema, patients were followed with simple abdominal radiographs to assess the improvement in bowel distention, and we could also detect the presence of renal excretion of contrast media on the radiographs. Reviewing the medical records and imaging studies, including enemas and consecutive abdominal radiographs, we evaluated the incidence of renal excretion of water-soluble contrast media and counted the stay duration of contrast media in urinary tract, bladder, and colon. Among 23 patients, 12 patients (52%) experienced the renal excretion of water-soluble contrast media. In these patients, stay-in-bladder durations of contrast media were 1-3 days and stay-in-colon durations of contrast media were 1-10 days, while stay-in-colon durations of contrast media were 1-3 days in the patients not showing renal excretion of contrast media. The Mann-Whitney test for stay-in-colon durations demonstrated the later evacuation of contrast media in the patients with renal excretion of contrast media (p = 0.07). The review of the medical records showed that 19 patients were finally diagnosed as intestinal diseases, including Hirschsprung's disease, meconium ileum, meconium plug syndrome, and small bowel atresia or stenosis. Fisher's exact test between the presence of urinary excretion and intestinal diseases indicated a statistically significant difference (p = 0.04). The intestinal diseases causing bowel obstruction may increase the

Renal Proteome in Mice with Different Susceptibilities to Fluorosis

Science.gov (United States)

Peres-Buzalaf, Camila; Salvato, Fernanda; Labate, Carlos Alberto; Everett, Eric T.; Whitford, Gary Milton; Buzalaf, Marília Afonso Rabelo

2013-01-01

A/J and 129P3/J mouse strains have different susceptibilities to dental fluorosis due to their genetic backgrounds. They also differ with respect to several features of fluoride (F) metabolism and metabolic handling of water. This study was done to determine whether differences in F metabolism could be explained by diversities in the profile of protein expression in kidneys. Weanling, male A/J mice (susceptible to dental fluorosis, n = 18) and 129P3/J mice (resistant, n = 18) were housed in pairs and assigned to three groups given low-F food and drinking water containing 0, 10 or 50 ppm [F] for 7 weeks. Renal proteome profiles were examined using 2D-PAGE and LC-MS/MS. Quantitative intensity analysis detected between A/J and 129P3/J strains 122, 126 and 134 spots differentially expressed in the groups receiving 0, 10 and 50 ppmF, respectively. From these, 25, 30 and 32, respectively, were successfully identified. Most of the proteins were related to metabolic and cellular processes, followed by response to stimuli, development and regulation of cellular processes. In F-treated groups, PDZK-1, a protein involved in the regulation of renal tubular reabsorption capacity was down-modulated in the kidney of 129P3/J mice. A/J and 129P3/J mice exhibited 11 and 3 exclusive proteins, respectively, regardless of F exposure. In conclusion, proteomic analysis was able to identify proteins potentially involved in metabolic handling of F and water that are differentially expressed or even not expressed in the strains evaluated. This can contribute to understanding the molecular mechanisms underlying genetic susceptibility to dental fluorosis, by indicating key-proteins that should be better addressed in future studies. PMID:23308176

SGLT2 Inhibitors: Glucotoxicity and Tumorigenesis Downstream the Renal Proximal Tubule?

Science.gov (United States)

Bertinat, Romina; Nualart, Francisco; Yáñez, Alejandro J

2016-08-01

At present, diabetes mellitus is the main cause of end-stage renal disease. Effective glycaemic management is the most powerful tool to delay the establishment of diabetic complications, such as diabetic kidney disease. Together with reducing blood glucose levels, new anti-diabetic agents are expected not only to control the progression but also to restore known defects of the diabetic kidney. Sodium-glucose co-transporter 2 (SGLT2) inhibitors are promising anti-diabetic agents that reduce hyperglycaemia by impairing glucose reabsorption in proximal tubule of the kidney and increasing glucosuria. SGLT2 inhibitors have shown to reduce glucotoxicity in isolated proximal tubule cells and also to attenuate expression of markers of overall kidney damage in experimental animal models of diabetes, but the actual renoprotective effect for downstream nephron segments is still unknown and deserves further attention. Here, we briefly discuss possible undesired effects of enhanced glucosuria and albuminuria in nephron segments beyond the proximal tubule after SGLT2 inhibitor treatment, offering new lines of research to further understand the renoprotective action of these anti-diabetic agents. Strategies blocking glucose reabsorption by renal proximal tubule epithelial cells (RPTEC) may be protective for RPTEC, but downstream nephron segments will still be exposed to high glucose and albumin levels through the luminal face. The actual effect of constant enhanced glucosuria over distal nephron segments remains to be established. J. Cell. Physiol. 231: 1635-1637, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Hepatic, renal, and total body galactose elimination in the pig

DEFF Research Database (Denmark)

Winkler, K; Henriksen, Jens Henrik Sahl; Tygstrup, N

1993-01-01

Galactose elimination capacity is used as a quantitative measure of liver function on the assumption that galactose elimination outside the liver is negligible or easily corrected for. The relationship between hepatic and extrahepatic removal of galactose was studied in anesthetized pigs during...... reabsorption (Tm 178 +/- 3.0 mumol/min, Km 3.8 +/- 0.9 mmol/l, n = 20). Metabolic conversion of galactose in the kidney was not demonstrable. At all concentrations studied (0.4-5.8 mmol/l), total galactose elimination from the body exceeded the sum of hepatic and renal elimination by approximately 100 mumol....../min, independent of the concentration. At blood concentrations usually used for clinical estimation of the galactose elimination capacity (approximately 4 mmol/l), hepatic removal in the pig accounted for 55% and renal removal for 30% of total removal; 15% of removal occurred in other organs. We conclude...

Renal response to L-arginine in diabetic rats. A possible link between nitric oxide system and aquaporin-2.

Directory of Open Access Journals (Sweden)

María C Ortiz

Full Text Available The aim of this study was to evaluate whether L-Arginine (L-Arg supplementation modifies nitric oxide (NO system and consequently aquaporin-2 (AQP2 expression in the renal outer medulla of streptozotocin-diabetic rats at an early time point after induction of diabetes. Male Wistar rats were divided in four groups: Control, Diabetic, Diabetic treated with L-Arginine and Control treated with L-Arginine. Nitric oxide synthase (NOS activity was estimated by [14C] L-citrulline production in homogenates of the renal outer medulla and by NADPH-diaphorase staining in renal outer medullary tubules. Western blot was used to detect the expression of AQP2 and NOS types I and III; real time PCR was used to quantify AQP2 mRNA. The expression of both NOS isoforms, NOS I and NOS III, was decreased in the renal outer medulla of diabetic rats and L-Arg failed to prevent these decreases. However, L-Arg improved NO production, NADPH-diaphorase activity in collecting ducts and other tubular structures, and NOS activity in renal homogenates from diabetic rats. AQP2 protein and mRNA were decreased in the renal outer medulla of diabetic rats and L-Arg administration prevented these decreases. These results suggest that the decreased NOS activity in collecting ducts of the renal outer medulla may cause, at least in part, the decreased expression of AQP2 in this model of diabetes and constitute additional evidence supporting a role for NO in contributing to renal water reabsorption through the modulation of AQP2 expression in this pathological condition. However, we cannot discard that another pathway different from NOS also exists that links L-Arg to AQP2 expression.

Tick-Tock Chimes the Kidney Clock – from Biology of Renal Ageing to Clinical Applications

Directory of Open Access Journals (Sweden)

Joshua Rowland

2018-01-01

Full Text Available Ageing of the kidney is a multi-dimensional process that occurs simultaneously at the molecular, cellular, histological, anatomical and physiological level. Nephron number and renal cortical volume decline, renal tubules become atrophic and glomeruli become sclerotic with age. These structural changes are accompanied by a decline in glomerular filtration rate, decreased sodium reabsorption and potassium excretion, reduced urinary concentrating capacity and alterations in the endocrine activity of the kidney. However, the pace of progression of these changes is not identical in everyone - individuals of the same age and seemingly similar clinical profile often exhibit stark differences in the age-related decline in renal health. Thus, chronological age poorly reflects the time-dependent changes that occur in the kidney. An ideal measure of renal vitality is biological kidney age – a measure of the age-related changes in physiological function. Replacing chronological age with biological age could provide numerous clinical benefits including improved prognostic accuracy in renal transplantation, better stratification of risk and identification of those who are on a fast trajectory to an age-related drop in kidney health.

Renal Cu and Na excretion and hepatic Cu metabolism in both Cu acclimated and non acclimated rainbow trout (Oncorhynchus mykiss)

DEFF Research Database (Denmark)

Grosell, M.; Hogstrand, C.; Wood, C.M.

1998-01-01

protein depending on whether the Cu is derived from recent branchial uptake or is already present in the plasma prior to Cu-64 exposure. The plasma Cu pool derived from recent branchial uptake and the Cu pool present in the plasma prior to Cu-64 exposure is accessible to renal excretion to different...... Na+ efflux decreased by 40%, which was largely due to increased tubular Na+ reabsorption. Renal compensation for the impaired branchial Na+ uptake, seen during Cu exposure, thus seems to be involved in Cu acclimation in rainbow trout. (C) 1998 Elsevier Science B.V....

Urinary Excretion of Tetrodotoxin Modeled in a Porcine Renal Proximal Tubule Epithelial Cell Line, LLC-PK1

Directory of Open Access Journals (Sweden)

Takuya Matsumoto

2017-07-01

Full Text Available This study examined the urinary excretion of tetrodotoxin (TTX modeled in a porcine renal proximal tubule epithelial cell line, LLC-PK1. Time course profiles of TTX excretion and reabsorption across the cell monolayers at 37 °C showed that the amount of TTX transported increased linearly for 60 min. However, at 4 °C, the amount of TTX transported was approximately 20% of the value at 37 °C. These results indicate that TTX transport is both a transcellular and carrier-mediated process. Using a transport inhibition assay in which cell monolayers were incubated with 50 µM TTX and 5 mM of a transport inhibitor at 37 °C for 30 min, urinary excretion was significantly reduced by probenecid, tetraethylammonium (TEA, l-carnitine, and cimetidine, slightly reduced by p-aminohippuric acid (PAH, and unaffected by 1-methyl-4-phenylpyridinium (MPP+, oxaliplatin, and cefalexin. Renal reabsorption was significantly reduced by PAH, but was unaffected by probenecid, TEA and l-carnitine. These findings indicate that TTX is primarily excreted by organic cation transporters (OCTs and organic cation/carnitine transporters (OCTNs, partially transported by organic anion transporters (OATs and multidrug resistance-associated proteins (MRPs, and negligibly transported by multidrug and toxic compound extrusion transporters (MATEs.

Effects of acute hypoxia on renal and endocrine function at rest and during graded exercise in hydrated subjects

DEFF Research Database (Denmark)

Olsen, Niels Vidiendal; Kanstrup, I L; Richalet, J P

1992-01-01

Renal effects of altitude hypoxia are unclear. Renal and hormonal function was investigated in eight males at rest and during graded exercise at sea level (SL) and 48 h after rapid ascent to 4,350 m (HA). HA did not change resting values of effective renal plasma flow (ERPF), glomerular filtration...... rate (GFR), sodium clearance (CNa), urine flow, or lithium clearance (CLi), which was used as an index of proximal tubular outflow. At rest, HA increased plasma norepinephrine concentration and decreased plasma concentrations of renin and aldosterone. Exercise decreased ERPF similarly in both...... environments. Normoxic exercise progressively reduced GFR, but at HA GFR only decreased during heavy exercise. This resulted in a higher filtration fraction during light and moderate hypoxic exercise. However, calculated absolute proximal reabsorption rate (GFR-CLi) at HA was higher during low...

Renal handling of technetium-99m DMSA: Evidence for glomerular filtration and peritubular uptake

International Nuclear Information System (INIS)

de Lange, M.J.; Piers, D.A.; Kosterink, J.G.; van Luijk, W.H.; Meijer, S.; de Zeeuw, D.; van der Hem, G.K.

1989-01-01

The finding of an enhanced excretion of [ 99m Tc]dimercaptosuccinic acid (DMSA) in patients with tubular reabsorption disorders prompted us to investigate the role of filtration in the renal handling of [ 99m Tc]DMSA. Our studies in human serum indicated that binding to serum proteins was approximately 90%. Chromatography of human urine and studies in rats showed that the complex was excreted unaltered into the urine. Renal extraction of [ 99m Tc]DMSA in a human volunteer was 5.8%. Continuous infusion of [ 99m Tc]DMSA in 13 individuals with normal renal function gave the following results (mean +/- s.d.): plasma clearance of [ 99m Tc]DMSA 34 +/- 4 ml/min, urinary clearance of [ 99m Tc]DMSA 12 +/- 3 ml/min. The calculated filtered load of [ 99m Tc]DMSA closely resembled the urinary clearance, whereas the plasma clearance was about three times faster. This indicates that peritubular uptake accounts for approximately 65% and filtration for approximately 35% of the renal handling of [ 99m Tc]DMSA

[Nephrogenic diabetes insipidus].

Science.gov (United States)

Velásquez-Jones, Luis; Medeiros-Domingo, Mara

The anti-diuretic hormone arginine-vasopressin (AVP) is released from the pituitary and regulates water reabsorption in the principal cells of the kidney collecting duct. Binding of AVP to the arginine-vasopressin receptor type-2 in the basolateral membrane leads to translocation of aquaporin-2 water channels to the apical membrane of the principal cells of the collecting duct, inducing water permeability of the membrane. This results in water reabsorption in the collecting duct of the nephron following an osmotic gradient. Nephrogenic diabetes insipidus is caused by partial or complete renal resistance to the effects of AVP. Congenital nephrogenic diabetes insipidus is a disorder associated with mutations in either the AVPR2 or AQP2 gene, causing the inability of patients to concentrate their urine. Acquired nephrogenic diabetes insipidus can be caused by electrolyte imbalances (e.g., hypercalcemia, hypokalemia), renal/extra-renal diseases and drugs (e.g., lithium toxicity). This article reviews the causes, clinical manifestations, diagnosis and treatment of patients with nephrogenic diabetes insipidus. Based on more in-depth mechanistic understanding, new therapeutic strategies are current being explored. Copyright © 2014 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Mini-review: regulation of the renal NaCl cotransporter by hormones.

Science.gov (United States)

Rojas-Vega, Lorena; Gamba, Gerardo

2016-01-01

The renal thiazide-sensitive NaCl cotransporter, NCC, is the major pathway for salt reabsorption in the distal convoluted tubule. The activity of this cotransporter is critical for regulation of several physiological variables such as blood pressure, serum potassium, acid base metabolism, and urinary calcium excretion. Therefore, it is not surprising that numerous hormone-signaling pathways regulate NCC activity to maintain homeostasis. In this review, we will provide an overview of the most recent evidence on NCC modulation by aldosterone, angiotensin II, vasopressin, glucocorticoids, insulin, norepinephrine, estradiol, progesterone, prolactin, and parathyroid hormone. Copyright © 2016 the American Physiological Society.

Renal MR angiography and perfusion in the pig using hyperpolarized water.

Science.gov (United States)

Wigh Lipsø, Kasper; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling; Laustsen, Christoffer; Ardenkjaer-Larsen, Jan Henrik

2017-09-01

To study hyperpolarized water as an angiography and perfusion tracer in a large animal model. Protons dissolved in deuterium oxide (D 2 O) were hyperpolarized in a SPINlab dissolution dynamic nuclear polarization (dDNP) polarizer and subsequently investigated in vivo in a pig model at 3 Tesla (T). Approximately 15 mL of hyperpolarized water was injected in the renal artery by hand over 4-5 s. A liquid state polarization of 5.3 ± 0.9% of 3.8 M protons in 15 mL of deuterium oxide was achieved with a T 1 of 24 ± 1 s. This allowed injection through an arterial catheter into the renal artery and subsequently high-contrast imaging of the entire kidney parenchyma over several seconds. The dynamic images allow quantification of tissue perfusion, with a mean cortical perfusion of 504 ± 123 mL/100 mL/min. Hyperpolarized water MR imaging was successfully demonstrated as a renal angiography and perfusion method. Quantitative perfusion maps of the kidney were obtained in agreement with literature and control experiments with gadolinium contrast. Magn Reson Med 78:1131-1135, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Direct effect of methylprednisolone on renal sodium and water transport via the principal cells in the kidney

DEFF Research Database (Denmark)

Lauridsen, Thomas G; Vase, Henrik; Bech, Jesper N

2010-01-01

Glucocorticoids influence renal concentrating and diluting ability. We tested the hypothesis that methylprednisolone treatment increased renal water and sodium absorption by increased absorption via the aquaporin-2 (AQP2) water channels and the epithelial sodium channels (ENaCs) respectively....

Metabolic and hemodynamic effects of sodium-dependent glucose cotransporter 2 inhibitors on cardio-renal protection in the treatment of patients with type 2 diabetes mellitus.

Science.gov (United States)

Kashiwagi, Atsunori; Maegawa, Hiroshi

2017-07-01

The specific sodium-glucose cotransporter 2 inhibitors (SGLT2 inhibitors) inhibit glucose reabsorption in proximal renal tubular cells, and both fasting and postprandial glucose significantly decrease because of urinary glucose loss. As a result, pancreatic β-cell function and peripheral insulin action significantly improve with relief from glucose toxicity. Furthermore, whole-body energy metabolism changes to relative glucose deficiency and triggers increased lipolysis in fat cells, and fatty acid oxidation and then ketone body production in the liver during treatment with SGLT2 inhibitors. In addition, SGLT2 inhibitors have profound hemodynamic effects including diuresis, dehydration, weight loss and lowering blood pressure. The most recent findings on SGLT2 inhibitors come from results of the Empagliflozin, Cardiovascular Outcomes and Mortality in Type 2 Diabetes trial. SGLT2 inhibitors exert extremely unique and cardio-renal protection through metabolic and hemodynamic effects, with long-term durability on the reduction of blood glucose, bodyweight and blood pressure. Although a site of action of SGLT2 inhibitors is highly specific to inhibit renal glucose reabsorption, whole-body energy metabolism, and hemodynamic and renal functions are profoundly modulated during the treatment of SGLT2 inhibitors. Previous studies suggest multifactorial clinical benefits and safety concerns of SGLT2 inhibitors. Although ambivalent clinical results of this drug are still under active discussion, the present review summarizes promising recent evidence on the cardio-renal and metabolic benefits of SGLT2 inhibitors in the treatment of type 2 diabetes. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

OBESITY-INDUCED HYPERTENSION: INTERACTION OF NEUROHUMORAL AND RENAL MECHANISMS

Science.gov (United States)

Hall, John E.; do Carmo, Jussara M.; da Silva, Alexandre A.; Wang, Zhen; Hall, Michael E.

2015-01-01

Excess weight gain, especially when associated with increased visceral adiposity, is a major cause of hypertension, accounting for 65–75% of the risk for human primary (essential) hypertension. Increased renal tubular sodium reabsorption impairs pressure natriuresis and plays an important role in initiating obesity hypertension. The mediators of abnormal kidney function and increased blood pressure during development of obesity hypertension include 1) physical compression of the kidneys by fat in and around the kidneys, 2) activation of the renin-angiotensin-aldosterone system (RAAS), and 3) increased sympathetic nervous system (SNS) activity. Activation of the RAAS system is likely due, in part, to renal compression as well as SNS activation. However, obesity also causes mineralocorticoid receptor activation independent of aldosterone or angiotensin II. The mechanisms for SNS activation in obesity have not been fully elucidated but appear to require leptin and activation of the brain melanocortin system. With prolonged obesity and development of target organ injury, especially renal injury, obesity-associated hypertension becomes more difficult to control, often requiring multiple antihypertensive drugs and treatment of other risk factors, including dyslipidemia, insulin resistance and diabetes, and inflammation. Unless effective anti-obesity drugs are developed, the impact of obesity on hypertension and related cardiovascular, renal and metabolic disorders is likely to become even more important in the future as the prevalence of obesity continues to increase. PMID:25767285

Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria

Directory of Open Access Journals (Sweden)

E.V. Seliverstova

2015-04-01

Full Text Available The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endosomes, and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intracellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals.

Renal tubular dysfunction nephrocalcinosis in a patient with BetaThalassemia Minor

International Nuclear Information System (INIS)

Prabahar, M.R.; Jain, M.; Chandrasekaran, V.; Indumathi, E.; Soundrarajan, P.

2008-01-01

Thalassemia is a hereditary anemia resulting from defect in hemoglobinproduction. Beta thalassemia is due to impaired production. Beta thalassemiais due to impaired production of beta globin chains, leading to a relativeexcess of alpha globin chains. The term beta thalassemia minor is used todescribe heterozygotes, who carry one normal beta globin and one betathalassemic allele. The vast majority of these patients are asymptomatic.However, a variety of renal tubular abnormalities including hypercaliuria,hypomagnesemia with renal magnesium wasting, decreased tubular absorption ofphosphorous, hypouricemia with renal uric acid wasting, renal glycosuria andtubular proteinuria have been described even in patients with betathalassemia minor. We here in report a 24-year old patient who was found tohave thalassemia minor and nephrocalcinosis with evidence of renal tubulardysfunction. Investigations revealed normal renal function, hypercalciuria,reduced tubular reabsorption of phosphorous, hypomagnesemia and renalmagnesium wasting. Screening for aminoaciduria was found to be negative. Anacid loading test revealed normal urinary acidification. Ultrasonogram of theabdomen revealed nephrocalcinosis and splenomegaly. Detailed work up foranemia showed normal white cell and platelet count while peripheral smearshowed microcytic hypochromic anemia with few target cells. Hemoglobinelectrophoresis revealed hemoglobin A of 92%, hemoglobin A2 of 6.2% andhemoglobin F of 1.8% consistent with beta thalassemia minor. Her parentalscreening was normal. A diagnosis of beta thalassemia minor with renaltubular dysfunction was made and the patient was started on thiazidediuretics to reduce hypercalciuria and advised regular follow-up. (author)

Adenosine contribution to normal renal physiology and chronic kidney disease.

Science.gov (United States)

Oyarzún, Carlos; Garrido, Wallys; Alarcón, Sebastián; Yáñez, Alejandro; Sobrevia, Luis; Quezada, Claudia; San Martín, Rody

2017-06-01

Adenosine is a nucleoside that is particularly interesting to many scientific and clinical communities as it has important physiological and pathophysiological roles in the kidney. The distribution of adenosine receptors has only recently been elucidated; therefore it is likely that more biological roles of this nucleoside will be unveiled in the near future. Since the discovery of the involvement of adenosine in renal vasoconstriction and regulation of local renin production, further evidence has shown that adenosine signaling is also involved in the tubuloglomerular feedback mechanism, sodium reabsorption and the adaptive response to acute insults, such as ischemia. However, the most interesting finding was the increased adenosine levels in chronic kidney diseases such as diabetic nephropathy and also in non-diabetic animal models of renal fibrosis. When adenosine is chronically increased its signaling via the adenosine receptors may change, switching to a state that induces renal damage and produces phenotypic changes in resident cells. This review discusses the physiological and pathophysiological roles of adenosine and pays special attention to the mechanisms associated with switching homeostatic nucleoside levels to increased adenosine production in kidneys affected by CKD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hyperactivation of Nrf2 in early tubular development induces nephrogenic diabetes insipidus

Science.gov (United States)

Suzuki, Takafumi; Seki, Shiori; Hiramoto, Keiichiro; Naganuma, Eriko; Kobayashi, Eri H.; Yamaoka, Ayaka; Baird, Liam; Takahashi, Nobuyuki; Sato, Hiroshi; Yamamoto, Masayuki

2017-01-01

NF-E2-related factor-2 (Nrf2) regulates cellular responses to oxidative and electrophilic stress. Loss of Keap1 increases Nrf2 protein levels, and Keap1-null mice die of oesophageal hyperkeratosis because of Nrf2 hyperactivation. Here we show that deletion of oesophageal Nrf2 in Keap1-null mice allows survival until adulthood, but the animals develop polyuria with low osmolality and bilateral hydronephrosis. This phenotype is caused by defects in water reabsorption that are the result of reduced aquaporin 2 levels in the kidney. Renal tubular deletion of Keap1 promotes nephrogenic diabetes insipidus features, confirming that Nrf2 activation in developing tubular cells causes a water reabsorption defect. These findings suggest that Nrf2 activity should be tightly controlled during development in order to maintain renal homeostasis. In addition, tissue-specific ablation of Nrf2 in Keap1-null mice might create useful animal models to uncover novel physiological functions of Nrf2. PMID:28233855

Acute renal response to rapid onset respiratory acidosis.

Science.gov (United States)

Ramadoss, Jayanth; Stewart, Randolph H; Cudd, Timothy A

2011-03-01

Renal strong ion compensation to chronic respiratory acidosis has been established, but the nature of the response to acute respiratory acidosis is not well defined. We hypothesized that the response to acute respiratory acidosis in sheep is a rapid increase in the difference in renal fractional excretions of chloride and sodium (Fe(Cl) - Fe(Na)). Inspired CO(2) concentrations were increased for 1 h to significantly alter P(a)CO(2) and pH(a) from 32 ± 1 mm Hg and 7.52 ± 0.02 to 74 ± 2 mm Hg and 7.22 ± 0.02, respectively. Fe(Cl) - Fe(Na) increased significantly from 0.372 ± 0.206 to 1.240 ± 0.217% and returned to baseline at 2 h when P(a)CO(2) and pH(a) were 37 ± 0.6 mm Hg and 7.49 ± 0.01, respectively. Arterial pH and Fe(Cl) - Fe(Na) were significantly correlated. We conclude that the kidney responds rapidly to acute respiratory acidosis, within 30 min of onset, by differential reabsorption of sodium and chloride.

Stimulation of renal afferent fibers leads to activation of catecholaminergic and non-catecholaminergic neurons in the medulla oblongata.

Science.gov (United States)

Nishi, Erika E; Martins, Beatriz S; Milanez, Maycon I O; Lopes, Nathalia R; de Melo, Jose F; Pontes, Roberto B; Girardi, Adriana C; Campos, Ruy R; Bergamaschi, Cássia T

2017-05-01

Presympathetic neurons in the rostral ventrolateral medulla (RVLM) including the adrenergic cell groups play a major role in the modulation of several reflexes required for the control of sympathetic vasomotor tone and blood pressure (BP). Moreover, sympathetic vasomotor drive to the kidneys influence natriuresis and diuresis by inhibiting the cAMP/PKA pathway and redistributing the Na + /H + exchanger isoform 3 (NHE3) to the body of the microvilli in the proximal tubules. In this study we aimed to evaluate the effects of renal afferents stimulation on (1) the neurochemical phenotype of Fos expressing neurons in the medulla oblongata and (2) the level of abundance and phosphorylation of NHE3 in the renal cortex. We found that electrical stimulation of renal afferents increased heart rate and BP transiently and caused activation of tyrosine hydroxylase (TH)-containing neurons in the RVLM and non-TH neurons in the NTS. Additionally, activation of the inhibitory renorenal reflex over a 30-min period resulted in increased natriuresis and diuresis associated with increased phosphorylation of NHE3 at serine 552, a surrogate for reduced activity of this exchanger, in the contralateral kidney. This effect was not dependent of BP changes considering that no effects on natriuresis or diuresis were found in the ipsilateral-stimulated kidney. Therefore, our data show that renal afferents leads to activation of catecholaminergic and non-catecholaminergic neurons in the medulla oblongata. When renorenal reflex is induced, NHE3 exchanger activity appears to be decreased, resulting in decreased sodium and water reabsorption in the contralateral kidney. Copyright © 2017 Elsevier B.V. All rights reserved.

Renal tubular NHE3 is required in the maintenance of water and sodium chloride homeostasis.

Science.gov (United States)

Fenton, Robert A; Poulsen, Søren B; de la Mora Chavez, Samantha; Soleimani, Manoocher; Dominguez Rieg, Jessica A; Rieg, Timo

2017-08-01

The sodium/proton exchanger isoform 3 (NHE3) is expressed in the intestine and the kidney, where it facilitates sodium (re)absorption and proton secretion. The importance of NHE3 in the kidney for sodium chloride homeostasis, relative to the intestine, is unknown. Constitutive tubule-specific NHE3 knockout mice (NHE3 loxloxCre) did not show significant differences compared to control mice in body weight, blood pH or bicarbonate and plasma sodium, potassium, or aldosterone levels. Fluid intake, urinary flow rate, urinary sodium/creatinine, and pH were significantly elevated in NHE3 loxloxCre mice, while urine osmolality and GFR were significantly lower. Water deprivation revealed a small urinary concentrating defect in NHE3 loxloxCre mice on a control diet, exaggerated on low sodium chloride. Ten days of low or high sodium chloride diet did not affect plasma sodium in control mice; however, NHE3 loxloxCre mice were susceptible to low sodium chloride (about -4 mM) or high sodium chloride intake (about +2 mM) versus baseline, effects without differences in plasma aldosterone between groups. Blood pressure was significantly lower in NHE3 loxloxCre mice and was sodium chloride sensitive. In control mice, the expression of the sodium/phosphate co-transporter Npt2c was sodium chloride sensitive. However, lack of tubular NHE3 blunted Npt2c expression. Alterations in the abundances of sodium/chloride cotransporter and its phosphorylation at threonine 58 as well as the abundances of the α-subunit of the epithelial sodium channel, and its cleaved form, were also apparent in NHE3 loxloxCre mice. Thus, renal NHE3 is required to maintain blood pressure and steady-state plasma sodium levels when dietary sodium chloride intake is modified. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Reduced reabsorption and enhanced propagation induced by large Stokes shift in quantum dot-filled optical fiber

Energy Technology Data Exchange (ETDEWEB)

Wu, Hua; Zhang, Yu, E-mail: yuzhang@jlu.edu.cn; Lu, Min; Liu, Wenyan [Jilin University, State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering (China); Xu, Jian [The Pennsylvania State University, Department of Engineering Science and Mechanics (United States); Yu, William W., E-mail: wyu6000@gmail.com [Jilin University, State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering (China)

2016-07-15

With tunable emission wavelength, high photoluminescence quantum yield, and broad absorption, colloidal quantum dots are attractive for the application in optical fiber as dopants. However, most of the quantum dots have a large overlap between their absorption and photoluminescence spectra, resulting in reabsorption loss which hinders the realization of long-distance waveguides. Therefore, ZnCuInS/ZnSe/ZnS quantum dots with large Stokes shift were proposed to fabricate a liquid-core optical fiber in this work. In this work, ZnCuInS/ZnSe/ZnS QDs with an average size of 3.3 nm were synthesized and the optical properties of the QD-filled fiber were also investigated as a function of fiber length and doping concentration. Compared to the control sample filled with CdSe/CdS/ZnS quantum dots, the ZnCuInS/ZnSe/ZnS quantum dot-based waveguides showed reduced reabsorption and enhanced signal propagation, which demonstrates great potential of large Stokes-shift quantum dots in optical waveguide devices.Graphical AbstractA reduced reabsorption and enhanced propagation of ZnCuInS/ZnSe/ZnS QDs-doped liquid-core optical fiber was achieved due to the large Stokes shift.

Lithium clearance and renal tubular sodium handling during acute and long-term nifedipine treatment in essential hypertension

DEFF Research Database (Denmark)

Bruun, N E; Ibsen, H; Skøtt, P

1988-01-01

1. In two separate studies the lithium clearance method was used to evaluate the influence of acute and long-term nifedipine treatment on renal tubular sodium reabsorption. 2. In the acute study, after a 4 week placebo period two doses of 20 mg of nifedipine decreased supine blood pressure from 155...... were also unchanged, as were potassium clearance, urine flow and body weight. 3. In the long-term study, lithium clearance, glomerular filtration rate, sodium clearance, potassium clearance, urine flow and body fluid volumes were measured after a 4 weeks placebo period and after 6 and 12 weeks....../101 (20.6/13.5) +/- 11/4 (1.5/0.5) to 139/88 (18.5/11.7) +/- 16/9 (2.1/1.2) mmHg (kPa) (means +/- SD; P less than 0.01). Lithium clearance, glomerular filtration rate and sodium clearance did not change. Therefore the calculated values of absolute proximal and absolute distal sodium reabsorption rates...

Human Sodium Phosphate Transporter 4 (hNPT4/SLC17A3) as a Common Renal Secretory Pathway for Drugs and Urate*

Science.gov (United States)

Jutabha, Promsuk; Anzai, Naohiko; Kitamura, Kenichiro; Taniguchi, Atsuo; Kaneko, Shuji; Yan, Kunimasa; Yamada, Hideomi; Shimada, Hidetaka; Kimura, Toru; Katada, Tomohisa; Fukutomi, Toshiyuki; Tomita, Kimio; Urano, Wako; Yamanaka, Hisashi; Seki, George; Fujita, Toshiro; Moriyama, Yoshinori; Yamada, Akira; Uchida, Shunya; Wempe, Michael F.; Endou, Hitoshi; Sakurai, Hiroyuki

2010-01-01

The evolutionary loss of hepatic urate oxidase (uricase) has resulted in humans with elevated serum uric acid (urate). Uricase loss may have been beneficial to early primate survival. However, an elevated serum urate has predisposed man to hyperuricemia, a metabolic disturbance leading to gout, hypertension, and various cardiovascular diseases. Human serum urate levels are largely determined by urate reabsorption and secretion in the kidney. Renal urate reabsorption is controlled via two proximal tubular urate transporters: apical URAT1 (SLC22A12) and basolateral URATv1/GLUT9 (SLC2A9). In contrast, the molecular mechanism(s) for renal urate secretion remain unknown. In this report, we demonstrate that an orphan transporter hNPT4 (human sodium phosphate transporter 4; SLC17A3) was a multispecific organic anion efflux transporter expressed in the kidneys and liver. hNPT4 was localized at the apical side of renal tubules and functioned as a voltage-driven urate transporter. Furthermore, loop diuretics, such as furosemide and bumetanide, substantially interacted with hNPT4. Thus, this protein is likely to act as a common secretion route for both drugs and may play an important role in diuretics-induced hyperuricemia. The in vivo role of hNPT4 was suggested by two hyperuricemia patients with missense mutations in SLC17A3. These mutated versions of hNPT4 exhibited reduced urate efflux when they were expressed in Xenopus oocytes. Our findings will complete a model of urate secretion in the renal tubular cell, where intracellular urate taken up via OAT1 and/or OAT3 from the blood exits from the cell into the lumen via hNPT4. PMID:20810651

Peripheral arterial vasodilation hypothesis: a proposal for the initiation of renal sodium and water retention in cirrhosis

DEFF Research Database (Denmark)

Schrier, R W; Arroyo, V; Bernardi, M

1988-01-01

Renal sodium and water retention and plasma volume expansion have been shown to precede ascites formation in experimental cirrhosis. The classical "underfilling" theory, in which ascites formation causes hypovolemia and initiates secondary renal sodium and water retention, thus seems unlikely...... with cirrhosis. Arterial vasodilators and arteriovenous fistula are other examples in which renal sodium and water retention occur secondary to a decreased filling of the arterial vascular tree. An increase in cardiac output and hormonal stimulation are common features of cirrhosis, arteriovenous fistula...... and drug-induced peripheral arterial vasodilation. However, a predilection for the retained sodium and water to transudate into the abdominal cavity occurs with cirrhosis because of the presence of portal hypertension. The Peripheral Arterial Vasodilation Hypothesis also explains the continuum from...

Renal glucose handling in diabetes and sodium glucose cotransporter 2 inhibition

Directory of Open Access Journals (Sweden)

Resham Raj Poudel

2013-01-01

Full Text Available The kidneys play a major role in glucose homeostasis through its utilization, gluconeogenesis, and reabsorption via sodium glucose cotransporters (SGLTs. The defective renal glucose handling from upregulation of SGLTs, mainly the SGLT2, plays a fundamental role in the pathogenesis of type 2 diabetes mellitus. Genetic mutations in a SGLT2 isoform that results in benign renal glycosuria, as well as clinical studies with SGLT2 inhibitors in type 2 diabetes support the potential of this approach. These studies indicate that inducing glycosuria by suppressing SGLT2 can reduce plasma glucose and A1c levels, as well as decrease weight, resulting in improved β-cell function and enhanced insulin sensitivity in liver and muscle. Because the mechanism of SGLT2 inhibition is independent of insulin secretion and sensitivity, these agents can be combined with other antidiabetic agents, including exogenous insulin. This class represents a novel therapeutic approach with potential for the treatment of both type 2 and type 1 diabetes.

Hydrochlorothiazide-induced 131I excretion facilitated by salt and water

International Nuclear Information System (INIS)

Beyer, K.H. Jr.; Fehr, D.M.; Gelarden, R.T.; White, W.J.; Lang, C.M.; Vesell, E.S.

1981-01-01

Salt intake is restricted under clinical conditions for which thiazide diuretics are customarily used. Dietary iodide intake offsets any effect of thiazide on iodide loss. However, our correlation coefficients relating Na+ to Cl- to I- excretion indicate that as thiazide administration or sodium chloride intake increases renal Na+ and Cl- excretion, I- reabsorption by the nephron coordinately decreases. Increased sodium chloride and water intake by the dog doubled I-excretion rates. Hydrochlorothiazide increased the sodium chloride and water enhanced I-excretion rate as much as eight-fold. Without added NaCl, hydrochlorothiazide increased the excretion rate of 131I by three- to eightfold, acutely. Within five to seven days after 131I oral administration, hydrochlorothiazide (1 or 2 mg/kg twice daily) doubled the rate of 131I disappearance from plasma, reduced the fecal output of 131I, and increased its rate of renal excretion. When hydrochlorothiazide was administered, as much 131I was excreted in the first 24 hours as occurred in 48 hours when sodium chloride and water were given without hydrochlorothiazide. Thiazide administration in customary clinical dosage twice a day with substantial sodium chloride and water for the first two days after exposure to 131I, should therefore facilitate the safe excretion of 131I. This accelerated removal of 131I might be enhanced even more if thyroid uptake of 131I is blocked by administration of potassium iodide, as judged by the greater 131I recovery from thyroidectomized dogs

Estimation of rumen microbial protein production from urinary purine derivatives in zebu cattle and water buffalo

International Nuclear Information System (INIS)

Liang, J.B.; Pimpa, O.; Abdullah, N.; Jelan, Z.A.; Nolan, J.V.

1999-01-01

Two experiments were conducted in order to develop equations for predicting rumen microbial protein production for indigenous Kedah-Kelantan (KK) cattle and swamp buffaloes in Malaysia, using urinary purine derivatives (PD) excretion rates. Endogenous PD excretion rates determined by a fasting procedure for KK cattle and swamp buffalo were 275 and 370 μmol/kg W 0.75 /day, respectively. Urinary PD excretion rate per kg digestible organic matter intake (DOMI) for KK cattle was higher than that for swamp buffalo, reconfirming the earlier findings. Glomerular filtration rate, allantoin and uric acid tubular load and PD re-absorption rate for swamp buffalo were generally higher than those for KK cattle. However, due to the large variations among animals within species, these parameters were not significantly different between species. Nevertheless, the higher PD reabsorption in swamp buffalo provides support for the earlier postulation that the lower urinary PD excretion rate of swamp buffalo was due to their higher recycling of plasma PD as compared to KK cattle. Labelled 8- 14 C uric acid was used to estimate the ratio of renal to non-renal PD excretion. The recovery rates of the radioactive tracer via the renal route for both species were much lower than values reported previously for unlabelled PD for European cattle. (author)

Mechanistic insights of intestinal absorption and renal conservation of folate in chronic alcoholism.

Science.gov (United States)

Wani, Nissar Ahmad; Thakur, Shilpa; Najar, Rauf Ahmad; Nada, Ritambhara; Khanduja, Krishan Lal; Kaur, Jyotdeep

2013-03-01

Folate mediated one-carbon metabolism is of fundamental importance for various cellular processes, including DNA synthesis and methylation of biological molecules. Due to the exogenous requirement of folate in mammals, there exists a well developed epithelial folate transport system for regulation of normal folate homeostasis. The intestinal and renal folate uptake is tightly and diversely regulated and disturbances in folate homeostasis like in alcoholism have pathological consequences. The study was sought to delineate the regulatory mechanism of folate uptake in intestine and reabsorption in renal tubular cells that could evaluate insights of malabsorption during alcoholism. The folate transporters PCFT and RFC were found to be associated with lipid rafts of membrane surfaces in intestine and kidney. Importantly, the observed lower intestinal and renal folate uptake was associated with decreased levels of folate transporter viz. PCFT and RFC in lipid rafts of intestinal and renal membrane surfaces. The decreased association of folate transporters in lipid rafts was associated with decreased protein and mRNA levels. In addition, immunohistochemical studies showed that alcoholic conditions deranged that localization of PCFT and RFC. These findings could explain the possible mechanistic insights that may result in folate malabsorption during alcoholism. Copyright © 2013 Elsevier Inc. All rights reserved.

Insulin's acute effects on glomerular filtration rate correlate with insulin sensitivity whereas insulin's acute effects on proximal tubular sodium reabsorption correlate with salt sensitivity in normal subjects

NARCIS (Netherlands)

ter Maaten, JC; Bakker, SJL; Serne, EH; ter Wee, PM; Gans, ROB

1999-01-01

Background. Insulin induces increasing distal tubular sodium reabsorption. Opposite effects of insulin to offset insulin-induced sodium retention are supposedly increases in glomerular filtration rate (GFR) and decreases in proximal tubular sodium reabsorption. Defects in these opposing effects

Ectopic germinal center and megalin defect in primary Sjogren syndrome with renal Fanconi syndrome.

Science.gov (United States)

Wang, Jing; Wen, Yubing; Zhou, Mengyu; Shi, Xiaoxiao; Jiang, Lanping; Li, Mingxi; Yu, Yang; Li, Xuemei; Li, Xuewang; Zhang, Wen; Lundquist, Andrew L; Chen, Limeng

2017-06-02

This study reports the clinical and pathological features of 12 cases of primary Sjogren syndrome (pSS) with renal involvement presenting with proximal tubular dysfunction in a single center, and investigates the possible correlation of ectopic germinal center formation and megalin/cubilin down-expression. Clinical and pathological records were reviewed. Immunohistochemistry was carried out to detect megalin, cubilin, CD21 and IL-17 expression. Patients presented with different degrees of proximal renal tubule lesion and decreased estimated glomerular filtration rate (eGFR). Renal biopsy revealed tubulointerstitial nephritis, with tubular epithelial cell degeneration, tubular atrophy, interstitial inflammation and focal fibrosis. Immunohistochemistry revealed decreased expression of megalin and cubilin, two important multiligand protein receptors on the brush border of proximal tubular epithelial cells. IL-17 secreted by Th17 subtype effector T cells was diffusely detected in the renal proximal tubule, with a negative correlation of IL-17 and megalin expression. In addition, ectopic germinal centers characterized by CD21 + follicular dendritic cells were present in the renal interstitium. In patients with a decreased eGFR, treatment with 4 weeks of glucocorticoid therapy resulted in an improved eGFR in 75% of patients. We report 12 cases of pSS characterized by Fanconi syndrome. The decreased megalin and cubilin expression may contribute to the proximal tubular reabsorption defect, possibly secondary to Th17 infiltration and formation of ectopic germinal centers.

The Association of Albuminuria With Tubular Reabsorption of Uric Acid : Results From a General Population Cohort

NARCIS (Netherlands)

Scheven, Lieneke; Joosten, Michel M.; de Jong, Paul E.; Bakker, Stephan J. L.; Gansevoort, Ron T.

Background-Elevated albuminuria as well as an increased serum uric acid concentration is associated with poor cardiovascular outcome. We questioned whether these 2 variables (albuminuria and serum uric concentration) may be interrelated via tubular uric acid reabsorption. Methods and

Renal handling of technetium-99m DMSA in rats with proximal tubular dysfunction

International Nuclear Information System (INIS)

Provoost, A.P.; Van Aken, M.

1985-01-01

The renal handling of technetium-/sup 99m/ dimercaptosuccinic acid ([/sup 99m/Tc]DMSA) was studied in rats before and after treatment with Na-maleate (2 mmol/kg i.v.). In the control period, when measured 2 hr after the intravenous injection of [/sup 99m/Tc]DMSA, 39.9% of the injected dose was in the kidneys and 14.6% was in the bladder. After Na-maleate treatment, only 6.4% of the injected dose of [/sup 99m/Tc]DMSA was retained in the kidneys while 37.9% was found in the bladder. Subsequent studies revealed that Na-maleate produced a fall in the glomerular filtration rate, the effective renal plasma flow, and a generalized proximal tubular dysfunction. The latter was characterized by polyuria and an increased excretion of glucose, protein, albumin, calcium, and inorganic phosphate. It was concluded that proximal tubular dysfunction markedly alters the renal handling of [/sup 99m/Tc]DMSA. Whether this augmented urinary excretion is due to an inhibition of reabsorption or an enhanced cellular efflux of [/sup 99m/Tc]DMSA remains to be answered

Role of NH3 and NH4+ transporters in renal acid-base transport.

Science.gov (United States)

Weiner, I David; Verlander, Jill W

2011-01-01

Renal ammonia excretion is the predominant component of renal net acid excretion. The majority of ammonia excretion is produced in the kidney and then undergoes regulated transport in a number of renal epithelial segments. Recent findings have substantially altered our understanding of renal ammonia transport. In particular, the classic model of passive, diffusive NH3 movement coupled with NH4+ "trapping" is being replaced by a model in which specific proteins mediate regulated transport of NH3 and NH4+ across plasma membranes. In the proximal tubule, the apical Na+/H+ exchanger, NHE-3, is a major mechanism of preferential NH4+ secretion. In the thick ascending limb of Henle's loop, the apical Na+-K+-2Cl- cotransporter, NKCC2, is a major contributor to ammonia reabsorption and the basolateral Na+/H+ exchanger, NHE-4, appears to be important for basolateral NH4+ exit. The collecting duct is a major site for renal ammonia secretion, involving parallel H+ secretion and NH3 secretion. The Rhesus glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), are recently recognized ammonia transporters in the distal tubule and collecting duct. Rhcg is present in both the apical and basolateral plasma membrane, is expressed in parallel with renal ammonia excretion, and mediates a critical role in renal ammonia excretion and collecting duct ammonia transport. Rhbg is expressed specifically in the basolateral plasma membrane, and its role in renal acid-base homeostasis is controversial. In the inner medullary collecting duct (IMCD), basolateral Na+-K+-ATPase enables active basolateral NH4+ uptake. In addition to these proteins, several other proteins also contribute to renal NH3/NH4+ transport. The role and mechanisms of these proteins are discussed in depth in this review.

Effects of water deprivation on renal hydroelectrolytic excretion in chronically Trypanosoma cruzi-infected rats

Directory of Open Access Journals (Sweden)

T.T. Rosa

1995-03-01

Full Text Available The effect of an 8 hour-period of water deprivation on fluid and electrolyte renal excretion was investigated in male Wistar rats infected with the strain São Felipe (12SF of Trypanosoma cruzi, in comparison with age and sex matched non-infected controls. The median percent reductions in the urinary flow (-40% v -63% and excretion ofsodium (-57% v-79% were smaller in chagasic than in control rats, respectively. So, chagasic rats excreted more than controls. On the other hand, the median percent decrement in the clearance of creatinine was higher in chagasic (-51% than in controls (-39%. Thus, chagasic rats showed some disturbed renal hydroelectrolytic responses to water deprivation, expressed by smaller conservation, or higher excretion of water and sodium in association with smaller glomerularfiltration rate. This fact denoted an elevation in the fractional excretion of sodium and water.

Quantification of renal cortical blood flow using factor analysis of O-15 water dynamic PET images

International Nuclear Information System (INIS)

Seo, Kang Jun; Ahn, Ji Young; Lee, Jae Sung; Paeng, Jin Chul; Cheon, Gi Jeong; Lee, Dong Soo; Noh, Tae Won; Chung, June Key; Lee, Myung Chul

2000-01-01

To obtain spatial distribution of renal factor images, input function, and regional tissue time-activity curve (TAC) from O-15 water dynamic PET images non-invasively, factor analysis (FA) was used. O-15 water dynamic PET scans were performed on 3 normal dogs (22 ∼ 29 kg) with the bolus injection of O-15 water (555 ∼ 740 Mbq). We performed FA on the masked dynamic images and obtained the pure TACs and the corresponding factor images. Microsphere experiment also was performed. 37MBq of microsphere labeled with Sc-46 was injected into the left ventricle. Arterial input functions derived from the PET images using FA were compared with the invasively derived arterial blood samples. The renal cortical blood flow using the TACs by FA was within the normal range of 1.23 ∼ 2.46 ml/min/g. In microsphere study, the renal cortical blood flow of left kidney by FA was 2.49±0.47 ml/min/g (1.81∼2.90 ml/min/g) and by microsphere was 2.52 ±0.19 ml/min/g (2.34 ∼2.68 ml/min/g). In right kidney, flow by FA was 2.02 ±0.32 ml/min/g (1.82∼2.49 ml/min/g) and by microsphere was 2.49 ±0.27 ml/min/g (2.02∼2.7). FA is a useful and robust method to extract input functions and tissue TACs from O-15 dynamic renal PET. Renal cortical blood flow can be estimated non-invasively using FA and it will be helpful for the assessment of renal functional disease

Inherited renal tubulopathies associated with metabolic alkalosis: effects on blood pressure.

Science.gov (United States)

Ariceta, Gema; Rodríguez-Soriano, Juan

2006-11-01

Inherited tubular disorders associated with metabolic alkalosis are caused by several gene mutations encoding different tubular transporters responsible for NaCl renal handling. Body volume and renin-angiotensin-aldosterone system status are determined by NaCl reabsorption in the distal nephron. Two common hallmarks in affected individuals: hypokalemia and normal / high blood pressure, support the differential diagnosis. Bartter's syndrome, characterized by hypokalemia and normal blood pressure, is a heterogenic disease caused by the loss of function of SLC12A1 (type 1), KCNJ1 (type 2), CLCNKB (type 3), or BSND genes (type 4). As a result, patients present with renal salt wasting and hypercalciuria. Gitelman's syndrome is caused by the loss of funcion of the SLC12A3 gene and may resemble Bartter's syndrome, though is associated with the very low urinary calcium. Liddle's syndrome, also with similar phenotype but with hypertension, is produced by the gain of function of the SNCC1B or SNCC1G genes, and must be distinguished from other entities of inherited hypertension such as Apparently Mineralocorticoid Excess, of glucocorticoid remediable hypertension.

The mythology of renal function measurement

International Nuclear Information System (INIS)

Britton, K.E.

2003-01-01

The kidney is a conservative organ. In principle it retains what the body needs, and what is not needed is excreted. It has a number of basic properties. It has the ability to take solutes up from the blood whether by filtration or secretion, which is best called its Uptake function. In the special circumstance where the kidneys are the only exit for the solute from the body, then the rate of loss from the blood is equal to the rate of uptake by the kidney. It has the ability to move solutes among its nephrons, which is its Transit function. The solutes may be absorbed in whole or part and be retained or returned to the blood, its Reabsorption function. In the special case where the solute is non- reabsorbable, then, if there is an increase in salt and water reabsorption as in functionally significant renovascular disease or obstructive nephropathy, the transit function is altered and the transit time through the parenchyme is prolonged. In renovascular disorder the transit time is prolonged through both cortical and juxta-medullary nephrons and collecting ducts. In obstructive nephropathy the transit time is prolonged through the cortical nephrons, but usually is shortened through the juxta-medullary nephrons and collecting ducts due to loss of medullary concentrating ability. After transit through the kidney, the solutes move through the pelvis and ureter, its Excretory function. No more can come out of the kidney then went in previously. If less comes out than what went in, then an increased resistance to outflow is predicted. The balance between excretory function and uptake function is measurable by the Output (Outflow) Efficiency. The kidney also has receptors for hormones, which may modify its reabsorptive functions, for example increased Vasopressin binding decreases the permeability of the collecting duct to water. The kidney also has the ability through enzymes to modify solutes, such as the activation of Vitamin D

Mathematical rationalization for the renal tubular transport: revised concepts.

Science.gov (United States)

Mioni, Roberto; Marega, Alessandra; Romano, Giulio; Montanaro, Domenico

2017-09-01

The current emphasis on kinetics and in situ control of molecular exchanges, across the tubular membrane, has not been paralleled by corresponding improvements in our understanding of tubular behaviour at the macroscopic level of classical physiology. In this paper, we propose a mathematical rationalization of macroscopic tubular transport by means of a principal transport equation, originating from the law of mass action between substrate and carrier. The other equations, derived from the main one, demonstrate the possibility of distinguishing between transporters with low affinity and high capacity and transporters with high affinity and low capacity. Moreover, our model formalizes both tubular reabsorption and tubular secretion. Regarding the renal calcium handling, our model confirms the two-compartment system proposed by Mioni in 1971, with some important variants, which are in agreement with the fractional reabsorptions of this cation along the tubule, as verified by micro-puncture technique. To obtain the frequency distribution of saturated tubules, we have utilized the infinitesimal analysis method, starting from the equations proposed by Smith in 1943, concluding that all titration curves result from the combined effect of enzymatic approach and anatomical heterogeneity of the nephrons. The theoretical equations included in our manuscript reflect substantial and palpable physiological mechanisms able to suggest diagnosis and therapy of some electrolyte and hormonal disorders. At the end of this paper, we highlight advantages and disadvantages detectable by comparing our mathematical approach with Marshall's and Bijvoet's methods, proposed, respectively, in 1976 and 1984.

Mechanisms controlling renal hemodynamics and electrolyte excretion during amino acids

International Nuclear Information System (INIS)

Woods, L.L.; Mizelle, H.L.; Montani, J.P.; Hall, J.E.

1986-01-01

Our purpose was to investigate the mechanisms by which increased plasma amino acids elevate renal blood flow (RBF) and glomerular filtration rate (GFR). Since transport of amino acids and Na + is linked in the proximal tubule, the authors hypothesized that increased amino acids might stimulate proximal tubular Na + reabsorption (PR/sub Na/) and thus increase RBF and GFR by a macula densa feedback mechanism. A solution of four amino acids (Ala, Ser, Gly, Pro) was infused intravenously into anesthetized dogs with normal kidneys (NK) and with kidneys in which the tubuloglomerular feedback mechanism was blunted by lowering renal artery pressure (LPK) or blocked by making the kidneys nonfiltering (NFK). In NK, RBF and GFR increased by 35 +/- 4% and 30 +/- 7% after 90 min of amino acid infusion, while PR/sub Na/ (estimated from lithium clearance) and O 2 consumption increased by 31 +/- 5% and 29 +/- 5% and distal Na + delivery remained relatively constant. Autoregulation of RBF and GFR in response to step deceases in renal artery pressure was impaired during amino acids in NK. The hemodynamic responses to amino acids were abolished in LPK and NFK. Infusion of the nonmetabolized α-aminoisobutyric acid into NK produced changes in renal hemodynamics that were similar to the responses observed with the four metabolizable amino acids. These data are consistent with the hypothesis that elevation of plasma amino acids increases RBF and GFR by a mechanism that requires an intact macula densa feedback. Metabolism of the amino acids does not appear to be necessary for these changes to occur

Mechanisms controlling renal hemodynamics and electrolyte excretion during amino acids

Energy Technology Data Exchange (ETDEWEB)

Woods, L.L.; Mizelle, H.L.; Montani, J.P.; Hall, J.E.

1986-08-01

Our purpose was to investigate the mechanisms by which increased plasma amino acids elevate renal blood flow (RBF) and glomerular filtration rate (GFR). Since transport of amino acids and Na is linked in the proximal tubule, the authors hypothesized that increased amino acids might stimulate proximal tubular Na reabsorption (PR/sub Na/) and thus increase RBF and GFR by a macula densa feedback mechanism. A solution of four amino acids (Ala, Ser, Gly, Pro) was infused intravenously into anesthetized dogs with normal kidneys (NK) and with kidneys in which the tubuloglomerular feedback mechanism was blunted by lowering renal artery pressure (LPK) or blocked by making the kidneys nonfiltering (NFK). In NK, RBF and GFR increased by 35 +/- 4% and 30 +/- 7% after 90 min of amino acid infusion, while PR/sub Na/ (estimated from lithium clearance) and O2 consumption increased by 31 +/- 5% and 29 +/- 5% and distal Na delivery remained relatively constant. Autoregulation of RBF and GFR in response to step deceases in renal artery pressure was impaired during amino acids in NK. The hemodynamic responses to amino acids were abolished in LPK and NFK. Infusion of the nonmetabolized -aminoisobutyric acid into NK produced changes in renal hemodynamics that were similar to the responses observed with the four metabolizable amino acids. These data are consistent with the hypothesis that elevation of plasma amino acids increases RBF and GFR by a mechanism that requires an intact macula densa feedback. Metabolism of the amino acids does not appear to be necessary for these changes to occur.

Oral Contraceptives and Renal Water Handling; A diurnal study in young women

DEFF Research Database (Denmark)

Graugaard-Jensen, Charlotte; Hvistendahl, Gitte M; Frøkiær, Jørgen

2017-01-01

To test the hypothesis that use of oral contraceptives (OC) changes diurnal variation in fluid balance mechanisms including blood pressure, secretion of vasopressin and oxytocin, and renal water and electrolyte excretion. Fifteen naturally cycling (NC) women in mid-follicular phase and 11 long-te...

Effect of angiotensin II receptor blockade on proximal tubular fluid reabsorption

DEFF Research Database (Denmark)

Leyssac, P P; Karlsen, F M; Holstein-Rathlou, N H

1997-01-01

flow rate decreased by 2.0 +/- 0.8 nl/min, and early distal NaCl concentration decreased by 4.3 +/- 0.8 mM (mean +/- SE). No changes were observed after microperfusion with saline. Because the tubuloglomerular feedback mechanism was operating in the closed-loop mode, the decreased NaCl load...... to the macula densa will be compensated by an increase in the single-nephron glomerular filtration rate. In agreement with this, the early proximal flow rate, measured proximal to the site of losartan administration, increased by 5.7 +/- 1.3 nl/min. The increase in the rate of proximal reabsorption between...

The renal effects of SGLT2 inhibitors and a mini-review of the literature.

Science.gov (United States)

Andrianesis, Vasileios; Glykofridi, Spyridoula; Doupis, John

2016-12-01

Sodium-glucose linked transporter 2 (SGLT2) inhibitors are a new and promising class of antidiabetic agents which target renal tubular glucose reabsorption. Their action is based on the blockage of SGLT2 sodium-glucose cotransporters that are located at the luminal membrane of tubular cells of the proximal convoluted tubule, inducing glucosuria. It has been proven that they significantly reduce glycated hemoglobin (HbA1c), along with fasting and postprandial plasma glucose in patients with type 2 diabetes mellitus (T2DM). The glucosuria-induced caloric loss as well as the osmotic diuresis significantly decrease body weight and blood pressure, respectively. Given that SGLT2 inhibitors do not interfere with insulin action and secretion, their efficacy is sustained despite the progressive β-cell failure in T2DM. They are well tolerated, with a low risk of hypoglycemia. Their most frequent adverse events are minor: genital and urinal tract infections. Recently, it was demonstrated that empagliflozin presents a significant cardioprotective effect. Although the SGLT2 inhibitors' efficacy is affected by renal function, new data have been presented that some SGLT2 inhibitors, even in mild and moderate renal impairment, induce significant HbA1c reduction. Moreover, recent data indicate that SGLT2 inhibition has a beneficial renoprotective effect. The role of this review paper is to explore the current evidence on the renal effects of SGLT2 inhibitors.

Evaluation of Renal Oxygenation Level Changes after Water Loading Using Susceptibility-Weighted Imaging and T2* Mapping.

Science.gov (United States)

Ding, Jiule; Xing, Wei; Wu, Dongmei; Chen, Jie; Pan, Liang; Sun, Jun; Xing, Shijun; Dai, Yongming

2015-01-01

To assess the feasibility of susceptibility-weighted imaging (SWI) while monitoring changes in renal oxygenation level after water loading. Thirty-two volunteers (age, 28.0 ± 2.2 years) were enrolled in this study. SWI and multi-echo gradient echo sequence-based T2(*) mapping were used to cover the kidney before and after water loading. Cortical and medullary parameters were measured using small regions of interest, and their relative changes due to water loading were calculated based on baseline and post-water loading data. An intraclass correlation coefficient analysis was used to assess inter-observer reliability of each parameter. A receiver operating characteristic curve analysis was conducted to compare the performance of the two methods for detecting renal oxygenation changes due to water loading. Both medullary phase and medullary T2(*) values increased after water loading (p T2(*) changes (p > 0.05). Interobserver reliability was excellent for the T2(*) values, good for SWI cortical phase values, and moderate for the SWI medullary phase values. The area under receiver operating characteristic curve of the SWI medullary phase values was 0.85 and was not different from the medullary T2(*) value (0.84). Susceptibility-weighted imaging enabled monitoring changes in the oxygenation level in the medulla after water loading, and may allow comparable feasibility to detect renal oxygenation level changes due to water loading compared with that of T2(*) mapping.

Long-term treatment with tenofovir in Asian-American chronic hepatitis B patients is associated with abnormal renal phosphate handling.

Science.gov (United States)

Tien, Connie; Xu, Jason J; Chan, Linda S; Chang, Mimi; Lim, Carolina; Lee, Sue; Huh, Brian; Shinada, Shuntaro; Bae, Ho S; Fong, Tse-Ling

2015-02-01

Increased risk of defective urinary phosphate reabsorption and osteoporosis has been reported in HIV and chronic hepatitis B (CHB) patients treated with tenofovir disoproxil fumarate (TDF). Goals of this study were to evaluate the prevalence of renal phosphate wasting and abnormal bone mineral density in CHB patients taking TDF compared to CHB patients treated with entecavir (ETV) and untreated CHB patients. This is a cross-sectional study of 146 consecutive Asian-American CHB patients who were treatment naïve (n = 60) or treated with either TDF (n = 42) or ETV (n = 44). Proximal tubular handling of phosphate was assessed by the maximal rate of tubular reabsorption of phosphate (TmPO4) divided by glomerular filtration rate (GFR) (TmPO4/GFR). Bone mineral density (BMD) was measured using dual X-ray absorptiometry. TmPO4/GFR was similar among CHB patients treated with TDF compared to untreated patients and patients taking ETV. However, among patients treated with ≥18 months of TDF or ETV, prevalence of abnormal TmPO4/GFR was higher among patients treated with TDF compared to ETV (48.5 % (16/33) vs. 12.5 % (3/24), p = 0.005). Overall prevalence of osteoporosis in this cohort of CHB patients was 14 %, with no significant difference between the three groups. Renal phosphate handling did not correlate with osteoporosis. Chronic hepatitis B patients treated with ≥18 months of TDF experienced an increased risk of proximal tubular dysfunction. TDF did not increase the risk of osteoporosis. Longitudinal studies are needed to confirm these findings.

Regulation of Mg2+ Reabsorption and Transient Receptor Potential Melastatin Type 6 Activity by cAMP Signaling.

NARCIS (Netherlands)

Blanchard, M.G.; Kittikulsuth, W.; Nair, A.V.; Baaij, J.H.F. de; Latta, F.; Genzen, J.R.; Kohan, D.E.; Bindels, R.J.M.; Hoenderop, J.G.J.

2016-01-01

The transient receptor potential melastatin type 6 (TRPM6) epithelial Mg(2+) channels participate in transcellular Mg(2+) transport in the kidney and intestine. Previous reports suggested a hormonal cAMP-dependent regulation of Mg(2+) reabsorption in the kidney. The molecular details of this process

Zero-reabsorption doped-nanocrystal luminescent solar concentrators.

Science.gov (United States)

Erickson, Christian S; Bradshaw, Liam R; McDowall, Stephen; Gilbertson, John D; Gamelin, Daniel R; Patrick, David L

2014-04-22

Optical concentration can lower the cost of solar energy conversion by reducing photovoltaic cell area and increasing photovoltaic efficiency. Luminescent solar concentrators offer an attractive approach to combined spectral and spatial concentration of both specular and diffuse light without tracking, but they have been plagued by luminophore self-absorption losses when employed on practical size scales. Here, we introduce doped semiconductor nanocrystals as a new class of phosphors for use in luminescent solar concentrators. In proof-of-concept experiments, visibly transparent, ultraviolet-selective luminescent solar concentrators have been prepared using colloidal Mn(2+)-doped ZnSe nanocrystals that show no luminescence reabsorption. Optical quantum efficiencies of 37% are measured, yielding a maximum projected energy concentration of ∼6× and flux gain for a-Si photovoltaics of 15.6 in the large-area limit, for the first time bounded not by luminophore self-absorption but by the transparency of the waveguide itself. Future directions in the use of colloidal doped nanocrystals as robust, processable spectrum-shifting phosphors for luminescent solar concentration on the large scales required for practical application of this technology are discussed.

Renal MR angiography and perfusion in the pig using hyperpolarized water

DEFF Research Database (Denmark)

Lipsø, Hans Kasper Wigh; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling

2016-01-01

at 3 Tesla (T). Approximately 15 mL of hyperpolar-ized water was injected in the renal artery by hand over 4–5 s.Results: A liquid state polarization of 5.3 6 0.9% of 3.8 M pro-tons in 15 mL of deuterium oxide was achieved with a T1of24 6 1 s. This allowed injection through an arterial catheterinto...

The cytochrome P-450 inhibitor cobalt chloride prevents inhibition of renal Na,K-ATPase and redistribution of apical NHE-3 during acute hypertension

DEFF Research Database (Denmark)

Zhang, Y B; Magyar, C E; Holstein-Rathlou, N H

1998-01-01

by cobalt chloride (CoCl2). Four groups of rats (n = 4 to 5) were studied: (1) sham-operated; (2) 50 mg of CoCl2/kg subcutaneously for 2 d; (3) acute hypertension by constricting arteries for 5 min; and (4) acute hypertension after CoCl2 treatment as in group 3. Renal cortex was analyzed after sorbitol...... reabsorption and diuresis and abolishes Na,K-ATPase inhibition and NHE-3 redistribution during acute hypertension, evidence that these responses may be mediated by cytochrome P-450 arachidonate metabolites....

Significant impact of transient deterioration of renal function on dosimetry in PRRT

International Nuclear Information System (INIS)

Van Binnebeek, S.; Baete, K.; Terwinghe, C.

2013-01-01

Peptide receptor radionuclide therapy (PRRT), with 90 Y-DOTATOC and 177 Lu-DOTATATE as most clinically used radiopeptides, is widely used in the management of metastatic neuroendocrine tumors. With respect to radiation dosimetry, the kidneys are the critical organ for 90 Y-DOTATOC. Renal irradiation is significant because of reabsorption of the radiopeptide from the proximal tubuli and the resulting retention in the interstitium, mainly in the inner cortical zone. The high energy and consequently wide range in tissue of the yttrium-90 beta particle result in high absorbed doses to the kidney cortex and medulla. Accurate renal dosimetry can help minimizing radiation nephropathy. We report a case of a 69-year-old candidate for PRRT with an acceptable kidney function at the time of screening. When performing 111 In-octreotide pretreatment dosimetry 3 weeks later, we observed a drastic deterioration in kidney function, caused by undisclosed non-steroidal anti-inflammatory drug intake. The calculated kidney biological effective dose (BED) was 153 Gy after four projected cycles. PRRT was canceled as our full-course BED limit is 37 Gy and the patient was switched to morphine analgesics. Renal function normalized after 3 months and repeated dosimetry yielded an acceptable kidney BED of 28 Gy after four projected cycles (7 Gy/cycle). This case emphasizes that acute kidney insufficiency can yield toxic kidney doses in a single therapy cycle, with an inherent risk of persistent renal insufficiency. All clinical factors which might influence kidney function should be verified at screening and before PRRT administration. (author)

Approaching to DM2 through sodium-glucose cotransporter-2: does it make sense?

Science.gov (United States)

Segura, Julián

2016-11-01

The kidney is involved in glucose homeostasis through three main mechanisms: renal gluconeogenesis, renal glucose consumption and glucose reabsorption in the proximal tubule. Glucose reabsorption is one of the most relevant physiological functions of the kidney, through which filtered glucose is fully recovered, urine is free of glucose, and calorie loss is prevented. Approximately 90% of the glucose is reabsorbed in the S1 segment of the proximal tubule, where GLUT2 and SGLT2 transporters are located, while the remaining 10% is reabsorbed in the S3 segment by SGLT1 and GLUT1 transporters. In patients with hyperglycaemia, the kidney continues reabsorbing glucose, and hyperglycaemia is maintained. Most renal glucose reabsorption is mediated by the SGLT2 transporter. Several experimental and clinical studies suggest that pharmacological blockade of this transporter might be beneficial in the management of hyperglycemia in patients with type 2 diabetes. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

[Contribution of the kidney to glucose homeostasis].

Science.gov (United States)

Segura, Julián; Ruilope, Luis Miguel

2013-09-01

The kidney is involved in glucose homeostasis through three major mechanisms: renal gluconeogenesis, renal glucose consumption, and glucose reabsorption in the proximal tubule. Glucose reabsorption is one of the most important physiological functions of the kidney, allowing full recovery of filtered glucose, elimination of glucose from the urine, and prevention of calorie loss. Approximately 90% of the glucose is reabsorbed in the S1 segment of the proximal tubule, where glucose transporter-2 (GLUT2) and sodium-glucose transporter-2 (SGLT2) are located, while the remaining 10% is reabsorbed in the S3 segment by SGLT1 and GLUT1 transporters. In patients with hyperglycemia, the kidney continues to reabsorb glucose, thus maintaining hyperglycemia. Most of the renal glucose reabsorption is mediated by SGLT2. Several experimental and clinical studies suggest that pharmacological blockade of this transporter might be beneficial in the management of hyperglycemia in patients with type 2 diabetes. Copyright © 2013 Elsevier España, S.L. All rights reserved.

TRPV5: an ingeniously controlled calcium channel.

NARCIS (Netherlands)

Groot, T. de; Bindels, R.J.M.; Hoenderop, J.G.J.

2008-01-01

Body Ca(2+) homeostasis is tightly controlled and slight disturbances in renal Ca(2+) reabsorption can lead to excessive urine Ca(2+) excretion and promote kidney stone formation. The epithelial Ca(2+) channel TRPV5 constitutes the rate-limiting step of active Ca(2+) reabsorption in the kidney.

Successful Management of Repetitive Urinary Obstruction and Anuria Caused by Double J Stent Calculi Formation after Renal Transplantation

Directory of Open Access Journals (Sweden)

Zongyao Hao

2014-01-01

Full Text Available This report firstly describes an extremely rare case of repetitive double J stent calculi formation after renal transplantation caused by the antihyperparathyroidism (HPT drug calcitriol. In 2012, a woman initially presented to our hospital for anuria with lower abdominal pain. She was diagnosed with allograft hydronephrosis and double J stents obstruction by calculi formation after transplantation and treated with triplicate stents replacements in another hospital without clinical manifestations improvements. Through detailed exploration of medical history, we conclude that the abnormal calculi formation is due to the calcitriol (1,25-dihydroxyvitamin D3 administration, a drug which can increase renal tubular reabsorption of calcium for treating posttransplant HPT bone disease. After discontinuing calcitriol, the patient was stone-free and had a good recovery without severe complications during the 9-month follow-up. Our novel findings may provide an important clue and approach to managing formidable repetitive double J stent calculi formation in the clinical trial.

A novel member of the trehalose transporter family functions as an H+-dependent trehalose transporter in the reabsorption of trehalose in Malpighian tubules.

Directory of Open Access Journals (Sweden)

Shingo eKikuta

2012-07-01

Full Text Available In insects, Malpighian tubules are functionally analogous to mammalian kidneys in that they not only are essential to excrete waste molecules into the lumen but also are responsible for the reabsorption of indispensable molecules, such as sugars, from the lumen to the principal cells. Among sugars, the disaccharide trehalose is highly important to insects because it is the main hemolymph sugar to serve as a source of energy and carbon. The trehalose transporter TRET1 participates in the transfer of newly synthesized trehalose from the fat body across the cellular membrane into the hemolymph. Although transport proteins must play a pivotal role in the reabsorption of trehalose in Malpighian tubules, the molecular context underlying this process remains obscure. Previously, we identified a Tret1 homolog (Nlst8 that is expressed principally in the Malpighian tubules of the brown planthopper (BPH. Here, we used the Xenopus oocyte expression system to show that NlST8 exerts trehalose transport activity that is elevated under low pH conditions. These functional assays indicate that Nlst8 encodes a proton-dependent trehalose transporter (H-TRET1. To examine the involvement of Nlst8 in trehalose reabsorption, we analyzed the sugar composition of honeydew by using BPH with RNAi gene silencing. Trehalose was detected in the honeydew as waste excreted from Nlst8-dsRNA-injected BPH under hyperglycemic conditions. However, trehalose was not expelled from GFP-dsRNA-injected BPH even under hyperglycemic conditions. We conclude that NlST8 could participate in trehalose reabsorption driven by a H+ gradient from the lumen to the principal cells of the Malpighian tubules.

Evaluation of renal oxygenation level changes after water loading using susceptibility-weighted imaging and T2{sup *} mapping

Energy Technology Data Exchange (ETDEWEB)

Ding, Jiule; Xing, Wei; Chen, Jie; Pan, Liang; Sun, Jun; Xing, Shi Jun [Dept. of Radiology, Third Affiliated Hospital of Suzhou University, Changzhou (China); Wu, Dong Mei [Shanghai Key Laboratory of Magnetic Resonance Imaging, East China Normal University, Shanghai (China); Dai, Yong Ming [Philips Healthcare, Shanghai (China)

2015-08-15

To assess the feasibility of susceptibility-weighted imaging (SWI) while monitoring changes in renal oxygenation level after water loading. Thirty-two volunteers (age, 28.0 ± 2.2 years) were enrolled in this study. SWI and multi-echo gradient echo sequence-based T2{sup *} mapping were used to cover the kidney before and after water loading. Cortical and medullary parameters were measured using small regions of interest, and their relative changes due to water loading were calculated based on baseline and post-water loading data. An intraclass correlation coefficient analysis was used to assess inter-observer reliability of each parameter. A receiver operating characteristic curve analysis was conducted to compare the performance of the two methods for detecting renal oxygenation changes due to water loading. Both medullary phase and medullary T2{sup *} values increased after water loading (p < 0.001), although poor correlations were found between the phase changes and the T2{sup *} changes (p > 0.05). Interobserver reliability was excellent for the T2{sup *} values, good for SWI cortical phase values, and moderate for the SWI medullary phase values. The area under receiver operating characteristic curve of the SWI medullary phase values was 0.85 and was not different from the medullary T2{sup *} value (0.84). Susceptibility-weighted imaging enabled monitoring changes in the oxygenation level in the medulla after water loading, and may allow comparable feasibility to detect renal oxygenation level changes due to water loading compared with that of T2{sup *} mapping.

Controlling reabsorption effect of bi-color CdSe quantum dots-based white light-emitting diodes

Science.gov (United States)

Siao, Cyuan-Bin; Chung, Shu-Ru; Wang, Kuan-Wen

2017-08-01

The colloidal semiconductor quantum dots (QDs) have the potentials to be used in white light-emitting diode (WLED) as a down-converting component to replace incandescent lamps, because the traditional WLED composed of Y3Al5O12:Ce3+ (YAG:Ce) phosphor lack of red color emissions and shows low color quality. Among various QDs, CdSe has been extensively studied because it possesses attractive characteristics such as high quantum yields (QYs), narrow emission spectral bandwidth, as well as size-tunable optical characteristics. However, in order to enhance the color rendering index (CRI) of WLED, blending materials with different emission wavelengths has been used frequently. Unfortunately, these procedures are complex and time-consuming, and the emission energy of smaller QDs can be reabsorbed by larger QDs, resulting in decreasing the excitation intensity in yellowish-green region. Therefore, in this study, in order to decrease the reabsorption effect and to simplify the procedures, we have demonstrated a facile thermal pyrolyzed route to prepare bicolor CdSe QDs with dual-wavelengths. The emission wavelengths, particle sizes, and QYs of QDs can be tuned from 537/595 to 537/602 nm, 2.59/3.92 to 2.59/4.01 nm, and 27 to 40 %, for GR1 to 3 samples, respectively when the amount of Se precursor is decreased from 1.5 to 0.75 mmol. Meanwhile, the area ratio of green to red (Ag/Ar) in fluorescence spectra is gradually increased, due to the increase in growth rate, and decrease in nuclei formation in red emission. The GR1, GR2, and GR3 QDs are then encapsulated by convert types to form the LED, in which the QDs are deposited on the blue-emitting InGaN LED chip (λem = 450 nm). After encapsulation, the devices properties of Commission International d'Eclairage (CIE) chromaticity and Ag/Ar area ratio are (0.40, 0.24), 0.28/1, (0.40, 0.31), 0.52/1, and (0.40, 0.38), 1.02/1, respectively for GR1, GR2, and GR3. The results show that the green emission intensity are strongly

Cyclophilin B expression in renal proximal tubules of hypertensive rats.

Science.gov (United States)

Kainer, D B; Doris, P A

2000-04-01

Rat cyclophilin-like protein (Cy-LP) is a candidate hypertension gene initially identified by differential hybridization and implicated in renal mechanisms of salt retention and high blood pressure. We report the molecular characterization of rat cyclophilin B (CypB) and demonstrate, through sequence analysis and an allele-specific polymerase chain reaction primer assay, that CypB but not Cy-LP is expressed in rat kidney. CypB is an endoplasmic reticulum-localized prolyl-isomerase that interacts with elongation initiation factor 2-beta, an important regulator of protein translation and a central component of the endoplasmic reticulum stress response to hypoxia or ATP depletion. Active renal transport of sodium is increased in the spontaneously hypertensive rat (SHR), and there is evidence that this coincides with hypoxia and ATP depletion in the renal cortex. In the present studies we have examined expression of CypB in rat proximal tubules, which contributes to the increased renal sodium reabsorption in this model of hypertension. We report that CypB transcript abundance is significantly elevated in proximal convoluted tubules from SHR compared with the control Wistar-Kyoto strain. This upregulation occurs in weanling animals and precedes the development of hypertension, indicating that it is not a simple response to hypertension in SHR. Further, CypB expression is also higher in a proximal tubule cell line derived from SHR compared with a similar line derived from Wistar-Kyoto rats, indicating that this difference is genetically determined. No sequence differences were observed in the CypB cDNA from these 2 strains. These observations suggest that a genetically determined alteration in proximal tubules from SHR occurs that leads to increased expression of CypB. In view of evidence linking CypB to the regulation of elongation initiation factor-2, the upregulation of CypB may result from metabolic stress.

Congenital nephrogenic diabetes insipidus: the current state of affairs.

Science.gov (United States)

Wesche, Daniel; Deen, Peter M T; Knoers, Nine V A M

2012-12-01

The anti-diuretic hormone arginine vasopressin (AVP) is released from the pituitary upon hypovolemia or hypernatremia, and regulates water reabsorption in the renal collecting duct principal cells. Binding of AVP to the arginine vasopressin receptor type 2 (AVPR2) in the basolateral membrane leads to translocation of aquaporin 2 (AQP2) water channels to the apical membrane of the collecting duct principal cells, inducing water permeability of the membrane. This results in water reabsorption from the pro-urine into the medullary interstitium following an osmotic gradient. Congenital nephrogenic diabetes insipidus (NDI) is a disorder associated with mutations in either the AVPR2 or AQP2 gene, causing the inability of patients to concentrate their pro-urine, which leads to a high risk of dehydration. This review focuses on the current knowledge regarding the cell biological aspects of congenital X-linked, autosomal-recessive and autosomal-dominant NDI while specifically addressing the latest developments in the field. Based on deepened mechanistic understanding, new therapeutic strategies are currently being explored, which we also discuss here.

Reversal of Proximal Renal Tubular Dysfunction after Nucleotide Analogue Withdrawal in Chronic Hepatitis B

Directory of Open Access Journals (Sweden)

Abhasnee Sobhonslidsuk

2017-01-01

Full Text Available Aims. Proximal renal tubular dysfunction (PRTD is an infrequent complication after nucleotide analogue therapy. We evaluated the outcomes of PRTD and nephrotoxicity after nucleotide analogue withdrawal in chronic hepatitis B (CHB. Methods. A longitudinal follow-up study was performed in patients with PRTD after nucleotide analogue discontinuation. Serum and urine were collected at baseline and every 3 months for one year. The fractional excretion of phosphate (PO4, uric acid (UA, and potassium and tubular maximal reabsorption rate of PO4 to glomerular filtration rate (TmPO4/GFR were calculated. Renal losses were defined based on the criteria of substance losses. Subclinical PRTD and overt PRTD were diagnosed when 2 and ≥3 criteria were identified. Results. Eight subclinical and eight overt PRTD patients were enrolled. After nucleotide analogue withdrawal, there were overall improvements in GFR, serum PO4, and UA. Renal loss of PO4, UA, protein, and β2-microglobulin reduced over time. At one year, complete reversal of PRTD was seen in 13 patients (81.2%. Improvements in PRTD were seen in all but one patient. Conclusion. One year after nucleotide analogue withdrawal, PRTD was resolved in most patients. Changes in TmPO4/GFR, urinary protein, and β2-microglobulin indicate that urinary biomarkers may represent an early sign of PRTD recovery.

The renal handling of sodium and water is not affected by the standard-dose cisplatin treatment for testicular cancer

DEFF Research Database (Denmark)

Daugaard, G; Strandgaard, S; Holstein-Rathlou, N H

1987-01-01

Renal clearances of 51Cr-EDTA, lithium, sodium and potassium were measured before and after each of four consecutive treatment series with cisplatin in 15 men with testicular cancer. Since lithium is reabsorbed like sodium and water in the proximal tubules, but not reabsorbed to any measurable...... and all other parameters of glomerular filtration and renal sodium handling remained normal throughout the study (with the exception of a fall in fractional sodium excretion after the first treatment series). Plasma magnesium declined during all four treatment periods, signifying renal magnesium wasting....

Effect of diuretics on renal tubular transport of calcium and magnesium.

Science.gov (United States)

Alexander, R Todd; Dimke, Henrik

2017-06-01

Calcium (Ca 2+ ) and Magnesium (Mg 2+ ) reabsorption along the renal tubule is dependent on distinct trans- and paracellular pathways. Our understanding of the molecular machinery involved is increasing. Ca 2+ and Mg 2+ reclamation in kidney is dependent on a diverse array of proteins, which are important for both forming divalent cation-permeable pores and channels, but also for generating the necessary driving forces for Ca 2+ and Mg 2+ transport. Alterations in these molecular constituents can have profound effects on tubular Ca 2+ and Mg 2+ handling. Diuretics are used to treat a large range of clinical conditions, but most commonly for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate sodium (Na + ) transport, but also indirectly affect renal Ca 2+ and Mg 2+ handling, i.e., by establishing a prerequisite electrochemical gradient. It is therefore not surprising that substantial alterations in divalent cation handling can be observed following diuretic treatment. The effects of diuretics on renal Ca 2+ and Mg 2+ handling are reviewed in the context of the present understanding of basal molecular mechanisms of Ca 2+ and Mg 2+ transport. Acetazolamide, osmotic diuretics, Na + /H + exchanger (NHE3) inhibitors, and antidiabetic Na + /glucose cotransporter type 2 (SGLT) blocking compounds, target the proximal tubule, where paracellular Ca 2+ transport predominates. Loop diuretics and renal outer medullary K + (ROMK) inhibitors block thick ascending limb transport, a segment with significant paracellular Ca 2+ and Mg 2+ transport. Thiazides target the distal convoluted tubule; however, their effect on divalent cation transport is not limited to that segment. Finally, potassium-sparing diuretics, which inhibit electrogenic Na + transport at distal sites, can also affect divalent cation transport. Copyright © 2017 the American Physiological Society.

Genetics of Diabetes Insipidus.

Science.gov (United States)

Schernthaner-Reiter, Marie Helene; Stratakis, Constantine A; Luger, Anton

2017-06-01

Diabetes insipidus is a disease characterized by polyuria and polydipsia due to inadequate release of arginine vasopressin from the posterior pituitary gland (neurohypophyseal diabetes insipidus) or due to arginine vasopressin insensitivity by the renal distal tubule, leading to a deficiency in tubular water reabsorption (nephrogenic diabetes insipidus). This article reviews the genetics of diabetes insipidus in the context of its diagnosis, clinical presentation, and therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Thiazolidinediones and Edema: Recent Advances in the Pathogenesis of Thiazolidinediones-Induced Renal Sodium Retention.

Science.gov (United States)

Horita, Shoko; Nakamura, Motonobu; Satoh, Nobuhiko; Suzuki, Masashi; Seki, George

2015-01-01

Thiazolidinediones (TZDs) are one of the major classes of antidiabetic drugs that are used widely. TZDs improve insulin resistance by activating peroxisome proliferator-activated receptor gamma (PPARγ) and ameliorate diabetic and other nephropathies, at least, in experimental animals. However, TZDs have side effects, such as edema, congestive heart failure, and bone fracture, and may increase bladder cancer risk. Edema and heart failure, which both probably originate from renal sodium retention, are of great importance because these side effects make it difficult to continue the use of TZDs. However, the pathogenesis of edema remains a matter of controversy. Initially, upregulation of the epithelial sodium channel (ENaC) in the collecting ducts by TZDs was thought to be the primary cause of edema. However, the results of other studies do not support this view. Recent data suggest the involvement of transporters in the proximal tubule, such as sodium-bicarbonate cotransporter and sodium-proton exchanger. Other studies have suggested that sodium-potassium-chloride cotransporter 2 in the thick ascending limb of Henle and aquaporins are also possible targets for TZDs. This paper will discuss the recent advances in the pathogenesis of TZD-induced sodium reabsorption in the renal tubules and edema.

THE FAILURE OF CHLOROFORM ADMINISTERED IN THE DRINKING WATER TO INDUCE RENAL TUBULAR CELL NEOPLASIA IN MALE F344/N RATS

Science.gov (United States)

The failure of chloroform administered in drinking water to induce renal tubular cell neoplasia in male F344/N rats Chloroform (TCM) has been demonstrated to be a renal carcinogen in the male Osborne-Mendel rat when administered either by corn oil gavage or in drin...

alpha-Adducin mutations increase Na/K pump activity in renal cells by affecting constitutive endocytosis: implications for tubular Na reabsorption.

Science.gov (United States)

Torielli, Lucia; Tivodar, Simona; Montella, Rosa Chiara; Iacone, Roberto; Padoani, Gloria; Tarsini, Paolo; Russo, Ornella; Sarnataro, Daniela; Strazzullo, Pasquale; Ferrari, Patrizia; Bianchi, Giuseppe; Zurzolo, Chiara

2008-08-01

Genetic variation in alpha-adducin cytoskeletal protein is implicated in the polymerization and bundling of actin and alteration of the Na/K pump, resulting in abnormal renal sodium transport and hypertension in Milan hypertensive rats and humans. To investigate the molecular involvement of alpha-adducin in controlling Na/K pump activity, wild-type or mutated rat and human alpha-adducin forms were, respectively, transfected into several renal cell lines. Through multiple experimental approaches (microscopy, enzymatic assays, coimmunoprecipitation), we showed that rat and human mutated forms increased Na/K pump activity and the number of pump units; moreover, both variants coimmunoprecipitate with Na/K pump. The increased Na/K pump activity was not due to changes in its basolateral localization, but to an alteration of Na/K pump residential time on the plasma membrane. Indeed, both rat and human mutated variants reduced constitutive Na/K pump endocytosis and similarly affected transferrin receptor trafficking and fluid-phase endocytosis. In fact, alpha-adducin was detected in clathrin-coated vesicles and coimmunoprecipitated with clathrin. These results indicate that adducin, besides its modulatory effects on actin cytoskeleton dynamics, might play a direct role in clathrin-dependent endocytosis. The constitutive reduction of the Na/K pump endocytic rate induced by mutated adducin variants may be relevant in Na-dependent hypertension.

Renal Function in Hypothyroidism

International Nuclear Information System (INIS)

Khalid, S.; Khalid, M; Elfaki, M.; Hassan, N.; Suliman, S.M.

2007-01-01

Background Hypothyroidism induces significant changes in the function of organ systems such as the heart, muscles and brain. Renal function is also influenced by thyroid status. Physiological effects include changes in water and electrolyte metabolism, notably hyponatremia, and reliable alterations of renal hemodynamics, including decrements in renal blood flow, renal plasma flow, glomerular filtration rate (GFR). Objective Renal function is profoundly influenced by thyroid status; the purpose of the present study was to determine the relationship between renal function and thyroid status of patients with hypothyroidism. Design and Patients In 5 patients with primary hypothyroidism and control group renal functions are measured by serum creatinine and glomerular filtration rate (GFR) using modified in diet renal disease (MDRD) formula. Result In hypothyroidism, mean serum creatinine increased and mean estimated GFR decreased, compared to the control group mean serum creatinine decreased and mean estimated GFR Increased. The hypothyroid patients showed elevated serum creatinine levels (> 1.1mg/dl) compared to control group (p value .000). In patients mean estimated GFR decreased, compared to mean estimated GFR increased in the control group (p value= .002).

A study of nephron function in normal tropical residents using the creatinine and lithium clearances

Science.gov (United States)

Arthur, S. K.; Nyarko, A. K.; Asaku, J. Y.; Akyeampong, A. Y.

The kidney bears the brunt of the demands of a tropical climate for water and electrolyte homeostasis. We hypothesised that a tropical climate may cause adaptive changes in the entire organism leading to altered renal function in our subjects. Hence renal function data for residents of a temperate climate may not be applic- able to tropical residents. We therefore sought to elucidate renal function in subjects residing in a tropical climate. We used lithium clearance, CLi, a non-invasive tool for assessing proximal tubular function in humans, and endogenous creatinine clearance, CCr, to estimate proximal tubular function and glomerular function, respectively, in our subjects. We did this in order to establish whether or not nephron function in our subjects differs from that for residents of a temperate climate. Nineteen male and 12 female Ghanaian subjects aged between 15 and 48 years were studied. The estimated GCr was 117.3+/-6.6 ml/min for male subjects and 97+/-6.4 ml/min for female subjects. CLi was 20.3+/-1.6 ml/min for male and 19.1+/-0.4 ml/min for female subjects, respectively. The estimated absolute reabsorption rate of fluid of proximal tubules was 97.0+/-6.0 ml/min for males and 78.1+/-6.0 ml/min for females. The percentage proximal fluid reabsorption for male and female subjects was 81.2+/-1.4 and 79.5+/-1.6, respectively. The differences between male and female values (mean+/-SEM) were not statistically significant. The data suggest that the proximal tubule in residents of a tropical climate may reabsorb more fluid compared to that in residents of a temperate climate. Our values for proximal tubular reabsorption are higher than those reported for residents of a temperature climate. Our estimate of glomerular filtration, however, is similar to published data for Caucasians. The difference in proximal tubular function may reflect possible renal adaptation to a hot, humid climate. We conclude that renal function of tropical residents differs from that of

The angiotensin type 2 receptor and the kidney

DEFF Research Database (Denmark)

Peluso, Antonio A B; Santos, Robson A S; Unger, Thomas H

2017-01-01

by internalisation of these transporters, thus reducing reabsorption and increasing natriuresis/diuresis. Regarding renal pathology, several studies demonstrated an attenuation of renal injury caused by diabetes or by obesity with or without high-salt diet through anti-inflammatory, antifibrotic, and antioxidative...

Relaxation of atomic state multipoles by radiation re-absorption: Neon 2p2 atoms in a discharge plasma

International Nuclear Information System (INIS)

Nimura, M.; Imagawa, T.; Hasuo, M.; Fujimoto, T.

2005-01-01

In a positive column of a glow discharge in the magnetic field of 36.4G, a linearly polarized laser pulse or a circularly polarized laser pulse has produced polarized neon atoms (alignment or orientation) in the 2p 2 (Paschen notation) level from the 1s 3 level. The subsequent fluorescence to the 1s 2 level was observed with its polarized components resolved. Depopulation, disorientation and disalignment rates of the 2p 2 atom were measured and their discharge current dependences were examined for a discharge current from 0.4 to 2.0mA. The degrees of radiation re-absorption, or the optical thickness, of the transition lines from the 2p 2 level to the 1s 2 -1s 5 levels were measured as functions of the discharge current. A Monte Carlo simulation was performed by which the depopulation, disorientation and disalignment rates by the radiation re-absorption for these transitions were determined. The calculated rates were compared with the observed ones and found to reproduce the their discharge current dependences. D'Yankonov and Perel's analytical expression for these rates was quantified from comparison with the Monte Carlo results

The Piezo Actuator-Driven Pulsed Water Jet System for Minimizing Renal Damage after Off-Clamp Laparoscopic Partial Nephrectomy.

Science.gov (United States)

Kamiyama, Yoshihiro; Yamashita, Shinichi; Nakagawa, Atsuhiro; Fujii, Shinji; Mitsuzuka, Koji; Kaiho, Yasuhiro; Ito, Akihiro; Abe, Takaaki; Tominaga, Teiji; Arai, Yoichi

2017-09-01

In the setting of partial nephrectomy (PN) for renal cell carcinoma, postoperative renal dysfunction might be caused by surgical procedure. The aim of this study was to clarify the technical safety and renal damage after off-clamp laparoscopic PN (LPN) with a piezo actuator-driven pulsed water jet (ADPJ) system. Eight swine underwent off-clamp LPN with this surgical device, while off-clamp open PN was also performed with radio knife or soft coagulation. The length of the removed kidney was 40 mm, and the renal parenchyma was dissected until the renal calyx became clearly visible. The degree of renal degeneration from the resection surface was compared by Hematoxylin-Eosin staining and immunostaining for 1-methyladenosine, a sensitive marker for the ischemic tissue damage. The mRNA levels of neutrophil gelatinase-associated lipocalin (Ngal), a biomarker for acute kidney injury, were measured by quantitative real-time PCR. Off-clamp LPN with ADPJ system was successfully performed while preserving fine blood vessels and the renal calix with little bleeding. In contrast to other devices, the resection surface obtained with the ADPJ system showed only marginal degree of ischemic changes. Indeed, the expression level of Ngal mRNA was lower in the resection surface obtained with the ADPJ system than that with soft coagulation (p = 0.02). Furthermore, using the excised specimens of renal cell carcinoma, we measured the breaking strength at each site of the human kidney, suggesting the applicability of this ADPJ to clinical trials. In conclusion, off-clamp LPN with the ADPJ system could be safely performed with attenuated renal damage.

Fructokinase activity mediates dehydration-induced renal injury.

Science.gov (United States)

Roncal Jimenez, Carlos A; Ishimoto, Takuji; Lanaspa, Miguel A; Rivard, Christopher J; Nakagawa, Takahiko; Ejaz, A Ahsan; Cicerchi, Christina; Inaba, Shinichiro; Le, MyPhuong; Miyazaki, Makoto; Glaser, Jason; Correa-Rotter, Ricardo; González, Marvin A; Aragón, Aurora; Wesseling, Catharina; Sánchez-Lozada, Laura G; Johnson, Richard J

2014-08-01

The epidemic of chronic kidney disease in Nicaragua (Mesoamerican nephropathy) has been linked with recurrent dehydration. Here we tested whether recurrent dehydration may cause renal injury by activation of the polyol pathway, resulting in the generation of endogenous fructose in the kidney that might subsequently induce renal injury via metabolism by fructokinase. Wild-type and fructokinase-deficient mice were subjected to recurrent heat-induced dehydration. One group of each genotype was provided water throughout the day and the other group was hydrated at night, after the dehydration. Both groups received the same total hydration in 24 h. Wild-type mice that received delayed hydration developed renal injury, with elevated serum creatinine, increased urinary NGAL, proximal tubular injury, and renal inflammation and fibrosis. This was associated with activation of the polyol pathway, with increased renal cortical sorbitol and fructose levels. Fructokinase-knockout mice with delayed hydration were protected from renal injury. Thus, recurrent dehydration can induce renal injury via a fructokinase-dependent mechanism, likely from the generation of endogenous fructose via the polyol pathway. Access to sufficient water during the dehydration period can protect mice from developing renal injury. These studies provide a potential mechanism for Mesoamerican nephropathy.

Accounting for oxygen in the renal cortex: a computational study of factors that predispose the cortex to hypoxia.

Science.gov (United States)

Lee, Chang-Joon; Gardiner, Bruce S; Ngo, Jennifer P; Kar, Saptarshi; Evans, Roger G; Smith, David W

2017-08-01

We develop a pseudo-three-dimensional model of oxygen transport for the renal cortex of the rat, incorporating both the axial and radial geometry of the preglomerular circulation and quantitative information regarding the surface areas and transport from the vasculature and renal corpuscles. The computational model was validated by simulating four sets of published experimental studies of renal oxygenation in rats. Under the control conditions, the predicted cortical tissue oxygen tension ([Formula: see text]) or microvascular oxygen tension (µPo 2 ) were within ±1 SE of the mean value observed experimentally. The predicted [Formula: see text] or µPo 2 in response to ischemia-reperfusion injury, acute hemodilution, blockade of nitric oxide synthase, or uncoupling mitochondrial respiration, were within ±2 SE observed experimentally. We performed a sensitivity analysis of the key model parameters to assess their individual or combined impact on the predicted [Formula: see text] and µPo 2 The model parameters analyzed were as follows: 1 ) the major determinants of renal oxygen delivery ([Formula: see text]) (arterial blood Po 2 , hemoglobin concentration, and renal blood flow); 2 ) the major determinants of renal oxygen consumption (V̇o 2 ) [glomerular filtration rate (GFR) and the efficiency of oxygen utilization for sodium reabsorption (β)]; and 3) peritubular capillary surface area (PCSA). Reductions in PCSA by 50% were found to profoundly increase the sensitivity of [Formula: see text] and µPo 2 to the major the determinants of [Formula: see text] and V̇o 2 The increasing likelihood of hypoxia with decreasing PCSA provides a potential explanation for the increased risk of acute kidney injury in some experimental animals and for patients with chronic kidney disease. Copyright © 2017 the American Physiological Society.

No effect of dietary fish oil on renal hemodynamics, tubular function, and renal functional reserve in long-term renal transplant recipients

DEFF Research Database (Denmark)

Hansen, J M; Løkkegaard, H; Høy, Carl-Erik

1995-01-01

Dietary supplementation with fish oil rich in n-3 polyunsaturated fatty acids has been suggested to protect the kidney against cyclosporin A (CsA) toxicity. This study investigated the effects of a 10-wk dietary supplementation with fish oil on renal function and renal functional reserve in healt...... transplant recipients treated with a low maintenance dose of CsA had a well-preserved renal functional reserve, and dietary supplementation with fish oil in these patients did not improve renal function.......Dietary supplementation with fish oil rich in n-3 polyunsaturated fatty acids has been suggested to protect the kidney against cyclosporin A (CsA) toxicity. This study investigated the effects of a 10-wk dietary supplementation with fish oil on renal function and renal functional reserve in healthy...... volunteers (N = 9) and two groups of stable long-term kidney-transplanted patients treated with maintenance low-dose CsA (3.0 +/- 0.6 mg/kg; N = 9) or without CsA (N = 9). After an overnight fast, the subjects were water loaded, and clearance studies were performed, postponing morning medication. GFR...

Radiation inactivation studies of renal brush border water and urea transport

International Nuclear Information System (INIS)

Verkman, A.S.; Dix, J.A.; Seifter, J.L.; Skorecki, K.L.; Jung, C.Y.; Ausiello, D.A.

1985-01-01

Radiation inactivation was used to determine the nature and molecular weight of water and urea transport pathways in brush border membrane vesicles (BBMV) isolated from rabbit renal cortex. BBMV were frozen to -50 degrees C, irradiated with 1.5 MeV electrons, thawed, and assayed for transport or enzyme activity. The freezing process had no effect on enzyme or transport kinetics. BBMV alkaline phosphatase activity gave linear ln(activity) vs. radiation dose plots with a target size of 68 +/- 3 kDa, similar to previously reported values. Water and solute transport were measured using the stopped-flow light-scattering technique. The rates of acetamide and osmotic water transport did not depend on radiation dose (0-7 Mrad), suggesting that transport of these substances does not require a protein carrier. In contrast, urea and thiourea transport gave linear ln(activity) vs. dose curves with a target size of 125-150 kDa; 400 mM urea inhibited thiourea flux by -50% at 0 and 4.7 Mrad, showing that radiation does not affect inhibitor binding to surviving transporters. These studies suggest that BBMV urea transport requires a membrane protein, whereas osmotic water transport does not

Renal Function in Hypothyroidism

International Nuclear Information System (INIS)

Khalid, A. S; Ahmed, M.I; Elfaki, H.M; Hassan, N.; Suliman, S. M.

2006-12-01

Background hypothyroidism induces significant changes in the function of organ systems such as the heart, muscles and brain. Renal function is also influenced by thyroid status. Physiological effects include changes in water and electrolyte metabolism, notably hyponatraemia, and reliable alterations of renal hemodynamics, including decrements in renal blood flow, renal plasma flow, glomerular filtration rate (GFR). Objective renal function is profoundly influenced by thyroid status, the purpose of the present study was to determine the relationship between renal function and thyroid status of patients with hypothyroidism. Design and patients in 5 patients with primary hypothyroidism and control group renal functions are measured by serum creatinine and glomerular filtration rate(GFR) using modified in diet renal disease (MDRD) formula. Result in hypothyroidism, mean serum creatinine increased and mean estimated GFR decreased, compared to the control group mean serum creatinine decreased and mean estimated GFR increased. The hypothyroid patients showed elevated serum creatinine levels(>1.1 mg/d1) compared to control group (p value= 000). In patients mean estimated GFR increased in the control group (p value=.002).Conclusion thus the kidney, in addition to the brain, heart and muscle, is an important target of the action of thyroid hormones.(Author)

Thiazolidinediones and Edema: Recent Advances in the Pathogenesis of Thiazolidinediones-Induced Renal Sodium Retention

Directory of Open Access Journals (Sweden)

Shoko Horita

2015-01-01

Full Text Available Thiazolidinediones (TZDs are one of the major classes of antidiabetic drugs that are used widely. TZDs improve insulin resistance by activating peroxisome proliferator-activated receptor gamma (PPARγ and ameliorate diabetic and other nephropathies, at least, in experimental animals. However, TZDs have side effects, such as edema, congestive heart failure, and bone fracture, and may increase bladder cancer risk. Edema and heart failure, which both probably originate from renal sodium retention, are of great importance because these side effects make it difficult to continue the use of TZDs. However, the pathogenesis of edema remains a matter of controversy. Initially, upregulation of the epithelial sodium channel (ENaC in the collecting ducts by TZDs was thought to be the primary cause of edema. However, the results of other studies do not support this view. Recent data suggest the involvement of transporters in the proximal tubule, such as sodium-bicarbonate cotransporter and sodium-proton exchanger. Other studies have suggested that sodium-potassium-chloride cotransporter 2 in the thick ascending limb of Henle and aquaporins are also possible targets for TZDs. This paper will discuss the recent advances in the pathogenesis of TZD-induced sodium reabsorption in the renal tubules and edema.

Dynamic regulation and dysregulation of the water channel aquaporin-2: a common cause of and promising therapeutic target for water balance disorders.

Science.gov (United States)

Noda, Yumi

2014-08-01

The human body is two-thirds water. The ability of ensuring the proper amount of water inside the body is essential for the survival of mammals. The key event for maintenance of body water balance is water reabsorption in the kidney collecting ducts, which is regulated by aquaporin-2 (AQP2). AQP2 is a channel that is exclusively selective for water molecules and never allows permeation of ions or other small molecules. Under normal conditions, AQP2 is restricted within the cytoplasm of the collecting duct cells. However, when the body is dehydrated and needs to retain water, AQP2 relocates to the apical membrane, allowing water reabsorption from the urinary tubule into the cell. Its impairments result in various water balance disorders including diabetes insipidus, which is a disease characterized by a massive loss of water through the kidney, leading to severe dehydration in the body. Dysregulation of AQP2 is also a common cause of water retention and hyponatremia that exacerbate the prognosis of congestive heart failure and hepatic cirrhosis. Many studies have uncovered the regulation mechanisms of AQP2 at the single-molecule level, the whole-body level, and the clinical level. In clinical practice, urinary AQP2 is a useful marker for body water balance (hydration status). Moreover, AQP2 is now attracting considerable attention as a potential therapeutic target for water balance disorders which commonly occur in many diseases.

Diminished renal urea excretion in the llama at reduced food intake

International Nuclear Information System (INIS)

Engelhardt, W.; Engelhardt, W. von

1976-01-01

At a low protein low-energy diet or during reduced food intake, the glomerular filtration rate and thereby the glomerular filtered urea was reduced by about 30%. During most experiments tubular reabsorption of filtered urea was rather constant (averaging 43%). A high reabsorption of 87% was observed in one llama for several weeks during a straw diet with moderate supplementation of some carbohydrates. (author)

Renal excretion of water in men under hypokinesia and physical exercise with fluid and salt supplementation

Science.gov (United States)

Zorbas, Yan G.; Federenko, Youri F.; Togawa, Mitsui N.

It has been suggested that under hypokinesia (reduced number of steps/day) and intensive physical exercise, the intensification of fluid excretion in men is apparently caused as a result of the inability of the body to retain optimum amounts of water. Thus, to evaluate this hypothesis, studies were performed with the use of fluid and sodium chloride (NaCl) supplements on 12 highly trained physically healthy male volunteers aged 19-24 years under 364 days of hypokinesis (HK) and a set of intensive physical exercises (PE). They were divided into two groups with 6 volunteers per group. The first group of subjects were submitted to HK and took daily fluid and salt supplements in very small doses and the second group of volunteers were subjected to intensive PE and fluid-salt supplements. For the simulation of the hypokinetic effect, both groups of subjects were kept under an average of 4000 steps/day. During the prehypokinetic period of 60 days and under the hypokinetic period of 364 days water consumed and eliminated in urine by the men, water content in blood, plasma volume, rate of glomerular filtration, renal blood flow, osmotic concentration of urine and blood were measured. Under HK, the rate of renal excretion of water increased considerably in both groups. The additional fluid and salt intake failed to normalize water balance adequately under HK and PE. It was concluded that negative water balance evidently resulted not from shortage of water in the diet but from the inability of the body to retain optimum amounts of fluid under HK and a set of intensive PEs.

Update on the renal toxicity of iodinated contrast drugs used in clinical medicine

Directory of Open Access Journals (Sweden)

Andreucci M

2017-05-01

Full Text Available Michele Andreucci,1 Teresa Faga,1 Raffaele Serra,2 Giovambattista De Sarro,3 Ashour Michael1 1Renal Unit, Department of Health Sciences, 2Interuniversity Center of Phlebolymphology (CIFL, International Research and Educational Program in Clinical and Experimental Biotechnology, Department of Medical and Surgical Sciences, 3Pharmacology Unit, Department of Health Sciences, Magna Graecia University, Catanzaro, Italy Abstract: An important side effect of diagnostic contrast drugs is contrast-induced acute kidney injury (CI-AKI; a sudden decrease in renal function occurring 48–72 hours after injection of a contrast drug that cannot be attributed to other causes. Its existence has recently been challenged, because of some retrospective studies in which the incidence of AKI was not different between subjects who received a contrast drug and those who did not, even using propensity score matching to prevent selection bias. For some authors, only patients with estimated glomerular filtration rate <30 mL/min/1.73 m2 are at significant risk of CI-AKI. Most agree that when renal function is normal, there is no CI-AKI risk. Many experimental studies, however, are in favor of the existence of CI-AKI. Contrast drugs have been shown to cause the following changes: renal vasoconstriction, resulting in a rise in intrarenal resistance (decrease in renal blood flow and glomerular filtration rate and medullary hypoxia; epithelial vacuolization and dilatation and necrosis of proximal tubules; potentiation of angiotensin II effects, reducing nitric oxide (NO and causing direct constriction of descending vasa recta, leading to formation of reactive oxygen species in isolated descending vasa recta of rats microperfused with a solution of iodixanol; increasing active sodium reabsorption in the thick ascending limbs of Henle’s loop (increasing O2 demand and consequently medullary hypoxia; direct cytotoxic effects on endothelial and tubular epithelial cells (decrease

Purinergic Signalling in Inflammatory Renal Disease

Directory of Open Access Journals (Sweden)

Nishkantha eArulkumaran

2013-07-01

Full Text Available Extracellular purines have a role in renal physiology and adaption to inflammation. However, inflammatory renal disease may be mediated by extracellular purines, resulting in renal injury. The role of purinergic signalling is dependent on the concentrations of extracellular purines. Low basal levels of purines are important in normal homeostasis and growth. Concentrations of extracellular purines are significantly elevated during inflammation and mediate either an adaptive role or propagate local inflammation. Adenosine signalling mediates alterations in regional renal blood flow by regulation of the renal microcirculation, tubulo-glomerular feedback, and tubular transport of sodium and water. Increased extracellular ATP and renal P2 receptor-mediated inflammation are associated with various renal diseases, including hypertension, diabetic nephropathy, and glomerulonephritis. Experimental data suggests P2 receptor deficiency or receptor antagonism is associated with amelioration of antibody-mediated nephritis, suggesting a pathogenic (rather than adaptive role of purinergic signalling. We discuss the role of extracellular nucleotides in adaptation to ischaemic renal injury and in the pathogenesis of inflammatory renal disease.

Kidney protection during peptide receptor radionuclide therapy with somatostatin analogues

Energy Technology Data Exchange (ETDEWEB)

Rolleman, Edgar J.; Melis, Marleen; Valkema, Roelf; Krenning, Eric P.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, V 220, Rotterdam (Netherlands); Boerman, Otto C. [Radboud University Hospital, Department of Nuclear Medicine, Nijmegen (Netherlands)

2010-05-15

This review focuses on the present status of kidney protection during peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues. This treatment modality for somatostatin receptor-positive tumours is limited by renal reabsorption and retention of radiolabelled peptides resulting in dose-limiting high kidney radiation doses. Radiation nephropathy has been described in several patients. Studies on the mechanism and localization demonstrate that renal uptake of radiolabelled somatostatin analogues largely depends on the megalin/cubulin system in the proximal tubule cells. Thus methods are needed that interfere with this reabsorption pathway to achieve kidney protection. Such methods include coadministration of basic amino acids, the bovine gelatin-containing solution Gelofusine or albumin fragments. Amino acids are already commonly used in the clinical setting during PRRT. Other compounds that interfere with renal reabsorption capacity (maleic acid and colchicine) are not suitable for clinical use because of potential toxicity. The safe limit for the renal radiation dose during PRRT is not exactly known. Dosimetry studies applying the principle of the biological equivalent dose (correcting for the effect of dose fractionation) suggest that a dose of about 37 Gy is the threshold for development of kidney toxicity. This threshold is lower when risk factors for development of renal damage exist: age over 60 years, hypertension, diabetes mellitus and previous chemotherapy. A still experimental pathway for kidney protection is mitigation of radiation effects, possibly achievable by cotreatment with amifostine (Ethylol), a radiation protector, or with blockers of the renin-angiotensin-aldosterone system. Future perspectives on improving kidney protection during PRRT include combinations of agents to reduce renal retention of radiolabelled peptides, eventually together with mitigating medicines. Moreover, new somatostatin analogues with lower

Kidney protection during peptide receptor radionuclide therapy with somatostatin analogues

International Nuclear Information System (INIS)

Rolleman, Edgar J.; Melis, Marleen; Valkema, Roelf; Krenning, Eric P.; Jong, Marion de; Boerman, Otto C.

2010-01-01

This review focuses on the present status of kidney protection during peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues. This treatment modality for somatostatin receptor-positive tumours is limited by renal reabsorption and retention of radiolabelled peptides resulting in dose-limiting high kidney radiation doses. Radiation nephropathy has been described in several patients. Studies on the mechanism and localization demonstrate that renal uptake of radiolabelled somatostatin analogues largely depends on the megalin/cubulin system in the proximal tubule cells. Thus methods are needed that interfere with this reabsorption pathway to achieve kidney protection. Such methods include coadministration of basic amino acids, the bovine gelatin-containing solution Gelofusine or albumin fragments. Amino acids are already commonly used in the clinical setting during PRRT. Other compounds that interfere with renal reabsorption capacity (maleic acid and colchicine) are not suitable for clinical use because of potential toxicity. The safe limit for the renal radiation dose during PRRT is not exactly known. Dosimetry studies applying the principle of the biological equivalent dose (correcting for the effect of dose fractionation) suggest that a dose of about 37 Gy is the threshold for development of kidney toxicity. This threshold is lower when risk factors for development of renal damage exist: age over 60 years, hypertension, diabetes mellitus and previous chemotherapy. A still experimental pathway for kidney protection is mitigation of radiation effects, possibly achievable by cotreatment with amifostine (Ethylol), a radiation protector, or with blockers of the renin-angiotensin-aldosterone system. Future perspectives on improving kidney protection during PRRT include combinations of agents to reduce renal retention of radiolabelled peptides, eventually together with mitigating medicines. Moreover, new somatostatin analogues with lower

Connexins and the kidney

DEFF Research Database (Denmark)

Hanner, Fiona; Sørensen, Charlotte Mehlin; Holstein-Rathlou, Niels-Henrik

2010-01-01

Connexins (Cxs) are widely-expressed proteins that form gap junctions in most organs, including the kidney. In the renal vasculature, Cx37, Cx40, Cx43, and Cx45 are expressed, with predominant expression of Cx40 in the endothelial cells and Cx45 in the vascular smooth muscle cells. In the tubules......, the major function of Cxs in the kidney appears to be intercellular communication, although they may also form hemichannels that allow cellular secretion of large signaling molecules. Renal Cxs facilitate vascular conduction, juxtaglomerular apparatus calcium signaling, and tubular purinergic signaling....... Accordingly, current evidence points to roles for these Cxs in several important regulatory mechanisms in the kidney, including the renin angiotensin system, tubuloglomerular feedback, and salt and water reabsorption. At the systemic level, renal Cxs may help regulate blood pressure and may be involved...

Control of water absorption by purification of graphite

International Nuclear Information System (INIS)

Simpkins, J.E.; Strehlow, R.A.; Mioduszewski, P.K.; Uckan, T.

1988-01-01

It is well known that graphite can absorb large quantities of water, which can represent an abundant source of oxygen impurities in fusion plasmas if the corresponding components are not properly outgassed. We have outgassed various fusion-relevant graphites (e.g., POCO AXF-5Q) for 1.5 h at 1500/degree/C to release absorbed water and have subsequently exposed the samples to air for various periods of time. Re-absorption of water during the air exposure was estimated by measuring the amount of water produced in subsequent outgassing runs. The results show that the amount of water re-absorbed increases by a factor of approximately 10 within 8 h compared to the sample in the outgassed state but with no air exposure. The water content of the 'as received' material is reached after approximately 30 days. Re-absorption of water was significantly reduced by purification of the investigated graphite samples. This purification process, which consists of heating the sample at 2800/degree/C for 30 min in an argon atmosphere, reduces the levels of trace impurities which can be responsible for catalytic surface reactions on the internal surfaces of the graphite. After exposing an outgassed sample to an electron cyclotron heated plasma followed by 1 h air exposure, the amount of water desorbed was observed to increase by a factor of 6. Data will be presented to correlate this effect with trace impurities. 9 refs., 2 figs., 5 tabs

Endogenous versus exogenous lithium clearance for evaluation of dopamine-induced changes in renal tubular function

DEFF Research Database (Denmark)

Olsen, Niels Vidiendal; Fogh-Andersen, N; Strandgaard, S

1996-01-01

1. The present randomized, double-blind cross-over study compared endogenous and exogenous lithium clearance (CLi) for estimation of the effect of dopamine on tubular sodium reabsorption. Twelve normal, salt-repleted male subjects were investigated on three different occasions with either placebo...... or 450 mg or 600 mg of lithium given in random order at 22.00 hours. After an overnight fast, renal clearance studies were performed during a 1 h baseline period and subsequently during the second hour of an infusion of 3 micrograms min-1 kg-1 of dopamine. 2. Baseline values of endogenous CLi.......3-31.0)% (P lithium increased the baseline sodium clearance (CNa), but glomerular filtration rate and urine flow rate remained unchanged. 3. Dopamine increased CNa to similar values on the three study days. CLi increased to 40.9 (35.5-46.5) ml/min (endogenous lithium, P

The influence of diffusion and of reabsorption of radiation on the particle and energy balance of an infinitely long quasi-cylindrical discharge in hydrogen gas

International Nuclear Information System (INIS)

Goedheer, W.J.

1978-09-01

A numerical study of the pressure and temperature profiles of an infinitely long quasi-cylindrical discharge in hydrogen gas is presented. In particular the influence of the diffusion of atoms in the ground state and the reabsorption of Lyman-α and Lyman-β radiation on both the particle balance and the energy balance of the discharge is studied. Because the transport of the charged particles is corrected for toroidal effects in the regime of high collisionality which is present in the discharge, the model is quasi-cylindrical. The results obtained show an increase of the neutral density on the axis and of the ion and electron density near the wall of the discharge, as compared with earlier calculations in which both diffusion and reabsorption of radiation were neglected. The results are in agreement with measurements in the 'Ringboog' experiment. (Auth.)

Supra-Acetabular Brown Tumor due to Primary Hyperparathyroidism Associated with Chronic Renal Failure

Directory of Open Access Journals (Sweden)

Rosaria M. Ruggeri

2010-01-01

Full Text Available A 63-year-old woman presented to the Orthopedic Unit of our hospital complaining of right hip pain of 6 months'duration associated with a worsening limp. Her past medical history included chronic renal insufficiency. Physical examination revealed deep pain in the iliac region and severe restriction of the right hip's articular function in the maximum degrees of range of motion. X-rays and CT scan detected an osteolytic and expansive lesion of the right supra-acetabular region with structural reabsorption of the right iliac wing. 99mTc-MDP whole-body bone scan showed an abnormal uptake in the right iliac region. Bone biopsy revealed an osteolytic lesion with multinucleated giant cells, indicating a brown tumor. Serum intact PTH was elevated (1020 pg/ml; normal values, 12 62 pg/ml, but her serum calcium was normal (total = 9.4 mg/dl, nv 8.5–10.5; ionized = 5.0 mg/dl, nv 4.2–5.4 due to the coexistence of chronic renal failure. 99mTc-MIBI scintigraphy revealed a single focus of sestamibi accumulation in the left retrosternal location, which turned out to be an intrathoracic parathyroid adenoma at surgical exploration. After surgical removal of the parathyroid adenoma, PTH levels decreased to 212 pg/ml. Three months after parathyroidectomy, the imaging studies showed complete recovery of the osteolytic lesion, thus avoiding any orthopedic surgery. This case is noteworthy because (1 primary hyperparathyroidism was not suspected due to the normocalcemia, likely attributable to the coexistence of chronic renal failure; and (2 it was associated with a brown tumor of unusual location (right supra-acetabular region.

Concentrations of Water-Soluble Vitamins in Blood and Urinary Excretion in Patients with Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Hiromi Iwakawa

2016-01-01

Full Text Available We examined the concentrations of water-soluble vitamins in blood and urinary excretion of 22 patients with type 2 diabetes mellitus (type 2DM and 20 healthy control participants. Macronutrient and vitamin intakes of type 2DM subjects were measured using a weighed food record method. Control participants consumed a semipurified diet for eight days. Multiple linear regression models were used to determine whether significant differences existed in vitamin concentrations in blood independent of age, sex, and other confounding factors. Concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors. Renal clearances of vitamins B6, C, niacin, and folate were significantly higher in type 2DM subjects than in controls. In conclusion, concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors; based on the evidence of increased urinary clearance of these vitamins, the lower levels were likely due to impaired reabsorption processes.

Concentrations of Water-Soluble Vitamins in Blood and Urinary Excretion in Patients with Diabetes Mellitus.

Science.gov (United States)

Iwakawa, Hiromi; Nakamura, Yasuyuki; Fukui, Tomiho; Fukuwatari, Tsutomu; Ugi, Satoshi; Maegawa, Hiroshi; Doi, Yukio; Shibata, Katsumi

2016-01-01

We examined the concentrations of water-soluble vitamins in blood and urinary excretion of 22 patients with type 2 diabetes mellitus (type 2DM) and 20 healthy control participants. Macronutrient and vitamin intakes of type 2DM subjects were measured using a weighed food record method. Control participants consumed a semipurified diet for eight days. Multiple linear regression models were used to determine whether significant differences existed in vitamin concentrations in blood independent of age, sex, and other confounding factors. Concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors. Renal clearances of vitamins B6, C, niacin, and folate were significantly higher in type 2DM subjects than in controls. In conclusion, concentrations of vitamins B2, B6, C, niacin, and folate in blood were significantly lower in type 2DM subjects than in controls, independent of confounding factors; based on the evidence of increased urinary clearance of these vitamins, the lower levels were likely due to impaired reabsorption processes.

The renal concentrating mechanism and the clinical consequences of its loss

Science.gov (United States)

Agaba, Emmanuel I.; Rohrscheib, Mark; Tzamaloukas, Antonios H.

2012-01-01

The integrity of the renal concentrating mechanism is maintained by the anatomical and functional arrangements of the renal transport mechanisms for solute (sodium, potassium, urea, etc) and water and by the function of the regulatory hormone for renal concentration, vasopressin. The discovery of aquaporins (water channels) in the cell membranes of the renal tubular epithelial cells has elucidated the mechanisms of renal actions of vasopressin. Loss of the concentrating mechanism results in uncontrolled polyuria with low urine osmolality and, if the patient is unable to consume (appropriately) large volumes of water, hypernatremia with dire neurological consequences. Loss of concentrating mechanism can be the consequence of defective secretion of vasopressin from the posterior pituitary gland (congenital or acquired central diabetes insipidus) or poor response of the target organ to vasopressin (congenital or nephrogenic diabetes insipidus). The differentiation between the three major states producing polyuria with low urine osmolality (central diabetes insipidus, nephrogenic diabetes insipidus and primary polydipsia) is done by a standardized water deprivation test. Proper diagnosis is essential for the management, which differs between these three conditions. PMID:23293407

Krogh’s principle or a multiple fish model approach to phosphate balance: is there a centrally regulated intestinal-skeletal-renal axis?

Directory of Open Access Journals (Sweden)

Pedro Miguel Guerreiro

2015-10-01

Full Text Available Inorganic phosphate (Pi is a crucial ion for vertebrate life. In addition to many physiological roles it is, together with calcium, the major element forming the internal skeleton and Pi balance has been considered a secondary consequence of calciotropic endocrine factors. However, contrary to calcium which can be readily obtained from even Ca-poor environments, Pi is not available in water, and fish can only obtain it via the food. Intestinal absorption drives Pi into the blood stream, but a central part of Pi balance is renal excretion and conservation. Recently, several Pi specific regulatory factors have been brought to light, and we use fish models to investigate their role and the hypothesis of a centrally controlled intestinal-skeletal-renal Pi axis. Using tissues mounted in Ussing chambers under symmetrical and asymmetrical short-circuited conditions we measure unidirectional 33Pi fluxes and test PTHrP, but also STC and FGF23 as regulatory factors, as well as specific drugs to unveil the functional transporting mechanisms. Pi absorption is modified in starved and fed sea bass, an effect dependent on Pi availability in diet, which modifies gene expression of uptake mechanisms. Phosphate secretion across flounder primary renal cell cultures is increased by PTHrP, which reduces the expression of reabsorption mechanisms such as NaPiII and evokes an increase in GFR in cannulated fish, thus resulting in net Pi excretion. A similar effect occurs in the toadfish urinary bladder, which displays moderate Pi transport that is abolished by the drug ouabain and modified by endocrines. Finally we used the shark choroid plexus (CP to show active CSF-to-blood transport with biochemical properties consistent with PiT Na+-dependent transporters. RT-PCR revealed the PiT1/2, but no NaPiII gene expression and we localized PiT2 in CP apical membranes while PiT1 occurred in vascular endothelial cells. Shark CP expresses both PTHrP and its receptor. Could

Angiotensin II clamp prevents the second step in renal apical NHE3 internalization during acute hypertension

DEFF Research Database (Denmark)

Leong, Patrick K K; Yang, Li E; McDonough, Alicia A

2002-01-01

Acute hypertension inhibits proximal tubule (PT) sodium reabsorption. The resultant increase in NaCl delivery to the macula densa suppresses renin release. We tested whether the sustained pressure-induced inhibition of PT sodium reabsorption requires a renin-mediated decrease in ANG II levels. Pl...

Reduction of renal uptake of 111In-DOTA-labeled and A700-labeled RAFT-RGD during integrin αvβ3 targeting using single photon emission computed tomography and optical imaging.

Science.gov (United States)

Briat, Arnaud; Wenk, Christiane H F; Ahmadi, Mitra; Claron, Michael; Boturyn, Didier; Josserand, Véronique; Dumy, Pascal; Fagret, Daniel; Coll, Jean-Luc; Ghezzi, Catherine; Sancey, Lucie; Vuillez, Jean-Philippe

2012-06-01

Integrin α(v)β(3) expression is upregulated during tumor growth and invasion in newly formed endothelial cells in tumor neovasculature and in some tumor cells. A tetrameric RGD-based peptide, regioselectively addressable functionalized template-(cyclo-[RGDfK])4 (RAFT-RGD), specifically targets integrin α(v)β(3) in vitro and in vivo. When labeled with indium-111, the RAFT-RGD is partially reabsorbed and trapped in the kidneys, limiting its use for further internal targeted radiotherapy and imaging investigations. We studied the effect of Gelofusine on RAFT-RGD renal retention in tumor-bearing mice. Mice were imaged using single photon emission computed tomography and optical imaging 1 and 24 h following tracer injection. Distribution of RAFT-RGD was further investigated by tissue removal and direct counting of the tracer. Kidney sections were analyzed by confocal microscopy. Gelofusine significantly induced a >50% reduction of the renal reabsorption of (111)In-DOTA-RAFT-RGD and A700-RAFT-RGD, without affecting tumor uptake. Injection of Gelofusine significantly reduced the renal retention of labeled RAFT-RGD, while increasing the tumor over healthy tissue ratio. These results will lead to the development of future therapeutic approaches. © 2012 Japanese Cancer Association.

Renal Cell Toxicity of Water-Soluble Coal Extracts from the Gulf Coast

Science.gov (United States)

Ojeda, A. S.; Ford, S.; Ihnat, M.; Gallucci, R. M.; Philp, P. R.

2017-12-01

In the Gulf Coast, many rural residents rely on private well water for drinking, cooking, and other domestic needs. A large portion of this region contains lignite coal deposits within shallow aquifers that potentially leach organic matter into the water supply. It is proposed that the organic matter leached from low-rank coal deposits contributes to the development of kidney disease, however, little work has been done to investigate the toxicity of coal extracts. In this study, human kidney cells (HK-2) were exposed to water-soluble extracts of Gulf Coast Coals to assess toxicity. Cell viability was measured by direct counts of total and necrotic cells. A dose-response curve was used to generate IC50 values, and the extracts showed significant toxicity that ranged from 0.5% w/v to 3% w/v IC50. The most toxic extract was from Louisiana where coal-derived organic material has been previously linked to high incidents of renal pelvic cancer (RPC). Although the toxic threshold measured in this study is significantly higher than the concentration of organic matter in the groundwater, typically affected areas may consume contaminated water over a lifetime. It is possible that the cumulative toxic effects of coal-derived material contribute to the development of disease.

Comorbid renal tubular damage and hypoalbuminemia exacerbate cardiac prognosis in patients with chronic heart failure.

Science.gov (United States)

Otaki, Yoichiro; Watanabe, Tetsu; Takahashi, Hiroki; Funayama, Akira; Kinoshita, Daisuke; Yokoyama, Miyuki; Takahashi, Tetsuya; Nishiyama, Satoshi; Arimoto, Takanori; Shishido, Tetsuro; Miyamoto, Takuya; Konta, Tsuneo; Kubota, Isao

2016-02-01

Renal tubular damage (RTD) and hypoalbuminemia are risks for poor prognosis in patients with chronic heart failure (CHF). Renal tubules play a pivotal role in amino acid and albumin reabsorption, which maintain serum albumin levels. The aims of the present study were to (1) examine the association of RTD with hypoalbuminemia, and (2) assess the prognostic importance of comorbid RTD and hypoalbuminemia in patients with CHF. We measured N-acetyl-β-D-glucosamidase (NAG) levels and the urinary β2-microglobulin to creatinine ratio (UBCR) in 456 patients with CHF. RTD was defined as UBCR ≥ 300 μg/g or NAG ≥ 14.2 U/g. There were moderate correlations between RTD markers and serum albumin (NAG, r = -0.428, P < 0.0001; UBCR, r = -0.399, P < 0.0001). Multivariate logistic analysis showed that RTD was significantly related to hypoalbuminemia in patients with CHF. There were 134 cardiac events during a median period of 808 days. The comorbidity of RTD and hypoalbuminemia was increased with advancing New York Heart Association functional class. Multivariate Cox proportional hazard regression analysis showed that the presence of RTD and hypoalbuminemia was associated with cardiac events. The net reclassification index was significantly improved by adding RTD and hypoalbuminemia to the basic risk factors. Comorbid RTD and hypoalbuminemia are frequently observed and increase the risk for extremely poor outcome in patients with CHF.

Cystinuria in a maned wolf.

Science.gov (United States)

Bush, M; Bovee, K C

1978-11-01

A renal calculus composed principally of the amino acid, cystine, was found in an 8-year-old male maned wolf (Chrysocyon brachyurus). Cystine crystals were found in the urine sediment. The renal clearance of 10 amino acids was abnormal, whereas reabsorption of others was normal. The renal clearance of cystine, lysine, ornithine, and arginine exceeded the filtered load. The renal tubular handling of glucose, phosphate, sodium, potassium, and uric acid was identical to that for the clinically normal dog. These findings indicated an isolated renal tubular defect for cystine and other amino acids.

Redesign of negatively charged 111In-DTPA-octreotide derivative to reduce renal radioactivity.

Science.gov (United States)

Oshima, Nobuhiro; Akizawa, Hiromichi; Kawashima, Hidekazu; Zhao, Songji; Zhao, Yan; Nishijima, Ken-Ichi; Kitamura, Yoji; Arano, Yasushi; Kuge, Yuji; Ohkura, Kazue

2017-05-01

Radiolabeled octreotide derivatives have been studied as diagnostic and therapeutic agents for somatostatin receptor-positive tumors. To prevent unnecessary radiation exposure during their clinical application, the present study aimed to develop radiolabeled peptides which could reduce radioactivity levels in the kidney at both early and late post-injection time points by introducing a negative charge with an acidic amino acid such as L-aspartic acid (Asp) at a suitable position in 111 In-DTPA-conjugated octreotide derivatives. Biodistribution of the radioactivity was evaluated in normal mice after administration of a novel radiolabeled peptide by a counting method. The radiolabeled species remaining in the kidney were identified by comparing their HPLC data with those obtained by alternative synthesis. The designed and synthesized radiolabeled peptide 111 In-DTPA-d-Phe -1 -Asp 0 -d-Phe 1 -octreotide exhibited significantly lower renal radioactivity levels than those of the known 111 In-DTPA-d-Phe 1 -octreotide at 3 and 24h post-injection. The radiolabeled species in the kidney at 24h after the injection of new octreotide derivative represented 111 In-DTPA-d-Phe-OH and 111 In-DTPA-d-Phe-Asp-OH as the metabolites. Their radiometabolites and intact 111 In-DTPA-conjugated octreotide derivative were observed in urine within 24h post-injection. The present study provided a new example of an 111 In-DTPA-conjugated octreotide derivative having the characteristics of both reduced renal uptake and shortened residence time of radioactivity in the kidney. It is considered that this kinetic control was achieved by introducing a negative charge on the octreotide derivative thereby suppressing the reabsorption in the renal tubules and affording the radiometabolites with appropriate lipophilicity. Copyright © 2017 Elsevier Inc. All rights reserved.

Redesign of negatively charged 111In-DTPA-octreotide derivative to reduce renal radioactivity

International Nuclear Information System (INIS)

Oshima, Nobuhiro; Akizawa, Hiromichi; Kawashima, Hidekazu; Zhao, Songji; Zhao, Yan; Nishijima, Ken-ichi; Kitamura, Yoji; Arano, Yasushi; Kuge, Yuji; Ohkura, Kazue

2017-01-01

Introduction: Radiolabeled octreotide derivatives have been studied as diagnostic and therapeutic agents for somatostatin receptor-positive tumors. To prevent unnecessary radiation exposure during their clinical application, the present study aimed to develop radiolabeled peptides which could reduce radioactivity levels in the kidney at both early and late post-injection time points by introducing a negative charge with an acidic amino acid such as L-aspartic acid (Asp) at a suitable position in 111 In-DTPA-conjugated octreotide derivatives. Methods: Biodistribution of the radioactivity was evaluated in normal mice after administration of a novel radiolabeled peptide by a counting method. The radiolabeled species remaining in the kidney were identified by comparing their HPLC data with those obtained by alternative synthesis. Results: The designed and synthesized radiolabeled peptide 111 In-DTPA-D-Phe −1 -Asp 0 -D-Phe 1 -octreotide exhibited significantly lower renal radioactivity levels than those of the known 111 In-DTPA-D-Phe 1 -octreotide at 3 and 24 h post-injection. The radiolabeled species in the kidney at 24 h after the injection of new octreotide derivative represented 111 In-DTPA-D-Phe-OH and 111 In-DTPA-D-Phe-Asp-OH as the metabolites. Their radiometabolites and intact 111 In-DTPA-conjugated octreotide derivative were observed in urine within 24 h post-injection. Conclusion: The present study provided a new example of an 111 In-DTPA-conjugated octreotide derivative having the characteristics of both reduced renal uptake and shortened residence time of radioactivity in the kidney. It is considered that this kinetic control was achieved by introducing a negative charge on the octreotide derivative thereby suppressing the reabsorption in the renal tubules and affording the radiometabolites with appropriate lipophilicity.

SGLT2 inhibitors: molecular design and potential differences in effect.

Science.gov (United States)

Isaji, Masayuki

2011-03-01

The physiological and pathological handling of glucose via sodium-glucose cotransporter-2 (SGLT2) in the kidneys has been evolving, and SGLT2 inhibitors have been focused upon as a novel drug for treating diabetes. SGLT2 inhibitors enhance renal glucose excretion by inhibiting renal glucose reabsorption. Consequently, SGLT2 inhibitors reduce plasma glucose insulin independently and improve insulin resistance in diabetes. To date, various SGLT2 inhibitors have been developed and evaluated in clinical studies. The potency and positioning of SGLT2 inhibitors as an antidiabetic drug are dependent on their characteristic profile, which induces selectivity, efficacy, pharmacokinetics, and safety. This profile decides which SGLT2 inhibitors can be expected for application of the theoretical concept of reducing renal glucose reabsorption for the treatment of diabetes. I review the structure and advancing profile of various SGLT2 inhibitors, comparing their similarities and differences, and discuss the expected SGLT2 inhibitors for an emerging category of antidiabetic drugs.

Black water fever associated with acute renal failure among Congolese children in Kinshasa

Directory of Open Access Journals (Sweden)

Joseph M Bodi

2014-01-01

Full Text Available Acute renal failure (ARF is reported in some severe forms of malaria such as black water fever (BWF. It is associated with a high mortality rate and can be managed effectively with adequate renal replacement. A prospective survey of children with dark urine after a malarial infection with Plasmodium falciparum was coupled with a chart review study of patients managed in the past 11 years in the Pediatrics′ Kinshasa University Hospital. Eighty-nine cases of ARF were identified, but data from only 63 patients were available, of whom 44 (69.8% had severe malaria (39 with BWF and 5 with cerebral malaria. The mean age of the patients was 8.2 ± 1.73 years. Of the 39 cases of BWF, an association with quinine ingestion was observed in 32 children (82%. Urea and creatinine levels were elevated in all cases (135.4 ± 88.2 and 3.83 ± 2.81 mg/dL, respectively. Oligo-anuria was observed in 44.4%, severe metabolic acidosis (bicarbonate <15 mEq/L in 61.5% and hyponatremia (<130 mEq/L in 33.3%. Peritoneal dialysis was required in 36 patients, including 20 with BWF. The remaining patients were managed with conservative treatment. Twenty-eight children (44.4%, including 20 on dialysis, fully recovered and 14 died (22.2%, including eight cases of BWF. Our study suggests that ARF is commonly associated with BWF in Congolese children. Elevated urea and creatinine and severe metabolic acidosis were observed more often than other clinical/metabolic disturbances. Severe renal impairment remains a significant complication with a high mortality rate in low-resource settings.

Effects of a K+ channel blocker on glomerular filtration rate and electrolyte excretion in conscious rats.

Science.gov (United States)

Ludens, J H; Clark, M A; Lawson, J A

1995-06-01

Effects of a K+ channel blocker on glomerular filtration rate and electrolyte excretion in conscious rats were observed. Effects of K+ channel modulation on glomerular filtration rate and electrolyte excretion were studied using the adenosine-triphosphate- (ATP)-sensitive K+ channel blocker 4-morpholinecarboximidine-N-1-adamantyl-N'-cyclohexylhydr ochloride (U-37883A) in conscious rats previously equipped with catheters for clearance studies. In saline-loaded rats, i.v. doses of U-37883A of 1.7, 5.0 and 15 mg/kg increased absolute and fractional Na+ excretion dose-dependently without changing K+ excretion. The glomerular filtration rate remained constant during diuresis. In water-loaded (hypotonic dextrose) rats, free-water clearance studies revealed that the ATP-sensitive K+ channel blocker significantly decreased an index of solute reabsorption (free-water clearance adjusted for chloride clearance) in the diluting segment during peak natriuretic activity. In addition, U-37883A significantly decreased the osmolality of renal papillary interstitial fluid, indicative of an effect in the medullary portion of the diluting segment. Together, these findings suggest that ATP-sensitive K+ channels, possibly those located at the apical boarder, play a pivotal role in Na+ reabsorption in the thick ascending limb of the loop of Henle.

The influence of percutaneous nephrolithotomy on human systemic stress response, SIRS and renal function.

Science.gov (United States)

Shen, Pengfei; Wei, Wuran; Yang, Xiaochun; Zeng, Hao; Li, Xiong; Yang, Jie; Wang, Jia; Huang, Jiaoti

2010-10-01

The objective of this study is to investigate the influences of percutaneous nephrolithotomy (PNL) and open surgery nephrolithotomy on the systemic stress response, SIRS and renal function. Forty patients with kidney calculi were enrolled in the study. Twenty cases were randomized to the PNL group and the other twenty cases to the open surgery group. Levels of C-reactive protein (CRP), interleukin-6(IL-6), β(2)-microglobulin (β(2)-MG), respiration rate, heart rate, body temperature and white blood cell counts were examined. CRP and IL-6 were measured in all patients pre-operatively and on post-operative days 1, 3 and 6, respectively. There was significant difference in their pre- and post-operation levels (P PNL group and 12 cases in open surgery group; there was significant difference between the two groups (P 0.05). Urine β(2)-MG levels were also measured. There was significant difference between pre- and the first day post-PNL (P PNL (P > 0.05). There was significant difference between pre- and first and third day post-open surgery (P 0.05). There was significant difference between two groups at the first, third and sixth days (P PNL group and open surgery group to some extent. The degree of stress response of PNL is lower than that of open surgery, proving the advantages of PNL with reference to serum immunology. There were cases in both the groups with SIRS, but the degree of SIRS in PNL group was lesser than the other group. Both the groups have no obvious effect on glomerular filtration function after operation and have effect on renal tubular reabsorption in the early stage after operation; but the recovery of the PNL group is faster than the open surgery group. It is thus shown that PNL is much safer and more feasible and has lesser effect on renal function.

Renal and sympathoadrenal responses in space

DEFF Research Database (Denmark)

Christensen, N J; Drummer, C; Norsk, P

2001-01-01

According to a classic hypothesis, weightlessness should promote the renal excretion rate of sodium and water and lead to a fluid- and electrolyte-depleted state. This hypothesis is based on experiments in which weightlessness has been simulated in humans by head-down bed rest and water immersion...

Residual Renal Function in Children Treated with Chronic Peritoneal Dialysis

Directory of Open Access Journals (Sweden)

Maria Roszkowska-Blaim

2013-01-01

Full Text Available Residual renal function (RRF in patients with end-stage renal disease (ESRD receiving renal replacement therapy is defined as the ability of native kidneys to eliminate water and uremic toxins. Preserved RRF improves survival and quality of life in adult ESRD patients treated with peritoneal dialysis. In children, RRF was shown not only to help preserve adequacy of renal replacement therapy but also to accelerate growth rate, improve nutrition and blood pressure control, reduce the risk of adverse myocardial changes, facilitate treatment of anemia and calcium-phosphorus balance abnormalities, and result in reduced serum and dialysate fluid levels of advanced glycation end-products. Factors contributing to RRF loss in children treated with peritoneal dialysis include the underlying renal disease such as hemolytic-uremic syndrome and hereditary nephropathy, small urine volume, severe proteinuria at the initiation of renal replacement therapy, and hypertension. Several approaches can be suggested to decrease the rate of RRF loss in pediatric patients treated with chronic peritoneal dialysis: potentially nephrotoxic drugs (e.g., aminoglycosides, episodes of hypotension, and uncontrolled hypertension should be avoided, urinary tract infections should be treated promptly, and loop diuretics may be used to increase salt and water excretion.

Renal handling of drugs in renal failure. I: Differential effects of uranyl nitrate- and glycerol-induced acute renal failure on renal excretion of TEAB and PAH in rats

International Nuclear Information System (INIS)

Lin, J.H.; Lin, T.H.

1988-01-01

Two etiologically different models of experimental acute renal failure were induced in rats by administration of either glycerol or uranyl nitrate. Both compounds caused a substantial decrease in the glomerular filtration rate (GFR) and the net tubular secretion of tetraethylammonium bromide (TEAB) and para-aminohippuric acid (PAH). The degree of renal impairment induced by uranyl nitrate and glycerol appeared to be dose related. Deprivation of drinking water 24 hr before the administration of glycerol potentiated the renal damage. In uranyl nitrate-induced renal failure, the decline of the net tubular secretion for TEAB and PAH was not proportional to the decrease in GFR; the secretion process deteriorated faster than the GFR. For example, when 0.5 mg/kg uranyl nitrate was administered, GFR fell to approximately 65% of normal, whereas the net tubular secretion was decreased to 30% of normal. These results suggest that the tubular transport was preferentially affected by uranyl nitrate. In contrast, in glycerol-induced renal failure, the decline of TEAB secretion fell in a parallel fashion with the GFR, suggesting that the glomeruli and the proximal tubules were equally damaged by glycerol. However, in this latter model, the decline of PAH secretion did not parallel the decrease in GFR, contradicting the proposal that glycerol affects equally the glomeruli and the proximal tubules. This discrepancy may be due to the selective competitive inhibition of PAH secretion by the accumulation of naturally occurring organic acids

Non-steroidal anti-inflammatory drugs and renal response to exercise

DEFF Research Database (Denmark)

Olsen, Niels Vidiendal; Jensen, N G; Hansen, J M

1999-01-01

baseline values or exercise-induced decreases in renal plasma flow or glomerular filtration rate. Indomethacin, but not nabumetone, decreased sodium excretion, urine flow rate and free water clearance. The renal response to exercise, however, remained unchanged. In contrast with nabumatone, indomethacin...

Mechanisms of hypertension in renal radiation

International Nuclear Information System (INIS)

Juncos, L.; Cornejo, J.C.; Cejas, H.; Broglia, C.

1990-01-01

This study was undertaken to investigate the role played by renal functional and structural changes in the development of radiation-induced hypertension. Four groups of rats were studied: (1) left kidney radiated, (2) sham procedure, (3) uninephrectomy followed 3 weeks later by radiation of the contralateral kidney, and (4) uninephrectomy followed by sham procedure 3 weeks later. All radiated rats became hypertensive at 12 weeks (p less than 0.05) and had higher protein excretion (p less than 0.05). In the presence of an intact contralateral kidney, radiation causes mild-to-moderate histological abnormalities, and therefore, creatinine clearance and water and sodium handling do not change. Plasma renin activity increased in this group (p less than 0.05). Radiated uninephrectomized rats showed decreased creatinine clearance (p less than 0.05), but renin activity remained unchanged. These rats developed severe histological abnormalities in glomeruli, interstitia, tubuli, and vessels resulting in increased sodium and water output. The average of individual tubular and interstitial scores correlated significantly with both water intake and output but not with sodium excretion. These studies suggest that in the presence of an intact kidney, renin is an important determinant in the development or maintenance of radiation hypertension, whereas in the absence of the contralateral kidney, severe histological changes and renal failure are prominent despite increased water intake and output. The more severe glomerular sclerosis and proteinuria in the latter model could be related to diminished renal mass

The future of hemodialysis membranes.

Science.gov (United States)

Humes, H D; Fissell, W H; Tiranathanagul, K

2006-04-01

Hemodialytic treatment of patients with either acute or chronic renal failure has had a dramatic impact on the mortality rates of these patients. Unfortunately, this membrane-based therapy is still incomplete renal replacement, as the mortality and morbidity of these patients remain unacceptably high. Much progress must be made to improve the biocompatibility of hemodialysis membranes as well as their hydraulic and permselective properties to remove small solutes and 'middle molecules' in compact cartridges. The next directions of development will leverage materials and mechanical engineering technology, including microfluidics and nanofabrication, to further improve the clearance functions of the kidney to replicate glomerular permselectivity while retaining high rates of hydraulic permeability. The extension of membrane technology to biohybrid devices utilizing progenitor/stem cells will be another substantive advance for renal replacement therapy. The ability to not only replace solute and water clearance but also active reabsorptive transport and metabolic activity will add additional benefit to the therapy of patients suffering from renal failure. This area of translational research is rich in creative opportunities to improve the unmet medical needs of patients with either chronic or acute renal failure.

Associations between plasma tenofovir concentration and renal function markers in HIV-infected women

Directory of Open Access Journals (Sweden)

Mwila Mulubwa

2016-07-01

Objective: To investigate the correlation between plasma tenofovir (TFV concentration and certain renal function markers in HIV-infected women on TDF antiretroviral therapy (ART.These markers were also compared to a HIV-uninfected control group. Methods: HIV-infected women (n = 30 on TDF-based ART were matched with 30 controls forage and body mass index. Renal markers analysed were estimated glomerular filtration rate (eGFR, creatinine clearance (CrCl, serum creatinine, albuminuria, glucosuria, serum urea, serum uric acid, urine sodium and maximum tubular reabsorption of phosphate. Baseline eGFR and CrCl data were obtained retrospectively for the HIV-infected women. Plasma TFV was assayed using a validated HPLC-MS/MS method. Step wise regression, Mann–Whitney test, unpaired and paired t-tests were applied in the statistical analyses. Results: TFV concentration was independently associated with albuminuria (adjusted r2 = 0.339; p = 0.001 in HIV-infected women. In the adjusted (weight analysis, eGFR (p = 0.038,CrCl (p = 0.032 and albuminuria (p = 0.048 were significantly higher in HIV-infected compared to the uninfected women, but eGFR was abnormally high in HIV-infected women. Both eGFR (p < 0.001 and CrCl (p = 0.008 increased from baseline to follow-up in HIV-infected women. Conclusion: Plasma TFV concentration was associated with increased albuminuria in HIV infected women in this sub-study. Both eGFR and CrCl were increased in HIV-infected women from baseline. These findings should be confirmed in larger studies, and hyperfiltration in HIV-infected women warrants further investigation.

Kidney protection during peptide receptor radionuclide therapy with somatostatin analogues.

NARCIS (Netherlands)

Rolleman, E.J.; Melis, M.; Valkema, R.; Boerman, O.C.; Krenning, E.P.; Jong, M. de

2010-01-01

This review focuses on the present status of kidney protection during peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues. This treatment modality for somatostatin receptor-positive tumours is limited by renal reabsorption and retention of radiolabelled peptides

sup(99m)Tc-DMSA renal scintigraphy in renal failure due to various renal diseases

Energy Technology Data Exchange (ETDEWEB)

Hosokawa, S; Daijo, K; Okabe, T; Kawamura, J; Hara, A [Kyoto Univ. (Japan). Hospital

1979-08-01

Renal contours in renal failure were studied by means of sup(99m)Tc-dimercaptosuccinic acid (DMSA) renoscintigraphy. Renal cortical images were obtained even in renal failure cases. Causes of renal failure were chronic glomerulonephritis in 7, bilateral renal tuberculosis in 2, chronic pyelonephritis in 3, bilateral renal calculi in 3, diabetic nephropathy in 2, polycystic kidney disease in 2 and stomach cancer in 1.

sup(99m)Tc-DMSA renal scintigraphy in renal failure due to various renal diseases

International Nuclear Information System (INIS)

Hosokawa, Shin-ichi; Daijo, Kazuyuki; Okabe, Tatsushiro; Kawamura, Juichi; Hara, Akira

1979-01-01

Renal contours in renal failure were studied by means of sup(99m)Tc-dimercaptosuccinic acid (DMSA) renoscintigraphy. Renal cortical images were obtained even in renal failure cases. Causes of renal failure were chronic glomerulonephritis in 7, bilateral renal tuberculosis in 2, chronic pyelonephritis in 3, bilateral renal calculi in 3, diabetic nephropathy in 2, polycystic kidney disease in 2 and stomach cancer in 1. (author)

Sensitivity of fibroblast growth factor 23 measurements in tumor-induced osteomalacia.

NARCIS (Netherlands)

Imel, E.A.; Peacock, M.; Pitukcheewanont, P.; Heller, H.J.; Ward, LM; Shulman, D.; Kassem, M.; Rackoff, P.; Zimering, M.; Dalkin, A.; Drobny, E.; Colussi, G.; Shaker, J.L.; Hoogendoorn, E.H.; Hui, S.L.; Econs, M.J.

2006-01-01

CONTEXT: Tumor-induced osteomalacia (TIO) is a paraneoplastic syndrome of hypophosphatemia, decreased renal phosphate reabsorption, normal or low serum 1,25-dihydryxyvitamin-D concentration, myopathy, and osteomalacia. Fibroblast growth factor 23 (FGF23) is a phosphaturic protein overexpressed in

Renal computed angiography. Part I: Renal CT phlebography. Renal veins variants

International Nuclear Information System (INIS)

Al-Amin, M.; Krupev, M.; Hadjidekov, V.; Plachkov, I.

2012-01-01

The changing trend in renal surgery, transplantation and minimal invasive urology implies preprocedure evaluation of renal veins. Development of imaging methods offers new possibilities for venographic visualization. The goal of this study is to present authors experience in visualization of renal veins using 64 MDCT and to evaluate the utility in assessments of their variants. 128 patients (68 females and 60 males, mean age 53,3) with urological complaints underwent 64MDCT examination including CT angiography. Contrast enhancement includes 3-4ml/sec injection flow of 90 ml contrast medium followed by 20 ml saline at the same rate. In 23 out of 128 examined patients some of the common variants of the renal vein is found. 64 MDCT angiography visualize very well renal veins and becomes method of choice in preoperative assessment of renal vein anatomy. (authors)

Water quality of the river yamuna in the Delhi stretch: Key determinants and management issues

Energy Technology Data Exchange (ETDEWEB)

Trisal, Chaman; Tabassum, Tanveera; Kumar, Ritesh [Wetlands International - South Asia, New Delhi (India)

2008-03-15

The assessment of water quality of the River Yamuna in the Delhi stretch was carried out by determining changes in the concentration levels of 19 physico-chemical parameters. It was observed that vegetation plays an important role in acting as a biological sink for mineral nutrients, thereby restoring the water quality. It is proposed that restoration of the inundation pattern of floodplains would greatly help in re-aeration of the overlying water and re-absorption of pollutants through mud/water exchanges. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Analysis of the efficacy of SGLT2 inhibitors using semi-mechanistic model

Science.gov (United States)

Demin, Oleg; Yakovleva, Tatiana; Kolobkov, Dmitry; Demin, Oleg

2014-01-01

The Renal sodium-dependent glucose co-transporter 2 (SGLT2) is one of the most promising targets for the treatment of type 2 diabetes. Two SGLT2 inhibitors, dapagliflozin, and canagliflozin, have already been approved for use in USA and Europe; several additional compounds are also being developed for this purpose. Based on the in vitro IC50 values and plasma concentration of dapagliflozin measured in clinical trials, the marketed dosage of the drug was expected to almost completely inhibit SGLT2 function and reduce glucose reabsorption by 90%. However, the administration of dapagliflozin resulted in only 30–50% inhibition of reabsorption. This study was aimed at investigating the mechanism underlying the discrepancy between the expected and observed levels of glucose reabsorption. To this end, systems pharmacology models were developed to analyze the time profile of dapagliflozin, canagliflozin, ipragliflozin, empagliflozin, and tofogliflozin in the plasma and urine; their filtration and active secretion from the blood to the renal proximal tubules; reverse reabsorption; urinary excretion; and their inhibitory effect on SGLT2. The model shows that concentration levels of tofogliflozin, ipragliflozin, and empagliflozin are higher than levels of other inhibitors following administration of marketed SGLT2 inhibitors at labeled doses and non-marketed SGLT2 inhibitors at maximal doses (approved for phase 2/3 studies). All the compounds exhibited almost 100% inhibition of SGLT2. Based on the results of our model, two explanations for the observed low efficacy of SGLT2 inhibitors were supported: (1) the site of action of SGLT2 inhibitors is not in the lumen of the kidney's proximal tubules, but elsewhere (e.g., the kidneys proximal tubule cells); and (2) there are other transporters that could facilitate glucose reabsorption under the conditions of SGLT2 inhibition (e.g., other transporters of SGLT family). PMID:25352807

Analysis of efficacy of SGLT2 inhibitors using semi-mechanistic model

Directory of Open Access Journals (Sweden)

Oleg eDemin Jr

2014-10-01

Full Text Available Renal sodium-dependent glucose co-transporter 2 (SGLT2 is one of the most promising targets for the treatment of type 2 diabetes. Two SGLT2 inhibitors, dapagliflozin and canagliflozin, have already been approved for use in USA and Europe; several additional compounds are also being developed for this purpose. Based on the in vitro IC50 values and plasma concentration of dapagliflozin measured in clinical trials, the marketed dosage of the drug was expected to almost completely inhibit SGLT2 function and reduce glucose reabsorption by 90%. However, the administration of dapagliflozin resulted in only 30–50% inhibition of reabsorption. This study was aimed at investigating the mechanism underlying the discrepancy between the expected and observed levels of glucose reabsorption. To this end, systems pharmacology models were developed to analyze the time profile of dapagliflozin, canagliflozin, ipragliflozin, empagliflozin, and tofogliflozin in the plasma and urine; their filtration and active secretion from the blood to the renal proximal tubules; reverse reabsorption; urinary excretion; and their inhibitory effect on SGLT2. The model shows that concentration levels of tofogliflozin, ipragliflozin, and empagliflozin are higher than levels of other inhibitors following administration of marketed SGLT2 inhibitors at labeled doses and non-marketed SGLT2 inhibitors at maximal doses (approved for phase 2/3 studies. All the compounds exhibited almost 100% inhibition of SGLT2. Based on the results of our model, two explanations for the observed low efficacy of SGLT2 inhibitors were supported: 1 the site of action of SGLT2 inhibitors is not in the lumen of the kidney’s proximal tubules, but elsewhere (e.g., the kidneys proximal tubule cells; and 2 there are other transporters that could facilitate glucose reabsorption under the conditions of SGLT2 inhibition (e.g., other transporters of SGLT family.

Lipopolysaccharide-induced acute renal failure in conscious rats

DEFF Research Database (Denmark)

Jonassen, Thomas E N; Graebe, Martin; Promeneur, Dominique

2002-01-01

In conscious, chronically instrumented rats we examined 1) renal tubular functional changes involved in lipopolysaccharide (LPS)-induced acute renal failure; 2) the effects of LPS on the expression of selected renal tubular water and sodium transporters; and 3) effects of milrinone......-alpha and lactate, inhibited the LPS-induced tachycardia, and exacerbated the acute LPS-induced fall in GFR. Furthermore, Ro-20-1724-treated rats were unable to maintain MAP. We conclude 1) PDE3 or PDE4 inhibition exacerbates LPS-induced renal failure in conscious rats; and 2) LPS treated rats develop an escape......, a phosphodiesterase type 3 (PDE3) inhibitor, and Ro-20-1724, a PDE4 inhibitor, on LPS-induced changes in renal function. Intravenous infusion of LPS (4 mg/kg b.wt. over 1 h) caused an immediate decrease in glomerular filtration rate (GFR) and proximal tubular outflow without changes in mean arterial pressure (MAP...

Sensitivity of fibroblast growth factor 23 measurements in tumor-induced osteomalacia

DEFF Research Database (Denmark)

Imel, Erik A; Peacock, Munro; Pitukcheewanont, Pisit

2006-01-01

Tumor-induced osteomalacia (TIO) is a paraneoplastic syndrome of hypophosphatemia, decreased renal phosphate reabsorption, normal or low serum 1,25-dihydryxyvitamin-D concentration, myopathy, and osteomalacia. Fibroblast growth factor 23 (FGF23) is a phosphaturic protein overexpressed in tumors t...

Regulation of extracellular fluid volume and renal function

DEFF Research Database (Denmark)

Henriksen, Jens Henrik Sahl

2011-01-01

Normal fluid homoeostasis includes dynamic shifts in water, crystalloids, and proteins between the various compartments of the body (1–3). The fluid dynamics are controlled by refined mechanisms that include water and solute intake, renal handling, haemodynamic/oncotic forces, and neurohumoral...

Characterization of Organic Anion Transporter 2 (SLC22A7): A Highly Efficient Transporter for Creatinine and Species-Dependent Renal Tubular Expression.

Science.gov (United States)

Shen, Hong; Liu, Tongtong; Morse, Bridget L; Zhao, Yue; Zhang, Yueping; Qiu, Xi; Chen, Cliff; Lewin, Anne C; Wang, Xi-Tao; Liu, Guowen; Christopher, Lisa J; Marathe, Punit; Lai, Yurong

2015-07-01

The contribution of organic anion transporter OAT2 (SLC22A7) to the renal tubular secretion of creatinine and its exact localization in the kidney are reportedly controversial. In the present investigation, the transport of creatinine was assessed in human embryonic kidney (HEK) cells that stably expressed human OAT2 (OAT2-HEK) and isolated human renal proximal tubule cells (HRPTCs). The tubular localization of OAT2 in human, monkey, and rat kidney was characterized. The overexpression of OAT2 significantly enhanced the uptake of creatinine in OAT2-HEK cells. Under physiologic conditions (creatinine concentrations of 41.2 and 123.5 µM), the initial rate of OAT2-mediated creatinine transport was approximately 11-, 80-, and 80-fold higher than OCT2, multidrug and toxin extrusion protein (MATE)1, and MATE2K, respectively, resulting in approximately 37-, 1850-, and 80-fold increase of the intrinsic transport clearance when normalized to the transporter protein concentrations. Creatinine intracellular uptake and transcellular transport in HRPTCs were decreased in the presence of 50 µM bromosulfophthalein and 100 µM indomethacin, which inhibited OAT2 more potently than other known creatinine transporters, OCT2 and multidrug and toxin extrusion proteins MATE1 and MATE2K (IC50: 1.3 µM vs. > 100 µM and 2.1 µM vs. > 200 µM for bromosulfophthalein and indomethacin, respectively) Immunohistochemistry analysis showed that OAT2 protein was localized to both basolateral and apical membranes of human and cynomolgus monkey renal proximal tubules, but appeared only on the apical membrane of rat proximal tubules. Collectively, the findings revealed the important role of OAT2 in renal secretion and possible reabsorption of creatinine and suggested a molecular basis for potential species difference in the transporter handling of creatinine. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Effects of alpha-2 agonists on renal function in hypertensive humans.

Science.gov (United States)

Goldberg, M; Gehr, M

1985-01-01

Centrally acting adrenergic agonists, by decreasing peripheral adrenergic activity, are effective antihypertensive agents. The older agents, however, especially methyldopa, have been associated with weight gain, clinical edema, and antihypertensive tolerance when used as monotherapy. While acute studies in humans have demonstrated weight gain and sodium retention with clonidine and guanabenz, chronic administration results in a decrease in weight and plasma volume. The absence of chronic weight gain and of sodium retention could be the result of a counterbalance between hypotension-related antinatriuresis, secondary to a decrease in glomerular filtration rate and renal blood flow, and natriuretic activity, as a result of a decrease in renal sympathetic tone. Whereas natriuresis and water diuresis have been demonstrated in animals with acute clonidine or guanabenz administration, this has not been demonstrated in humans. Recent studies in which saline administration was used to precondition humans to a subsequent natriuretic stimulus (i.e., guanabenz-induced decreased renal adrenergic activity) resulted in stabilization of renal blood flow and natriuresis. Selective reduction renal sympathetic activity affecting salt and water transport may explain why guanabenz and probably also clonidine seem to be devoid of the sodium/fluid-retaining properties that are common with other antihypertensive agents. Because agents of this class have effects other than pure central alpha-2 agonism (such as alpha-1 activity), they might have confounding and counterbalancing side effects leading to sodium and water retention.

Role of vascular potassium channels in the regulation of renal hemodynamics

DEFF Research Database (Denmark)

Sørensen, Charlotte Mehlin; Braunstein, Thomas Hartig; von Holstein-Rathlou, Niels-Henrik

2012-01-01

of one or more classes of K+ channels will lead to a change in hemodynamic resistance and therefore of renal blood flow and glomerular filtration pressure. Through these effects, the activity of renal vascular K+ channels influences renal salt and water excretion, fluid homeostasis, and ultimately blood...... pressure. Four main classes of K+ channels [calcium activated (KCa), inward rectifier (Kir), voltage activated (KV), and ATP sensitive (KATP)] are found in the renal vasculature. Several in vitro experiments have suggested a role for individual classes of K+ channels in the regulation of renal vascular...... function. Results from in vivo experiments are sparse. We discuss the role of the different classes of renal vascular K+ channels and their possible role in the integrated function of the renal microvasculature. Since several pathological conditions, among them hypertension, are associated with alterations...

MRI to assess renal structure and function.

Science.gov (United States)

Artunc, Ferruh; Rossi, Cristina; Boss, Andreas

2011-11-01

In addition to excellent anatomical depiction, MRI techniques have expanded to study functional aspects of renal physiology, such as renal perfusion, glomerular filtration rate (GFR) or tissue oxygenation. This review will focus on current developments with an emphasis on clinical applicability. The method of GFR determination is largely heterogeneous and still has weaknesses. However, the technique of employing liver disappearance curves has been shown to be accurate in healthy persons and patients with chronic kidney disease. In potential kidney donors, complete evaluation of kidney anatomy and function can be accomplished in a single-stop investigation. Techniques without contrast media can be utilized to measure renal tissue oxygenation (blood oxygen level-dependent MRI) or perfusion (arterial spin labeling) and could aid in the diagnosis and treatment of ischemic renal diseases, such as renal artery stenosis. Diffusion imaging techniques may provide information on spatially restricted water diffusion and tumor cellularity. Functional MRI opens new horizons in studying renal physiology and pathophysiology in vivo. Although extensively utilized in research, labor-intensive postprocessing and lack of standardization currently limit the clinical applicability of functional MRI. Further studies are necessary to evaluate the clinical value of functional magnetic resonance techniques for early discovery and characterization of kidney disease.

Continuous renal replacement therapy improves renal recovery from acute renal failure.

Science.gov (United States)

Jacka, Michael J; Ivancinova, Xenia; Gibney, R T Noel

2005-03-01

Acute renal failure (ARF) occurs in up to 10% of critically ill patients, with significant associated morbidity and mortality. The optimal mode of renal replacement therapy (RRT) remains controversial. This retrospective study compared continuous renal replacement therapy (CRRT) and intermittent hemodialysis (IHD) for RRT in terms of intensive care unit (ICU) and hospital mortality, and renal recovery. We reviewed the records of all patients undergoing RRT for the treatment of ARF over a 12-month period. Patients were compared according to mode of RRT, demographics, physiologic characteristics, and outcomes of ICU and hospital mortality and renal recovery using the Chi square, Student's t test, and multiple logistic regression as appropriate. 116 patients with renal insufficiency underwent RRT during the study period. Of these, 93 had ARF. The severity of illness of CRRT patients was similar to that of IHD patients using APACHE II (25.1 vs 23.5, P = 0.37), but they required significantly more intensive nursing (therapeutic intervention scale 47.8 vs 37.6, P = 0.0001). Mortality was associated with lower pH at presentation (P = 0.003) and increasing age (P = 0.03). Renal recovery was significantly more frequent among patients initially treated with CRRT (21/24 vs 5/14, P = 0.0003). Further investigation to define optimal timing, dose, and duration of RRT may be beneficial. Although further study is needed, this study suggests that renal recovery may be better after CRRT than IHD for ARF. Mortality was not affected significantly by RRT mode.

Development and application of novelty pretreatment method for the concurrent quantitation of eleven water-soluble B vitamins in ultrafiltrates after renal replacement therapy.

Science.gov (United States)

Wirkus, Dorota; Jakubus, Aleksandra; Owczuk, Radosław; Stepnowski, Piotr; Paszkiewicz, Monika

2017-02-01

Continous renal replacement therapy (CRRT) is particularly recommended for septic shock patients in intensive care units. The CRRT technique used most frequently is high volume continuous veno-venous haemofiltration. It provides a high rate of clearance of uremic toxins and inflammatory cytokines. However, it should also be taken into account that substances important for homeostasis may be concurrently unintentionally removed. Accordingly, water-soluble vitamins can be removed during continuous renal replacement therapy, and the estimate of the loss is critical to ensure appropriate supplementation. The aim of this work was to develop a simple methodology for a purification step prior to the LC-MS/MS determination of water-soluble vitamins in ultrafiltrate samples. For this purpose, two types of resin and a mix of resins were used as sorbents for the purification step. Moreover, parameters such as the amount of resin and the extraction time were optimized. The LC-MS/MS method was developed and validated for final determination of 11 vitamins. The results demonstrated the high purification capability of DEAE Sephadex resin with recoveries between 65 and 101% for water-soluble vitamins from ultrafiltrate samples. An optimized method was applied to assess the loss of B-group vitamins in patients after 24h of renal replacement therapy. The loss of vitamins B2, B6 pyridoxamine, B6 pyridoxal, B7, B1, and B5 in ultrafiltrates was similar in all patients. In the native ultrafiltrates, vitamins B6 pyridoxine, B9 and B12 were not detected. Copyright © 2016 Elsevier B.V. All rights reserved.

Renal plasticity in response to feeding in the Burmese python, Python molurus bivittatus.

Science.gov (United States)

Esbaugh, A J; Secor, S M; Grosell, M

2015-10-01

Burmese pythons are sit-and-wait predators that are well adapted to go long periods without food, yet subsequently consume and digest single meals that can exceed their body weight. These large feeding events result in a dramatic alkaline tide that is compensated by a hypoventilatory response that normalizes plasma pH; however, little is known regarding how plasma HCO3(-) is lowered in the days post-feeding. The current study demonstrated that Burmese pythons contain the cellular machinery for renal acid-base compensation and actively remodel the kidney to limit HCO3(-) reabsorption in the post-feeding period. After being fed a 25% body weight meal plasma total CO2 was elevated by 1.5-fold after 1 day, but returned to control concentrations by 4 days post-feeding (d pf). Gene expression analysis was used to verify the presence of carbonic anhydrase (CA) II, IV and XIII, Na(+) H(+) exchanger 3 (NHE3), the Na(+) HCO3(-) co-transporter (NBC) and V-type ATPase. CA IV expression was significantly down-regulated at 3 dpf versus fasted controls. This was supported by activity analysis that showed a significant decrease in the amount of GPI-linked CA activity in isolated kidney membranes at 3 dpf versus fasted controls. In addition, V-type ATPase activity was significantly up-regulated at 3 dpf; no change in gene expression was observed. Both CA II and NHE3 expression was up-regulated at 3 dpf, which may be related to post-prandial ion balance. These results suggest that Burmese pythons actively remodel their kidney after feeding, which would in part benefit renal HCO3(-) clearance. Copyright © 2015 Elsevier Inc. All rights reserved.

Homer W. Smith's contribution to renal physiology.

Science.gov (United States)

Giebisch, Gerhard

2004-01-01

Homer Smith was, for three decades, from the 1930s until his death in 1962, one of the leaders in the field of renal physiology. His contributions were many: he played a major role in introducing and popularizing renal clearance methods, introduced non-invasive methods for the measurement of glomerular filtration rate, of renal blood flow and tubular transport capacity, and provided novel insights into the mechanisms of excretion of water and electrolytes. Homer Smith's contributions went far beyond his personal investigations. He was a superb writer of several inspiring textbooks of renal physiology that exerted great and lasting influence on the development of renal physiology. Smith's intellectual insights and ability for critical analysis of data allowed him to create broad concepts that defined the functional properties of glomeruli, tubules and the renal circulation. A distinguishing feature of Homer Smith's career was his close contact and collaboration, over many years, with several clinicians of his alma mater, New York University. For initiating these pathophysiological investigations, he is justly credited to have advanced, in a major way, our understanding of altered renal function in disease. Smith's lasting scientific impact is also reflected by a whole school of investigators that trained with him and who applied his methods, analyses and concepts to the study of renal function all over the world. So great was his influence and preeminence that Robert Pitts, in his excellent tribute to Homer Smith in the Memoirs of the National Academy of Science states that his death brought an end to what might be aptly called the Smithian Era of renal physiology.

Empagliflozin in the treatment of type 2 diabetes: evidence to date

Directory of Open Access Journals (Sweden)

Shubrook JH

2015-10-01

Full Text Available Jay H Shubrook,1 Babak Baradar Bokaie,2 Sarah E Adkins31Primary Care Department, Clinical Research and Diabetes Services, Touro University College of Osteopathic Medicine, Vallejo, CA, USA; 2The Diabetes Institute at Ohio University, Ohio University, Athens, OH, USA; 3Pharmacy Practice and Administration, College of Pharmacy, Ohio State University, Athens, OH, USA Abstract: In the last decade, researchers have gained a greater understanding of the pathophysiologic mechanisms of type 2 diabetes as a chronic and progressive disease. One of the more recent treatment targets is the kidney. The kidneys become maladaptive in diabetes by increasing the reabsorption of glucose above the normal physiologic renal threshold. This discovery has led to the development of the sodium/glucose cotransporter 2 inhibitors (SGLT2. These agents readjust the renal threshold for glucose reabsorption to a lower level and decrease glucose reabsorption, while increasing urinary glucose when the glucose is above the renal threshold and subsequently lowering plasma glucose. The mechanism of action of the SGLT2 inhibitors is insulin independent, which makes them a novel treatment of diabetes. At the time of preparation of this manuscript, there were three SGLT2 inhibitors available in the US. This manuscript focuses on empagliflozin, the newest SGLT2 inhibitor, the trials in its development, and the clinical data available to date. Further, the authors propose future applications of empagliflozin, including in the treatment of type 1 diabetes, and its potential role in renoprotection. Keywords: SGLT-2 inhibitors, empagliflozin, type 2 diabetes, kidneys, type 1 diabetes, glucosuria

Renal cell carcinoma in patient with crossed fused renal ectopia

Directory of Open Access Journals (Sweden)

Ozgur Cakmak

2016-01-01

Full Text Available Primary renal cell carcinomas have rarely been reported in patients with crossed fused renal ectopia. We presented a patient with right to left crossed fused kidney harbouring renal tumor. The most frequent tumor encountered in crossed fused renal ectopia is renal cell carcinoma. In this case, partial nephrectomy was performed which pave way to preservation of the uninvolved both renal units. Due to unpredictable anatomy, careful preoperative planning and meticulous delineation of renal vasculature is essential for preservation of the uninvolved renal units.

Tolvaptan alleviates excessive fluid retention of nephrotic diabetic renal failure unresponsive to furosemide.

Science.gov (United States)

Takada, Tesshu; Masaki, Tsuguto; Hoshiyama, Ayako; Toki, Takuya; Kamata, Yuji; Shichiri, Masayoshi

2018-04-17

Patients with diabetic nephropathy develop nephrotic syndrome, and may show limited response to conventional therapy. They often require earlier initiation of renal replacement therapy because they become refractory to diuretics, and experience excessive fluid retention. We aimed to investigate the efficacy of tolvaptan, an oral arginine vasopressin type 2 receptor antagonist, in a case series of 14 severe diabetic renal failure patients who were severely refractory to maximal doses of furosemide and had excessive fluid retention despite preserved cardiac function and residual renal function. All 14 patients experienced immediate and sustained water diuretic effects, resulting in alleviation of congestive heart failure. None required initiation of renal replacement therapy. Tolvaptan promptly increased urine volume and free water clearance, reversed progressive fluid retention, and alleviated congestive heart failure. Thus, tolvaptan could serve as a potential adjunct therapy for severe diabetic renal failure patients with excessive fluid retention and congestive heart failure. This article is protected by copyright. All rights reserved.

Microinjection studies of phosphate permeability in rats during mild saline diuresis: influence of acute thyroparathyroidectomy and parathormone administration

International Nuclear Information System (INIS)

Poujeol, P.; Rouffignac, C. de.

1975-01-01

The tubular permeability to phosphate of the different segments of the rat nephron and the influence of parathyroid hormone on such a permeability were investigated. Tracer microinjections of 32 P and 3 H inulin were performed in control, acutely thyroparathyroidectomized (TPTX) and TPTX + PTH animals undergoing saline diuresis. In order to estimate the 32 P reabsorption capacity of the proximal convoluted tubule (PCT), the loop of Henle and the terminal part of the nephron, microinjections were performed in early proximal, late proximal and early distal tubules respectively. The results reported confirm that the renal phosphate reabsorption is under PTH control [fr

Acute Renal Failure Induced by Chinese Herbal Medication in Nigeria

Directory of Open Access Journals (Sweden)

Effiong Ekong Akpan

2015-01-01

Full Text Available Traditional herbal medicine is a global phenomenon especially in the resource poor economy where only the very rich can access orthodox care. These herbal products are associated with complications such as acute renal failure and liver damage with a high incidence of mortalities and morbidities. Acute renal failure from the use of herbal remedies is said to account for about 30–35% of all cases of acute renal failure in Africa. Most of the herbal medications are not usually identified, but some common preparation often used in Nigeria includes “holy water” green water leaves, bark of Mangifera indica (mango, shoot of Anacardium occidentale (cashew, Carica papaya (paw-paw leaves, lime water, Solanum erianthum (Potato tree, and Azadirachta indica (Neem trees. We report a rare case of a young man who developed acute renal failure two days after ingestion of Chinese herb for “body cleansing” and general wellbeing. He had 4 sessions of haemodialysis and recovered kidney function fully after 18 days of admission.

ER stress and basement membrane defects combine to cause glomerular and tubular renal disease resulting from Col4a1 mutations in mice

Directory of Open Access Journals (Sweden)

Frances E. Jones

2016-02-01

Full Text Available Collagen IV is a major component of basement membranes, and mutations in COL4A1, which encodes collagen IV alpha chain 1, cause a multisystemic disease encompassing cerebrovascular, eye and kidney defects. However, COL4A1 renal disease remains poorly characterized and its pathomolecular mechanisms are unknown. We show that Col4a1 mutations in mice cause hypotension and renal disease, including proteinuria and defects in Bowman's capsule and the glomerular basement membrane, indicating a role for Col4a1 in glomerular filtration. Impaired sodium reabsorption in the loop of Henle and distal nephron despite elevated aldosterone levels indicates that tubular defects contribute to the hypotension, highlighting a novel role for the basement membrane in vascular homeostasis by modulation of the tubular response to aldosterone. Col4a1 mutations also cause diabetes insipidus, whereby the tubular defects lead to polyuria associated with medullary atrophy and a subsequent reduction in the ability to upregulate aquaporin 2 and concentrate urine. Moreover, haematuria, haemorrhage and vascular basement membrane defects confirm an important vascular component. Interestingly, although structural and compositional basement membrane defects occurred in the glomerulus and Bowman's capsule, no tubular basement membrane defects were detected. By contrast, medullary atrophy was associated with chronic ER stress, providing evidence for cell-type-dependent molecular mechanisms of Col4a1 mutations. These data show that both basement membrane defects and ER stress contribute to Col4a1 renal disease, which has important implications for the development of treatment strategies for collagenopathies.

Na/K-ATPase Signaling and Salt Sensitivity: The Role of Oxidative Stress

Directory of Open Access Journals (Sweden)

Jiang Liu

2017-03-01

Full Text Available Other than genetic regulation of salt sensitivity of blood pressure, many factors have been shown to regulate renal sodium handling which contributes to long-term blood pressure regulation and have been extensively reviewed. Here we present our progress on the Na/K-ATPase signaling mediated sodium reabsorption in renal proximal tubules, from cardiotonic steroids-mediated to reactive oxygen species (ROS-mediated Na/K-ATPase signaling that contributes to experimental salt sensitivity.

Chronic renal failure due to unilateral renal agenesis and total renal dysplasia (=aplasia)

International Nuclear Information System (INIS)

Kroepelin, T.; Ziupa, J.; Wimmer, B.

1983-01-01

Three adult patients with unilateral renal agenesis/total dysplasia (= aplasia) and with an early chronic renal failure are presented. One patient had renal agenesis without ureter bud and ureteric ostium on one side, and reflux pyelonephritis on the other; one had small compact total renal dysplasia (= aplasia) on one side, while chronic uric acid nephropathy (chronic renal disease as a cause of gout) was diagnosed on the other; the third patient had a total large multicystic dysplasia on one side, and on the other a segmental large multicystic dysplasia. Radiological steps and radiodiagnostic criteria are discussed and the combination of urogenital and extraurogenital anomalies is referred to. (orig.)

Efficacy of ultrasonography-guided renal biopsy for the evaluation of renal dysfunction following renal transplantation

International Nuclear Information System (INIS)

Kim, Young Jae; Choi, Chul Soon; Min, Seon Jeong; Lee, Gyung Kyu; Lee, Eil Seong; Kang, Ik Won; Bae, Sang Hoon

2003-01-01

To evaluate the usefulness and complications of renal biopsy under ultrasonography-guidance in renal dysfunction after renal transplantation. Ultrasonography-guided renal biopsy was done in 47 patients with the transplanted kidney. The subjects consisted of 30 males and 17 females, age ranged from 16 to 66 years (average age=38 years). Biopsies were done once in 27 patients, twice in 17 patients, three times in 3 patients, a total of 70 biopsies. The success rate of renal biopsy for the accurate pathologic diagnosis and the incidence and types of complications following biopsy were evaluated. The success rate of renal biopsy for the accurate pathologic diagnosis was 96%(67/70). Pathologic diagnosis included 27 cases of acute rejection (39%), 8 cases of acute tubular necrosis (11%), 4 cases of acute rejection and acute tubular necrosis (6%), 4 cases of cyclosporin toxicity (6%), 4 cases of primary disease recurrence (6%), 4 cases of infection (6%) and others. Complications after renal biopsy included 15 cases of microscopic hematuria (21%), 1 case of gross hematuria with spontaneous cessation and 1 case of life threatening hemorrhage. Ultrasonography-guided renal biopsy is a safe and effective diagnostic method for the evaluation of renal dysfunction following renal transplantation.

RNA sequencing of kidney distal tubule cells reveals multiple mediators of chronic aldosterone action

DEFF Research Database (Denmark)

Poulsen, Søren Brandt; Limbutara, Kavee; Fenton, Robert Andrew

2018-01-01

The renal aldosterone-sensitive distal tubule (ASDT) is crucial for sodium reabsorption and blood pressure regulation. The ASDT consists of the late distal convoluted tubule (DCT2), connecting tubule (CNT) and collecting duct. Due to difficulties in isolating epithelial cells from the ASDT in lar...

The Renal Renin-Angiotensin System

Science.gov (United States)

Harrison-Bernard, Lisa M.

2009-01-01

The renin-angiotensin system (RAS) is a critical regulator of sodium balance, extracellular fluid volume, vascular resistance, and, ultimately, arterial blood pressure. In the kidney, angiotensin II exerts its effects to conserve salt and water through a combination of the hemodynamic control of renal blood flow and glomerular filtration rate and…

Aging and physiological changes of the kidneys including changes in glomerular filtration rate.

Science.gov (United States)

Musso, Carlos G; Oreopoulos, Dimitrios G

2011-01-01

In addition to the structural changes in the kidney associated with aging, physiological changes in renal function are also found in older adults, such as decreased glomerular filtration rate, vascular dysautonomia, altered tubular handling of creatinine, reduction in sodium reabsorption and potassium secretion, and diminished renal reserve. These alterations make aged individuals susceptible to the development of clinical conditions in response to usual stimuli that would otherwise be compensated for in younger individuals, including acute kidney injury, volume depletion and overload, disorders of serum sodium and potassium concentration, and toxic reactions to water-soluble drugs excreted by the kidneys. Additionally, the preservation with aging of a normal urinalysis, normal serum urea and creatinine values, erythropoietin synthesis, and normal phosphorus, calcium and magnesium tubular handling distinguishes decreased GFR due to normal aging from that due to chronic kidney disease. Copyright © 2011 S. Karger AG, Basel.

“Transcollateral” Renal Angioplasty for a Completely Occluded Renal Artery

International Nuclear Information System (INIS)

Chandra, Subash; Chadha, Davinder S.; Swamy, Ajay

2011-01-01

Percutaneous transluminal renal angioplasty with stenting has been effective in the control of hypertension, renal function, and pulmonary edema caused by atherosclerotic renal artery stenosis. However, the role of the procedure has not been fully established in the context of chronic total occlusion of renal artery. We report the successful use of this procedure in 57-year-old male patient who reported for evaluation of a recent episode of accelerated hypertension. A renal angiogram in this patient showed ostial stenosis of the right renal artery, which was filling by way of the collateral artery. Renal angioplasty for chronic total occlusion of right renal artery was successfully performed in a retrograde fashion through a collateral artery, thereby leading to improvement of renal function and blood pressure control.

Swine as a model in renal physiology and nephrology: an overview

International Nuclear Information System (INIS)

Terris, J.M.

1986-01-01

Swine have become an important animal model in many areas of biomedical research for a variety of reasons. They are suited for studies in nephrology and renal physiology because they are the only mammal, with the exception of the dwarf water buffalo, which has been shown to have kidneys morphologically similar to the human. Maturational characteristics of fetal and neonatal kidney are similar to those of the newborn human infant. Therefore, studies to evaluate the pyeloureteral dynamics of human like multipapillary kidneys or developmental studies related to the newborn human cannot be conducted adequately in any other mammal. The following overview addresses the morphology and pelvic and ureteral dynamics of swine and human kidneys, maturation of renal hemodynamics in the neonate, renal function and the effects of anesthesia and diruetics on renal function in the pig. Additionally, the use of swine in other areas of interest to the nephrologist and renal physiologist are considered, eg, renal response to exercise, irradiation therapy, kidney preservation and renal transplantation

Parametric Study of Hybrid Argon-Water Stabilized Electric Arc under Subsonic and Supersonic Regimes

Czech Academy of Sciences Publication Activity Database

Jeništa, Jiří; Hrabovský, Milan; Nishiyama, H.; Takana, H.; Bartlová, M.; Aubrecht, V.

2010-01-01

Roč. 14, č. 1 (2010), s. 63-76 ISSN 1093-3611 R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : argon mass flow rate * divergence of radiation flux * partial characteristics * reabsorption * shock diamonds * water plasma torch Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.189, year: 2010

Adaptive strategies for post-renal handling of urine in birds

DEFF Research Database (Denmark)

Laverty, Gary; Skadhauge, Erik

2008-01-01

Birds are a diverse vertebrate class in terms of diet and habitat, but they share several common physiological features, including the use of uric acid as the major nitrogenous waste product and the lack of a urinary bladder. Instead, ureteral urine refluxes from the urodeum into the more proximal...... coprodeum and portions of the hindgut (colon or rectum and ceca). This presents a potential problem in that hyperosmotic ureteral urine in contact with the permeable epithelia of these tissues would counteract renal osmotic work. This review describes and provides examples of different strategies used...... by avian species to balance renal and post-renal changes in urien composition. The strategies described include: 1. a "reptilian" mode, with moderate renal concentrating ability, but high rates of post-renal salt and water resorption; 2. the "mammalian" strategy, in which the coprodeum effectively...

Influences of renal stone surgeries on renal function; Evaluation of renal function with sup 99m Tc-DMSA renal scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Katayama, Yasushi (Niigata Univ. (Japan). School of Medicine)

1991-10-01

From 1984 to 1990, {sup 99m}Tc-DMSA renal scintigraphy was performed before and after nephrolithotomy (15 cases), pyelolithotomy (15 cases), percutaneous nephrolithotripsy (PNL: 15 cases) and extracorporeal shock wave lithotripsy (ESWL: 16 cases, 17 kidneys) in order to evaluate of influences of renal stone surgeries on split renal function. DMSA renal uptake change ratio of treated kidneys of nephrolithotomy (-24.94{+-}5.60%) was significantly lower than that of PNL (-0.06{+-}3.92%), pyelolithotomy (-4.08{+-}4.79%) (p<0.01) and ESWL (-7.72{+-}3.87%) (p<0.05). The average change ratios of contralateral kidneys were as follows: PNL 4.80{+-}4.21% nephrolithotomy 4.67{+-}4.73%, pyelolithotomy -1.46{+-}5.39% and ESWL -2.02{+-}4.44%. One to 3 weeks after PNL, the cold area on the renal image was found in 10 (66.7%) of 15 cases. In cases of ESWL, DMSA renal uptake decreased even 4-10 weeks (mean 7 weeks) after treatment. In conclusion, possibility of deterioration of renal function after ESWL was suggested. (author).

Renal Osteodystrophy

Directory of Open Access Journals (Sweden)

Aynur Metin Terzibaşoğlu

2004-12-01

Full Text Available Chronic renal insufficiency is a functional definition which is characterized by irreversible and progressive decreasing in renal functions. This impairment is in collaboration with glomeruler filtration rate and serum creatinine levels. Besides this, different grades of bone metabolism disorders develop in chronic renal insufficiency. Pathologic changes in bone tissue due to loss of renal paranchyme is interrelated with calcium, phosphorus vitamine-D and parathyroid hormone. Clinically we can see high turnover bone disease, low turnover bone disease, osteomalacia, osteosclerosis and osteoporosis in renal osteodystropy. In this article we aimed to review pathology of bone metabolism disorders due to chronic renal insufficiency, clinic aspects and treatment approaches briefly.

CT differentiation of infiltrating renal cell carcinoma and renal urothelial tumor

International Nuclear Information System (INIS)

Choi, Hyo Kyeong; Goo, Dong Erk; Bang, Sun Woo; Lee, Moon Gyu; Cho, Kyoung Sik; Auh, Yong Ho

1994-01-01

It may be difficult to differentiate renal cell carcinoma involving collecting system from renal urothelial tumor invading into renal parenchyma. The purpose of this study was to assess the differences of CT findings between two conditions. CT findings of 5 cases of renal cell carcinoma involving the renal collecting systems and 10 cases of renal urothelial tumors invading the renal parenchyma were compared, and analyzed about the presence or absence of hydronephrosis, normal or abnormal CT nephrogram, renal contour changes due to mass and tentative diagnosis. The diagnoses were confirmed at surgery. Renal cell carcinoma showed hydronephrosis in only 20% and normal CT nephrogram and outward contour bulging in all cases. In contrast, renal urothelial tumor showed hydronephrosis(70%), abnormal CT nephrogram(60%), and preservation of reinform shape(100%). Renal contour changes and CT nephrogram may be useful in distinguishing both disease entities

Urinary excretion of Tamm-Horsfall protein and epidermal growth factor in chronic nephropathy

DEFF Research Database (Denmark)

Torffvit, O; Jørgensen, P E; Kamper, A L

1998-01-01

rate (GFR) as an indicator for the general renal function, lithium clearance (C(Li)) as an indicator for proximal tubular function, and absolute distal reabsorption of sodium (ADR(Na)) as an indicator for distal tubular function. The excretion rate of EGF was rather closely correlated with GFR, C......(Li) and ADR(Na) (Spearman coefficients of variation 0.88, 0.69, and 0.74, respectively). The correlations between the excretion rate of THP and GFR, C(Li) and ADR(Na) were weaker (Spearman coefficients of variation 0.68, 0.42, and 0.44). When the effect of GFR had been accounted for by multiple variance...... analyses, the excretion rates of the two peptides were still associated with ADR(Na) but not with C(Li). In conclusion, the urinary excretion rates of especially EGF but also those of THP were correlated with renal function and distal tubular reabsorption of sodium in patients with chronic nephropathy....

A case–control study on environmental and biological risk factors for renal calculi persisting in a coastal Union Territory, India

Directory of Open Access Journals (Sweden)

Prakash Mathiyalagen

2017-01-01

Full Text Available Background and Objectives: Renal stone disease is a common disorder of the urinary tract and also a significant problem because of incidence, recurrence, and severe consequences. The complex pathogenetic mechanisms of renal stone formation involve both biologic and environmental risk factors. The present study was performed to identify the role of these parameters among renal stone patients and normal individuals from a coastal union territory region in South India. Methods: The authors conducted a case–control study of renal stone disease among outpatient department patients more than 30 years of age using systematic random sampling procedure with 100 study participants (50 subjects for each group. A questionnaire to explore some relevant history as well as to note general examination findings was used along with a house visit to collect a sample of water. Analysis was undertaken using appropriate statistical techniques. Results: The study showed statistically significant association for renal stones with female sex, illiteracy, body mass index (BMI (>25 kg/m2, sodium (>50 mg/L, water consumption (<1.5 L/day, water source being borewell, consuming soft drink, sedentary work, and family history of renal stones. The adjusted odds ratios (ORs were significantly higher for consuming soft drink (OR: 8.19; 95% confidence interval: 1.99–33.69, sedentary work (10.01; 1.27–78.91, and water consumption < 1.5 L/day (7.73; 2.24–26.69. Interpretation and Conclusions: We conclude that in this part of India, female gender, illiteracy, high BMI, high sodium in drinking water, inadequate water consumption, borewell drinking water, soft-drink consumption, sedentary work, and family history of renal stones can lead to a significant increase in the risk of renal stone disease.

The role of the kidney in compensating the alkaline tide, electrolyte load, and fluid balance disturbance associated with feeding in the freshwater rainbow trout, Oncorhynchus mykiss.

Science.gov (United States)

Bucking, Carol; Landman, Michael J; Wood, Chris M

2010-05-01

The effect in freshwater rainbow trout of digesting a commercial pellet meal on the renal handling of water, ions and acid-base equivalents was investigated through urine collection over a 48 h period following meal ingestion. The glomerular filtration rate (GFR) and urine flow rate (UFR) were reduced in fed fish between 12 and 24h following the meal, likely reflecting a loss of endogenous water across the gastric epithelium as a result of ingesting dry, ion-rich food pellets. The kidney was also responsible for the excretion of some excess dietary Ca(2+), and, to a much lesser extent, Na(+) and Cl(-), while the urinary excretion of K(+) was unaffected. The most dramatic effect of feeding was the elevation of renal Mg(2+) excretion, with the kidney transitioning from net Mg(2+) reabsorption to net Mg(2+) secretion during digestion. The renal handling of dietary ions accounted for 3-27% of the total ions absorbed from the diet, indicating that a majority of the ions are excreted extra-renally or incorporated into growth. However this does highlight the underestimation of renal ion handling when using unfed fish models. The metabolic alkalosis created by digestion (the alkaline tide) resulted in an increase in urine pH as well as a transition from net acidic equivalent excretion in the urine to net basic equivalent excretion. This was due to a decrease in the titratable acidity minus bicarbonate component of urine as well as a decrease in ammonia secretion. Additionally, the experimental separation of the urinary component of acid-base excretion from that of the gills highlighted the substantially larger contribution of the latter. During the alkaline tide, renal excretion accounted for approximately 5% of the total basic equivalent excretion to the external water. Copyright 2009 Elsevier Inc. All rights reserved.

Neuroendocrine and renal effects of intravascular volume expansion in compensated heart failure

DEFF Research Database (Denmark)

Gabrielsen, A; Bie, P; Holstein-Rathlou, N H

2001-01-01

To examine if the neuroendocrine link between volume sensing and renal function is preserved in compensated chronic heart failure [HF, ejection fraction 0.29 +/- 0.03 (mean +/- SE)] we tested the hypothesis that intravascular and central blood volume expansion by 3 h of water immersion (WI) elicits...... sustained angiotensin-converting enzyme inhibitor therapy, n = 9) absolute and fractional sodium excretion increased (P Renal free water clearance increased during WI in control subjects but not in HF......, albeit plasma vasopressin concentrations were similar in the two groups. In conclusion, the neuroendocrine link between volume sensing and renal sodium excretion is preserved in compensated HF. The natriuresis of WI is, however, modulated by the prevailing ANG II and Aldo concentrations. In contrast...

The renal scan in pregnant renal transplant patients

International Nuclear Information System (INIS)

Goldstein, H.A.; Ziessman, H.A.; Fahey, F.H.; Collea, J.V.; Alijani, M.R.; Helfrich, G.B.

1985-01-01

With the greater frequency of renal transplant surgery, more female pts are becoming pregnant and carrying to term. In the renal allograft blood vessels and ureter may be compressed resulting in impaired renal function and/or, hypertension. Toxemia of pregnancy is seen more frequently than normal. Radionuclide renal scan monitoring may be of significant value in this high risk obstetrical pt. After being maintained during the pregnancy, renal function may also deteriorate in the post partum period. 5 pregnant renal transplant pts who delivered live babies had renal studies with Tc-99m DTPA to assess allograft perfusion and function. No transplanted kidney was lost during or after pregnancy as a result of pregnancy. No congenital anomalies were associated with transplant management. 7 studies were performed on these 5 pts. The 7 scans all showed the uterus/placenta. The bladder was always distorted. The transplanted kidney was rotated to a more vertical position in 3 pts. The radiation dose to the fetus is calculated at 0.024 rad/mCi administered. This study demonstrates the anatomic and physiologic alterations expected in the transplanted kidney during pregnancy when evaluated by renal scan and that the radiation burden may be acceptable in management of these pts

Changes in forearm muscle temperature alter renal vascular responses to isometric handgrip.

Science.gov (United States)

Kuipers, Nathan T; Sauder, Charity L; Kearney, Matthew L; Ray, Chester A

2007-12-01

The purpose of the present study was to examine the effect of heating and cooling the forearm muscles on renal vascular responses to ischemic isometric handgrip (IHG). It was hypothesized that heating and cooling the forearm would augment and attenuate, respectively, renal vascular responses to IHG. Renal vascular responses to IHG were studied during forearm heating at 39 degrees C (n = 15, 26 +/- 1 yr) and cooling at 26 degrees C (n = 12, 26 +/- 1 yr). For a control trial, subjects performed the experimental protocol while the forearm was normothermic (approximately 34 degrees C). Muscle temperature (measured by intramuscular probe) was controlled by changing the temperature of water cycling through a water-perfused sleeve. The experimental protocol was as follows: 3 min at baseline, 1 min of ischemia, ischemic IHG to fatigue, and 2 min of postexercise muscle ischemia. At rest, renal artery blood velocity (RBV; Doppler ultrasound) and renal vascular conductance (RVC = RBV/mean arterial blood pressure) were not different between normothermia and the two thermal conditions. During ischemic IHG, there were greater decreases in RBV and RVC in the heating trial. However, RBV and RVC were similar during postexercise muscle ischemia during heating and normothermia. RVC decreased less during cooling than in normothermia while the subjects performed the ischemic IHG protocol. During postexercise muscle ischemia, RVC was greater during cooling than in normothermia. These results indicate that heating augments mechanoreceptor-mediated renal vasoconstriction whereas cooling blunts metaboreceptor-mediated renal vasoconstriction.

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

DEFF Research Database (Denmark)

Tingskov, Stine Julie; Hu, Shan; Frøkiær, Jorgen

2018-01-01

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 one week after onset of lithium administration. Lithium treatment resulted in severe polyuria and reduced AQP2 expression, which was ameliorated by TAM. Consistent with this, TAM attenuated downregulation...... of AQP2 and increased phosphorylation of the cAMP responsive element binding protein (CREB), which induced AQP2 expression, in freshly isolated inner medullary collecting duct suspension prepared from lithium-treated rats. In conclusion, TAM attenuated dose-dependently polyuria, impaired urine...

Increased Urinary Extracellular Vesicle Sodium Transporters in Cushing's Syndrome with Hypertension.

Science.gov (United States)

Salih, Mahdi; Bovée, Dominique M; van der Lubbe, Nils; Danser, Alexander H J; Zietse, Robert; Feelders, Richard A; Hoorn, Ewout J

2018-05-02

Increased renal sodium reabsorption contributes to hypertension in Cushing's syndrome (CS). Renal sodium transporters can be analyzed non-invasively in urinary extracellular vesicles (uEVs). To analyze renal sodium transporters in uEVs of patients with CS and hypertension. Observational study. University hospital. uEVs were isolated by ultracentrifugation and analyzed by immunoblotting in 10 CS patients and 7 age-matched healthy subjects. In 7 CS patients uEVs were analyzed before and after treatment. uEV protein abundance. The 10 CS patients were divided in those with suppressed and non-suppressed renin-angiotensin-aldosterone system (RAAS, n = 5/group). CS patients with suppressed RAAS had similar blood pressure but significantly lower serum potassium than CS patients with non-suppressed RAAS. Compared to healthy subjects, only those with suppressed RAAS had higher phosphorylated Na+-K+-Cl- cotransporter type 2 (pNKCC2) and higher total and phosphorylated Na+-Cl- cotransporter (NCC) in uEVs. Serum potassium but not urinary free cortisol correlated with pNKCC2, pNCC, and NCC in uEVs. Treatment of CS reversed the increases in pNKCC2, NCC, and pNCC. CS increases renal sodium transporter abundance in uEVs especially in patients with hypertension and suppressed RAAS. As potassium has recently been identified as an important driver of NCC activity, low serum potassium may also contribute to increased renal sodium reabsorption and hypertension in CS. These results may also be relevant for hypertension induced by exogenous glucocorticoids.

Renal perfusion scintiscan

Science.gov (United States)

... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

Nitric oxide synthase inhibition does not improve renal function in cirrhotic patients with ascites

DEFF Research Database (Denmark)

Thiesson, Helle C; Skøtt, Ole; Jespersen, Bente

2003-01-01

because of a reduction in renal blood flow of up to 29.1 +/- 8.1% (p inhibition of NO synthesis does not improve sodium and water excretion in decompensated cirrhosis, probably because of an accompanying decrease in renal...

Probing SGLT2 as a therapeutic target for diabetes: Basic physiology and consequences

Science.gov (United States)

Gallo, Linda A; Wright, Ernest M; Vallon, Volker

2018-01-01

Traditional treatments for type 1 and type 2 diabetes are often associated with side effects, including weight gain and hypoglycaemia that may offset the benefits of blood glucose lowering. The kidneys filter and reabsorb large amounts of glucose, and urine is almost free of glucose in normoglycaemia. The sodium-dependent glucose transporter (SGLT)-2 in the early proximal tubule reabsorbs the majority of filtered glucose. Remaining glucose is reabsorbed by SGLT1 in the late proximal tubule. Diabetes enhances renal glucose reabsorption by increasing the tubular glucose load and the expression of SGLT2 (as shown in mice), which maintains hyperglycaemia. Inhibitors of SGLT2 enhance urinary glucose excretion and thereby lower blood glucose levels in type 1 and type 2 diabetes. The load-dependent increase in SGLT1-mediated glucose reabsorption explains why SGLT2 inhibitors in normoglycaemic conditions only excrete ~50% of the filtered glucose. The role of SGLT1 in both renal and intestinal glucose reabsorption provides a rationale for the development of dual SGLT1/2 inhibitors. SGLT2 inhibitors lower blood glucose levels independent of insulin and induce pleiotropic actions that may be relevant in the context of lowering cardiovascular risk. Ongoing long-term clinical studies will determine whether SGLT2 inhibitors have a safety profile and exert cardiovascular benefits that are superior to traditional agents. PMID:25616707

SGLT2 inhibition in the diabetic kidney – an update

Science.gov (United States)

Novikov, Aleksandra; Vallon, Volker

2016-01-01

Purpose of review The sodium glucose cotransporter SGLT2 reabsorbs most of the glucose filtered by the kidneys. SGLT2 inhibitors reduce glucose reabsorption thereby lowering blood glucose levels and have been approved as new anti-hyperglycemic drugs. While the therapeutic strategy is very promising, many questions remain. Recent findings Using validated antibodies SGLT2 expression was localized to the brush border of the early proximal tubule in human kidney and was found upregulated in genetic murine models of type 1 and 2 diabetes. SGLT2 may functionally interact with the Na/H exchanger NHE3 in the proximal tubule. SGLT1-mediated reabsorption explains the fractional glucose reabsorption of 40–50% during SGLT2 inhibition. SGLT2 is expressed on pancreatic alpha cells where its inhibition induces glucagon secretion. SGLT2 inhibition lowers GFR in hyperfiltering diabetic patients consistent with the tubular hypothesis of diabetic hyperfiltration. New data indicate a potential of SGLT2 inhibition for renal medullary hypoxia and ketoacidosis, but also for blood glucose effect-dependent and independent nephroprotective actions, renal gluconeogenesis inhibition, reduction in cardiovascular mortality, and cancer therapy. Summary The findings expand and refine our understanding of SGLT2 and its inhibition, have relevance for clinical practice, and will help interpret ongoing clinical trials on the long-term safety and cardiovascular effects of SGLT2 inhibitors. PMID:26575393

Study of acute renal insufficiency and chronic renal insufficiency using radioisotopes

International Nuclear Information System (INIS)

Raynaud, C.

1976-01-01

Radioisotopic renal function tests are of assistance to diagnose and follow-up the course of renal insufficiency. The radioisotopic renogram is useful in assessing the response to therapy of child obstructive uropathies and evaluating renal transplant function. The renal scan is helpful, in an emergency service, to differenciate chronic renal insufficiency from acute renal insufficiency. Hg renal uptake test provides informations on physiopathological problems. Among them, the following problems are emphasized: evolution of a nonfunctioning kidney, control of the success of a reparative surgery and of bilateral obstructive uropathies with unilateral symptoms [fr

Magnetization Transfer Magnetic Resonance Imaging Noninvasively Detects Renal Fibrosis in Swine Atherosclerotic Renal Artery Stenosis at 3.0 T.

Science.gov (United States)

Jiang, Kai; Ferguson, Christopher M; Woollard, John R; Zhu, Xiangyang; Lerman, Lilach O

2017-11-01

Renal fibrosis is a useful biomarker for diagnosis and evaluation of therapeutic interventions of renal diseases but often requires invasive testing. Magnetization transfer magnetic resonance imaging (MT-MRI), which evaluates the presence of macromolecules, offers a noninvasive tool to probe renal fibrosis in murine renal artery stenosis (RAS) at 16.4 T. In this study, we aimed to identify appropriate imaging parameters for collagen detection at 3.0 T MRI and to test the utility of MT-MRI in measuring renal fibrosis in a swine model of atherosclerotic RAS (ARAS). To select the appropriate offset frequency, an MT-MRI study was performed on a phantom containing 0% to 40% collagen I and III with offset frequencies from -1600 to +1600 Hz and other MT parameters empirically set as pulse width at 16 milliseconds and flip angle at 800 degrees. Then selected MT parameters were used in vivo on pigs 12 weeks after sham (n = 8) or RAS (n = 10) surgeries. The ARAS pigs were fed with high-cholesterol diet to induce atherosclerosis. The MT ratio (MTR) was compared with ex vivo renal fibrosis measured using Sirius-red staining. Offset frequencies at 600 and 1000 Hz were selected for collagen detection without direct saturation of free water signal, and subsequently applied in vivo. The ARAS kidneys showed mild cortical and medullary fibrosis by Sirius-red staining. The cortical and medullary MTRs at 600 and 1000 Hz were both increased. Renal fibrosis measured ex vivo showed good linear correlations with MTR at 600 (cortex: Pearson correlation coefficient r = 0.87, P 3.0 T. Therefore, MT-MRI may potentially be clinically applicable and useful for detection and monitoring of renal pathology in subjects with RAS.

Distal renal tubular acidosis in recurrent renal stone formers

DEFF Research Database (Denmark)

Osther, P J; Hansen, A B; Røhl, H F

1989-01-01

Renal acidification ability was examined in 90 recurrent renal stone formers, using fasting morning urinary pH levels followed by a short ammonium chloride loading test in subjects with pH levels above 6.0. Fifteen patients (16.6%) revealed a distal renal tubular acidification defect: one patient......, this has important therapeutic implications. The pathological sequence in renal stone formers with dRTA is discussed....

Screening renal stone formers for distal renal tubular acidosis

DEFF Research Database (Denmark)

Osther, P J; Hansen, A B; Røhl, H F

1989-01-01

A group of 110 consecutive renal stone formers were screened for distal renal tubular acidosis (RTA) using morning fasting urinary pH (mfUpH) levels followed by a short ammonium chloride loading test in patients with levels above 6.0. In 14 patients (12.7%) a renal acidification defect was noted...... RTA in renal stone formers. Regardless of whether the acidification defect is primary or secondary to stone formation, however, all renal stone formers with distal RTA can expect to benefit from prophylactic alkaline therapy and it is recommended that the screening procedure, which is easy to use...

Acute renal infarction Secondary to Atrial Fibrillation Mimicking Renal Stone Picture

International Nuclear Information System (INIS)

Salih, Salih Bin; Al-Durihim, H.; Al-Jizeeri, A.; Al-Maziad, G.

2006-01-01

Acute renal infarction presents in a similar clinical picture to that of a renal stone. We report a 55-year-old Saudi female, known to have atrial fibrillation secondary to mitral stenosis due to rheumatic heart disease. She presented with a two day history of right flank pain that was treated initially as renal stone. Further investigations confirmed her as a case of renal infarction. Renal infarction is under-diagnosed because the similarity of its presentation to renal stone. Renal infarction should be considered in the differential diagnosis of loin pain, particularly in a patient with atrial fibrillation. (author)

Results, meta-analysis and a first evaluation of UNOxR, the urinary nitrate-to-nitrite molar ratio, as a measure of nitrite reabsorption in experimental and clinical settings.

Science.gov (United States)

Tsikas, Dimitrios; Hanff, Erik; Bollenbach, Alexander; Kruger, Ruan; Pham, Vu Vi; Chobanyan-Jürgens, Kristine; Wedekind, Dirk; Arndt, Tanja; Jörns, Anne; Berbée, Jimmy F P; Princen, Hans M G; Lücke, Thomas; Mariotti, François; Huneau, Jean-François; Ückert, Stefan; Frölich, Jürgen C; Lenzen, Sigurd

2018-05-04

We recently found that renal carbonic anhydrase (CA) is involved in the reabsorption of inorganic nitrite (NO 2 - ), an abundant reservoir of nitric oxide (NO) in tissues and cells. Impaired NO synthesis in the endothelium and decreased NO bioavailability in the circulation are considered major contributors to the development and progression of renal and cardiovascular diseases in different conditions including diabetes. Isolated human and bovine erythrocytic CAII and CAIV can convert nitrite to nitrous acid (HONO) and its anhydride N 2 O 3 which, in the presence of thiols (RSH), are further converted to S-nitrosothiols (RSNO) and NO. Thus, CA may be responsible both for the homeostasis of nitrite and for its bioactivation to RSNO/NO. We hypothesized that enhanced excretion of nitrite in the urine may contribute to NO-related dysfunctions in the renal and cardiovascular systems, and proposed the urinary nitrate-to-nitrite molar ratio, i.e., U NOx R, as a measure of renal CA-dependent excretion of nitrite. Based on results from clinical and experimental animal studies, here, we report on a first evaluation of U NOx R. We determined U NOx R values in preterm neonates, healthy children, and adults, in children suffering from type 1 diabetes mellitus (T1DM) or Duchenne muscular dystrophy (DMD), in elderly subjects suffering from chronic rheumatic diseases, type 2 diabetes mellitus (T2DM), coronary artery disease (CAD), or peripheral arterial occlusive disease (PAOD). We also determined U NOx R values in healthy young men who ingested isosorbide dinitrate (ISDN), pentaerythrityl tetranitrate (PETN), or inorganic nitrate. In addition, we tested the utility of U NOx R in two animal models, i.e., the LEW.1AR1-iddm rat, an animal model of human T1DM, and the APOE*3-Leiden.CETP mice, a model of human dyslipidemia. Mean U NOx R values were lower in adult patients with rheumatic diseases (187) and in T2DM patients of the DALI study (74) as compared to healthy elderly adults

Renal aquaporins and sodium transporters with special focus on urinary tract obstruction

DEFF Research Database (Denmark)

Frøkiaer, Jørgen; Li, Chunling; Shi, Yimin

2003-01-01

seven aquaporins are expressed at distinct sites in the kidney and 4 members of this family (AQP1-4) have been demonstrated to play pivotal roles in the physiology and pathophysiology for renal regulation of body water balance. Osmotic equilibration via renal aquaporins is maintained by active transport......The discovery of aquaporin-1 (AQP1) by Agre and colleagues explained the long-standing biophysical question of how water specifically crosses biological membranes. These studies led to the discovery and identification of a whole new family of membrane proteins, the aquaporins. At present, at least...

Secretory NaCl and volume flow in renal tubules.

Science.gov (United States)

Beyenbach, K W

1986-05-01

This review attempts to give a retrospective survey of the available evidence concerning the secretion of NaCl and fluid in renal tubules of the vertebrate kidney. In the absence of glomerular filtration, epithelial secretory mechanisms, which to this date have not been elucidated, are responsible for the renal excretion of NaCl and water in aglomerular fish. However, proximal tubules isolated from glomerular fish kidneys of the flounder, killifish, and the shark also have the capacity to secrete NaCl and fluid. In shark proximal tubules, fluid secretion appears to be driven via secondary active transport of Cl. In another marine vertebrate, the sea snake, secretion of Na (presumably NaCl) and fluid is observed in freshwater-adapted and water-loaded animals. Proximal tubules of mammals can be made to secrete NaCl in vitro together with secretion of aryl acids. An epithelial cell line derived from dog kidney exhibits secondary active secretion of Cl when stimulated with catecholamines. Tubular secretion of NaCl and fluid may serve a variety of renal functions, all of which are considered here. The occurrence of NaCl and fluid secretion in glomerular proximal tubules of teleosts, elasmobranchs, and reptiles and in mammalian renal tissue cultures suggests that the genetic potential for NaCl secretion is present in every vertebrate kidney.

A Mathematical Model of Renal Blood Distribution Coupling TGF, MR and Tubular System

Institute of Scientific and Technical Information of China (English)

GAO Ci-xiu; YANG Lin; WANG Ke-qiang; XU Shi-xiong; DAI Pei-dong

2009-01-01

Objective:To investigate the relationship between renal blood distribution and the physiological activities of the kidney. Methods:A mathematical model is developed based on Hagan-Poiseuille law and mass transport, coupling mechanics of myogenic response (MR), tubuloglomerular feedback (TGF) and the tubular system in the renal medulla. The model parameters, including the permeability coefficients, the vascular lumen radius and the solute concentration at the inlet of the tubes, are derived from the experimental results. Simulations of the blood and water flow in the loop of Henel, the collecting duct and vas rectum, are carried out by the model of the tubular system in the renal medulla, based on conservations of water and solutes for transmural transport. Then the tubular model is coupled with MR and TGF mechanics. Results:The results predict the dynamics of renal autoregulation on its blood pressure and flow,and the distributions are 88.5% in the cortex, 10.3% in the medulla, and 1.2% at papilla,respectively. The fluid flow and solute concentrations along the tubules and vasa recta are obtained. Conclusion:The present model could assess renal functions qualitatively and quantitatively and provide a methodological approach for clinical research.

SGLT2 inhibitor empagliflozin reduces renal growth and albuminuria in proportion to hyperglycemia and prevents glomerular hyperfiltration in diabetic Akita mice

Science.gov (United States)

Gerasimova, Maria; Rose, Michael A.; Masuda, Takahiro; Satriano, Joseph; Mayoux, Eric; Koepsell, Hermann; Thomson, Scott C.; Rieg, Timo

2013-01-01

Our previous work has shown that gene knockout of the sodium-glucose cotransporter SGLT2 modestly lowered blood glucose in streptozotocin-diabetic mice (BG; from 470 to 300 mg/dl) and prevented glomerular hyperfiltration but did not attenuate albuminuria or renal growth and inflammation. Here we determined effects of the SGLT2 inhibitor empagliflozin (300 mg/kg of diet for 15 wk; corresponding to 60–80 mg·kg−1·day−1) in type 1 diabetic Akita mice that, opposite to streptozotocin-diabetes, upregulate renal SGLT2 expression. Akita diabetes, empagliflozin, and Akita + empagliflozin similarly increased renal membrane SGLT2 expression (by 38–56%) and reduced the expression of SGLT1 (by 33–37%) vs. vehicle-treated wild-type controls (WT). The diabetes-induced changes in SGLT2/SGLT1 protein expression are expected to enhance the BG-lowering potential of SGLT2 inhibition, and empagliflozin strongly lowered BG in Akita (means of 187–237 vs. 517–535 mg/dl in vehicle group; 100–140 mg/dl in WT). Empagliflozin modestly reduced GFR in WT (250 vs. 306 μl/min) and completely prevented the diabetes-induced increase in glomerular filtration rate (GFR) (255 vs. 397 μl/min). Empagliflozin attenuated increases in kidney weight and urinary albumin/creatinine ratio in Akita in proportion to hyperglycemia. Empagliflozin did not increase urinary glucose/creatinine ratios in Akita, indicating the reduction in filtered glucose balanced the inhibition of glucose reabsorption. Empagliflozin attenuated/prevented the increase in systolic blood pressure, glomerular size, and molecular markers of kidney growth, inflammation, and gluconeogenesis in Akita. We propose that SGLT2 inhibition can lower GFR independent of reducing BG (consistent with the tubular hypothesis of diabetic glomerular hyperfiltration), while attenuation of albuminuria, kidney growth, and inflammation in the early diabetic kidney may mostly be secondary to lower BG. PMID:24226524

Steroid hormone release as well as renal water and electrolyte excretion of mice expressing PKB/SGK-resistant GSK3.

Science.gov (United States)

Boini, Krishna M; Bhandaru, Madhuri; Mack, Andreas; Lang, Florian

2008-09-01

Insulin and insulin-like growth factor (IGF1) participate in the regulation of renal electrolyte excretion. Insulin- and IGF1-dependent signaling includes phosphatidylinositide-3 (PI3)-kinase, phosphoinositide-dependent kinase PDK1 as well as protein kinase B (PKB) and serum and glucocorticoid inducible kinase (SGK) isoforms, which in turn phosphorylate and thus inhibit glycogen synthase kinase GSK3alpha,beta. Replacement of the serines in the PKB/SGK consensus sequences by alanine (gsk3 ( KI )) confers resistance of GSK3 to PKB/SGK. To explore the role of PKB/SGK-dependent inhibition of GSK3 in the regulation of water/electrolyte metabolism, mice carrying the PKB/SGK resistant mutant (gsk3 ( KI )) were compared to their wild-type littermates (gsk3 ( WT ) ). Body weight was similar in gsk3 ( KI ) and gsk3 ( WT ) mice. Plasma aldosterone at 10 A.M: . and corticosterone concentrations at 5 P.M: . were significantly lower, but 24-h urinary aldosterone was significantly higher, and corticosterone excretion tended to be higher in gsk3 ( KI ) than in gsk3 ( WT ) mice. Food and water intake, fecal excretion, glomerular filtration rate, urinary flow rate, urine osmolarity, as well as urinary Na+, K+, urea excretion were significantly larger, and plasma Na+, urea, but not K+ concentration, were significantly lower in gsk3 ( KI ) than in gsk3 ( WT ) mice. Body temperature was significantly higher in gsk3 ( KI ) than in gsk3 ( WT ) mice. When allowed to choose between tap water and saline, gsk3 ( WT ) mice drank more saline, whereas gsk3 ( KI ) mice drank similar large volumes of tap water and saline. During high-salt diet, urinary vasopressin excretion increased to significantly higher levels in gsk3 ( KI ) than in gsk3 ( WT ) mice. After water deprivation, body weight decreased faster in gsk3 ( KI ) than in gsk3 ( WT ) mice. Blood pressure, however, was significantly higher in gsk3 ( KI ) than in gsk3 ( WT ) mice. The observations disclose a role of PKB/SGK-dependent GSK3

The Effects of Renal Denervation on Renal Hemodynamics and Renal Vasculature in a Porcine Model.

Directory of Open Access Journals (Sweden)

Willemien L Verloop

Full Text Available Recently, the efficacy of renal denervation (RDN has been debated. It is discussed whether RDN is able to adequately target the renal nerves.We aimed to investigate how effective RDN was by means of functional hemodynamic measurements and nerve damage on histology.We performed hemodynamic measurements in both renal arteries of healthy pigs using a Doppler flow and pressure wire. Subsequently unilateral denervation was performed, followed by repeated bilateral hemodynamic measurements. Pigs were terminated directly after RDN or were followed for 3 weeks or 3 months after the procedure. After termination, both treated and control arteries were prepared for histology to evaluate vascular damage and nerve damage. Directly after RDN, resting renal blood flow tended to increase by 29±67% (P = 0.01. In contrast, renal resistance reserve increased from 1.74 (1.28 to 1.88 (1.17 (P = 0.02 during follow-up. Vascular histopathology showed that most nerves around the treated arteries were located outside the lesion areas (8±7 out of 55±25 (14% nerves per pig were observed within a lesion area. Subsequently, a correlation was noted between a more impaired adventitia and a reduction in renal resistance reserve (β: -0.33; P = 0.05 at three weeks of follow-up.Only a small minority of renal nerves was targeted after RDN. Furthermore, more severe adventitial damage was related to a reduction in renal resistance in the treated arteries at follow-up. These hemodynamic and histological observations may indicate that RDN did not sufficiently target the renal nerves. Potentially, this may explain the significant spread in the response after RDN.

The Effects of Renal Denervation on Renal Hemodynamics and Renal Vasculature in a Porcine Model

Science.gov (United States)

Verloop, Willemien L.; Hubens, Lisette E. G.; Spiering, Wilko; Doevendans, Pieter A.; Goldschmeding, Roel; Bleys, Ronald L. A. W.; Voskuil, Michiel

2015-01-01

Rationale Recently, the efficacy of renal denervation (RDN) has been debated. It is discussed whether RDN is able to adequately target the renal nerves. Objective We aimed to investigate how effective RDN was by means of functional hemodynamic measurements and nerve damage on histology. Methods and Results We performed hemodynamic measurements in both renal arteries of healthy pigs using a Doppler flow and pressure wire. Subsequently unilateral denervation was performed, followed by repeated bilateral hemodynamic measurements. Pigs were terminated directly after RDN or were followed for 3 weeks or 3 months after the procedure. After termination, both treated and control arteries were prepared for histology to evaluate vascular damage and nerve damage. Directly after RDN, resting renal blood flow tended to increase by 29±67% (P = 0.01). In contrast, renal resistance reserve increased from 1.74 (1.28) to 1.88 (1.17) (P = 0.02) during follow-up. Vascular histopathology showed that most nerves around the treated arteries were located outside the lesion areas (8±7 out of 55±25 (14%) nerves per pig were observed within a lesion area). Subsequently, a correlation was noted between a more impaired adventitia and a reduction in renal resistance reserve (β: -0.33; P = 0.05) at three weeks of follow-up. Conclusion Only a small minority of renal nerves was targeted after RDN. Furthermore, more severe adventitial damage was related to a reduction in renal resistance in the treated arteries at follow-up. These hemodynamic and histological observations may indicate that RDN did not sufficiently target the renal nerves. Potentially, this may explain the significant spread in the response after RDN. PMID:26587981

Renal pathological implications in type 2 diabetes mellitus patients with renal involvement.

Science.gov (United States)

Li, Li; Zhang, Xiuhui; Li, Zhicheng; Zhang, Rui; Guo, Ruikun; Yin, Qinghua; Yang, Lichuan; Yue, Rongzheng; Su, Baihai; Huang, Songmin; Xu, Huan; He, Cijiang; Liu, Fang

2017-01-01

To investigate the renal pathological implications in type 2 diabetes mellitus patients with renal involvement. A total of 328 type 2 diabetes mellitus (T2DM) patients with renal involvement who underwent a renal biopsy and received follow-up for at least one year were recruited in our study. The patients were divided into the diabetic nephropathy (DN), non-diabetic renal disease (NDRD), and NDRD superimposed on DN groups based on the pathological diagnosis. Renal outcomes were defined by the initiation of renal replacement therapy or doubling of the serum creatinine. Kaplan-Meier analysis was used to compare renal survival, and Cox proportional hazard analysis was used to determine the predictors of renal outcomes in the DN group. Renal biopsy findings revealed that 188 patients (57.32%) had pure DN, 121 patients (36.89%) had NDRD alone, and 19 patients (5.79%) had NDRD superimposed on DN. The most frequent subclassification of NDRD was membranous nephropathy (MN). Compared with the NDRD and NDRD superimposed on DN groups, patients with pure DN had poorer renal function and lower renal survival rates. In the DN group, the five-year renal survival rates of glomerular classes of I, IIa, IIb, III and IV were 100%, 84.62%, 60%, 47.5% and 33.33%, respectively. Multivariate Cox proportional hazard analysis showed that the glomerular lesions, proteinuria and serum creatinine were independent risk factors for renal outcomes, while interstitial fibrosis/inflammation and arteriolar hyalinosis were not independently associated with renal outcomes in the DN group. Making an accurate pathologic diagnosis by renal biopsy is crucial for diabetes mellitus (DM) patients with renal involvement. The findings of our present study indicated that patients with pure DN had poorer renal outcomes than patients with NDRD or NDRD superimposed on DN. The classification of glomerular lesions, proteinuria and serum creatinine were independent risk factors for renal outcomes in the DN group

Detection of acute renal allograft rejection by analysis of renal tissue proteomics in rat models of renal transplantation

Directory of Open Access Journals (Sweden)

Dai Yong

2008-01-01

Full Text Available At present, the diagnosis of renal allograft rejection requires a renal biopsy. Clinical management of renal transplant patients would be improved if rapid, noninvasive and reliable biomarkers of rejection were available. This study is designed to determine whether such protein biomarkers can be found in renal-graft tissue proteomic approach. Orthotopic kidney transplantations were performed using Fisher (F344 or Lewis rats as donors and Lewis rats as recipients. Hence, there were two groups of renal transplant models: one is allograft (from F344 to Lewis rats; another is syngrafts (from Lewis to Lewis rats serving as control. Renal tissues were collected 3, 7 and 14 days after transplantation. As many as 18 samples were analyzed by 2-D Electrophoresis and mass spectrometry (MALDI-TOF-TOF-MS. Eleven differentially expressed proteins were identified between groups. In conclusion, proteomic technology can detect renal tissue proteins associated with acute renal allograft rejection. Identification of these proteins as diagnostic markers for rejection in patients′ urine or sera may be useful and non-invasive, and these proteins might serve as novel therapeutic targets that also help to improve the understanding of mechanism of renal rejection.

Renal sympathetic denervation: MDCT evaluation of the renal arteries.

LENUS (Irish Health Repository)

Hutchinson, Barry D

2013-08-01

Percutaneous transluminal renal sympathetic denervation is a new treatment of refractory systemic hypertension. The purpose of this study was to assess the clinical utility of MDCT to evaluate the anatomic configuration of the renal arteries in the context of renal sympathetic denervation.

SGLT5 Reabsorbs Fructose in the Kidney but Its Deficiency Paradoxically Exacerbates Hepatic Steatosis Induced by Fructose

Science.gov (United States)

Fukuzawa, Taku; Fukazawa, Masanori; Ueda, Otoya; Shimada, Hideaki; Kito, Aki; Kakefuda, Mami; Kawase, Yosuke; Wada, Naoko A.; Goto, Chisato; Fukushima, Naoshi; Jishage, Kou-ichi; Honda, Kiyofumi; King, George L.; Kawabe, Yoshiki

2013-01-01

Although excessive fructose intake is epidemiologically linked with dyslipidemia, obesity, and diabetes, the mechanisms regulating plasma fructose are not well known. Cells transfected with sodium/glucose cotransporter 5 (SGLT5), which is expressed exclusively in the kidney, transport fructose in vitro; however, the physiological role of this transporter in fructose metabolism remains unclear. To determine whether SGLT5 functions as a fructose transporter in vivo, we established a line of mice lacking the gene encoding SGLT5. Sodium-dependent fructose uptake disappeared in renal brush border membrane vesicles from SGLT5-deficient mice, and the increased urinary fructose in SGLT5-deficient mice indicated that SGLT5 was the major fructose reabsorption transporter in the kidney. From this, we hypothesized that urinary fructose excretion induced by SGLT5 deficiency would ameliorate fructose-induced hepatic steatosis. To test this hypothesis we compared SGLT5-deficient mice with wild-type mice under conditions of long-term fructose consumption. Paradoxically, however, fructose-induced hepatic steatosis was exacerbated in the SGLT5-deficient mice, and the massive urinary fructose excretion was accompanied by reduced levels of plasma triglycerides and epididymal fat but fasting hyperinsulinemia compared with fructose-fed wild-type mice. There was no difference in food consumption, water intake, or plasma fructose between the two types of mice. No compensatory effect by other transporters reportedly involved in fructose uptake in the liver and kidney were indicated at the mRNA level. These surprising findings indicated a previously unrecognized link through SGLT5 between renal fructose reabsorption and hepatic lipid metabolism. PMID:23451068

Patients with gout differ from healthy subjects in renal response to changes in serum uric acid.

Science.gov (United States)

Liu, Sha; Perez-Ruiz, Fernando; Miner, Jeffrey N

2017-03-01

Our objectives were to determine whether a change in serum uric acid (sUA) resulted in a corresponding change in the fractional excretion of uric acid (FEUA) and whether the renal response was different in patients with gout versus healthy subjects. FEUA was calculated from previously published studies and four new phase I studies in healthy subjects and/or patients with gout before and after treatment to lower or raise sUA. Treatments included xanthine oxidase inhibitors to lower sUA as well as infusion of uric acid and provision of a high-purine diet to raise sUA. Plots were created of FEUA versus sUA before and after treatment. For the phase I studies, percent change in FEUA per mg/dL change in sUA was calculated separately for healthy subjects and patients with gout, and compared using Student's t test. Analysis of previously published data and the new phase I clinical data indicates that changing sUA by a non-renal mechanism leads to a change in FEUA. The magnitude of change is greater in subjects with higher baseline FEUA versus patients with gout. Healthy subjects excrete more urate than do patients with gout at physiological urate-filtered load; this difference disappears when the urate-filtered load is decreased to ∼5000mg/24hours. These observations are consistent with a less saturated urate reabsorption system in patients with gout versus healthy subjects, resulting in elevated retention of uric acid. Further investigation could lead to the discovery of mechanisms responsible for the etiology of hyperuricemia/gout. Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Relationship between renal cortex and parenchyma thickness and renal function: study with CT measurement

International Nuclear Information System (INIS)

Xu Yufeng; Tang Guangjian; Jiang Xuexiang

2006-01-01

Objective: To study the relationship between renal morphology and renal function, and to assess the value of CT as a criterion to grade renal function. Methods: Enhancement CT were performed in 89 patients with no local renal disease whose split renal glomerular filtration rates (GFR) were measured by renal dynamic imaging with 99 Tc m -DTPA. The 178 kidneys were divided into normal renal function, mild and severe renal impairment groups according to renal function. Differences between three groups respect to the mean thickness of renal cortex and parenchyma were assessed by ANOVA. Using Pearson's correlation test, the correlation between the renal cortex, parenchyma thicknesses and renal GFR were examined. The value of CT in predicting renal function was assessed by using ROC analysis. Results: The renal cortex thicknesses of normal renal function, mild and severe renal impairment groups were (5.9±1.1), (4.6± 1.1), and (3.3±1.0) mm respectively, and the renal parenchyma thicknesses were (26.3±4.2), (21.3±4.6), (16.2±4.6) mm. There were significant differences of renal cortex, parenchyma thicknesses between 3 groups (cortex F=54.78, P<0.01; parenehyma F=43.90, P<0.01). The thicknesses of renal cortex (r=0.752, P<0.01), parenchyma (r=0.738, P<0.01) had positive linear correlation with renal function. ROC analysis of the renal cortex thicknesses measured by CT in predicting mild and severe renal impairment showed that the Az was 0.860 and 0.905 respectively, whereas that of parenchyma was 0.868 and 0.884. Conclusion: The thicknesses of renal cortex, parenchyma measured by CT can reflect renal function. CT was a supplementary method to assess renal function. (authors)

Glomerular Filtration Rate Estimation in Renal and Non-Renal Solid Organ Transplantation

DEFF Research Database (Denmark)

Hornum, Mads; Feldt-Rasmussen, Bo

2017-01-01

Following transplantation (TX) of both renal and non-renal organs, a large proportion of patients have renal dysfunction. There are multiple causes for this. Chronic nephrotoxicity and high doses of calcineurin inhibitors are important factors. Preoperative and perioperative factors like...... or estimates of renal function in these patients, in order to accurately and safely dose immunosuppressive medication and perform and adjust the treatment and prophylaxis of renal dysfunction. This is a short overview and discussion of relevant studies and possible caveats of estimated glomerular filtration...... rate methods for use in renal and non-renal TX....

Superselective transcatheter renal arterial embolization for acute renal bleeding in patients with renal insufficiency: its clinical efficacy and safety

International Nuclear Information System (INIS)

Hu Tingyang; Zhou Bing; Yu Wenqiang; Luo Zuyan; Mao Yingmin; Chen Fanghong; Li Bo; Yuan Jianhua

2010-01-01

Objective: To discuss the clinical efficacy and complications of super selective renal arterial embolization in treating acute renal arterial bleeding in patients with renal insufficiency, and to evaluate the influence of the treatment on the renal function. Methods: During the period of January 2000 December 2009, super selective renal arterial embolization was performed in our institution for acute renal bleeding in 13 patients with renal insufficiency. The complete clinical and imaging materials of all patients were properly collected. The clinical effectiveness, the renal function, the extent of embolization and the complications were observed and the relationship between each other was analyzed. Results: The embolization procedure was successfully completed in all patients with a technical success rate of 100%. The mean embolized territory was 22% of a single kidney. Three days after the procedure, the hemoglobin level, hematocrit, blood pressure and heart rate were considerably improved in all patients. Compared to the corresponding preoperative data, all the differences were statistically significant (P 0.05), while the blood urea nitrogen was markedly decreased (P=0.011). Post embolization syndrome occurred in 5 patients and progressive aggravation of the renal function was observed in one patient, who had to receive hemodialysis finally. The embolized territory in patients occurring complications was larger than that in patients without occurring complications (U=1.500, P=0.006). Conclusion: Super selective renal arterial embolization is an effective and safe treatment for acute renal arterial bleeding in patients with renal insufficiency, the therapy will not significantly worsen the renal function. Appropriate and reasonable extent of embolization, as small as possible, is the key point for reducing the complications. (authors)

Detection of acute renal allograft rejection by analysis of Renal TissueProteomics in rat models of renal transplantation

International Nuclear Information System (INIS)

Dai, Y.; Lv, T.; Wang, K.; Li, D.; Huang, Y.; Liu, J.

2008-01-01

At present, the diagnosis of renal allograft rejection requires a renalbiopsy. Clinical management of renal transplant patients would be improved ifrapid, noninvasive and reliable biomarkers of rejection were available. Thisstudy is designed to determine whether such protein biomarkers can be foundin renal graft tissue proteomic approach. Orthotopic kidney transplantationswere performed using Fisher (F344) or Lewis rats as donors and Lewis rats asrecipients. Hence, there were two groups of renal transplant models: one isallograft (from F344 to Lewis rats); another is syngrafts (from Lewis toLewis rats) serving as control. Renal tissues were collected 3, 7 and 14 daysafter transplantation. As many 18 samples were analyzed by 2-DElectrophoresis and mass spectrometry (MALDI-TOF-TOF-MS). Elevendifferentially expressed proteins were identified between groups. Inconclusion, proteomic technology can detect renal tissue proteins associatedwith acute renal allograft rejection. Identification of these proteins asdiagnostic markers for rejection in patient's urine or sera may be useful andnon-invasive, and these proteins might serve as novel therapeutic targetsthat also help to improve the understanding of mechanisms of renal rejection.(author)

Anatomic Patterns of Renal Arterial Sympathetic Innervation: New Aspects for Renal Denervation.

Science.gov (United States)

Imnadze, Guram; Balzer, Stefan; Meyer, Baerbel; Neumann, Joerg; Krech, Rainer Horst; Thale, Joachim; Franz, Norbert; Warnecke, Henning; Awad, Khaled; Hayek, Salim S; Devireddy, Chandan

2016-12-01

Initial studies of catheter-based renal arterial sympathetic denervation to lower blood pressure in resistant hypertensive patients renewed interest in the sympathetic nervous system's role in the pathogenesis of hypertension. However, the SYMPLICITY HTN-3 study failed to meet its prespecified blood pressure lowering efficacy endpoint. To date, only a limited number of studies have described the microanatomy of renal nerves, of which, only two involve humans. Renal arteries were harvested from 15 cadavers from the Klinikum Osnabruck and Schuchtermann Klinik, Bad Rothenfelde. Each artery was divided longitudinally in equal thirds (proximal, middle, and distal), with each section then divided into equal superior, inferior, anterior, and posterior quadrants, which were then stained. Segments containing no renal nerves were given a score value = 0, 1-2 nerves with diameter 4 nerves or nerve diameter ≥600 µm a score = 3. A total of 22 renal arteries (9 right-sided, 13 left-sided) were suitable for examination. Overall, 691 sections of 5 mm thickness were prepared. Right renal arteries had significantly higher mean innervation grade (1.56 ± 0.85) compared to left renal arteries (1.09 ± 0.87) (P renal artery has significantly higher innervation scores than the left. The anterior and superior quadrants of the renal arteries scored higher in innervation than the posterior and inferior quadrants did. The distal third of the renal arteries are more innervated than the more proximal segments. These findings warrant further evaluation of the spatial innervation patterns of the renal artery in order to understand how it may enhance catheter-based renal arterial denervation procedural strategy and outcomes. The SYMPLICITY HTN-3 study dealt a blow to the idea of the catheter-based renal arterial sympathetic denervation. We investigated the location and patterns of periarterial renal nerves in cadaveric human renal arteries. To quantify the density of the

The 64-MSCT study of relationship between renal corticomedullary differentiation, contrast between renal cortex and medulla, renal cortex and medulla CT peak value with the single renal function in hydronephrotic kidney

International Nuclear Information System (INIS)

Wang Yunhua; Hou Weiwei; Liu Ruihong; He Jianjun; Zhi Ke

2009-01-01

Objective: To study 64-MSCT perfusion imaging features about renal corticomedullary differentiation, contrast between renal cortex and medulla (CMC), renal cortex and medulla CT peak value in normal and hydronephrotic kidneys, and to explore the relationship between them and the unilateral renal function. Methods: Thirty-six patients with obstructive nephrohydrosis underwent 64-MSCT perfusion scanning. The split renal glomerular filtration rates (GFR) of their kidneys were measured by SPECT renal dynamic imaging. The 72 kidneys were divided into groups of normal renal function group, mild and severe renal impairment groups according to GFR. Renal corticomedullary differentiation on CT images was graded as clear, obscure, part clear. The CT intensity of cortex and medulla was measured in order to calculate contrast between renal cortex and medulla (CMC). Using Pearson correlation test, the correlation between them and renal GFR were examined. Results: (1) In the 24 kidneys of normal group, all kidneys showed clear CMD. In the 21 kidneys of mild renal impairment group, 14 kidneys showed clear CMD, 2 showed obscure CMD and 5 showed part clear of CMD. In the 27 kidneys of severe renal impairment group, 7 kidneys showed clear CMD, 5 showed obscure CMD and 15 showed part clear of CMD. (2)The CMC of normal group was 0.62 ± 0.20, while it was 0.52 ± 0.14 and 0.37 ± 0.11 for mild renal impairment group and severe renal impairment group CMC respectively. The CMC had positive linear correlation with GFR (r=0.536,P<0.05). (3) The renal cortex and medulla CT peak value of normal group were (133 ± 22) and (104 ± 16) HU; The renal cortex and medulla CT peak value of mild renal impairment group were (91 ± 29) and (76 ± 25) HU; The renal cortex and medulla CT peak value of severe renal impairment group were (68 ± 24) and (57 ± 21) HU(F=42.76 and 32.68,P<0.05). The renal cortex and medulla CT peak value had positive linear correlation with GFR (r=0.672 and 0.623, P<0

The intrarenal distribution of 125I-albumin in the syrian hamster

International Nuclear Information System (INIS)

Moeller, P.

1977-01-01

The intrarenal distribution of radioiodinated human serum albumin ( 125 RISA) after intravenous injection was studied in Syrian hamsters by scintillation counting and frozen section autoradiogrpahy. After 15, 30, and 60 min the virtual plasma albumin space in the renal cortex of the hamster represented 6.49, 7.13, and 8.06% respectively of the kidney tissue volume. From the cortex to the renal papilla the albumin space increased to about 30% of the tissue volume. In comparison to this the albumin space in the renal cortex of the rat was about 20%, and in the renal papilla about 33% (11). Frozen section autoradiography indicated that the distribution of radioalbumin in the renal cortex if the Syrian hamster is limited mainly to the kidney vessels, being especially noticeable in the glomerular capillaries. Toward the papilla increasingly greater (mainly extratubular) activity could be observed not only intravascularly but also interstitially. In the cortex of the rat kidney, on the other hand, radioactive albumin was accumulated (probably by filtration and reabsorption) predominantly in the proximal tubular epithelium. Within 30 min the kidneys of the rat excreted more than 10 times as much 125 I than the hamster kidneys. These results (substantially less cortical accumulation and urinary excretion of radioalbumin in the Syrian hamster) indicate that, in contrast to the rat, obviously much less albumin is filtered (and then accumulated by proximal reabsorption) by the Syrian hamster glomeruli. This suggests that the Syrian hamster kidney is more suitable than the rat kidney for determining the interstitial, cortical, albumin space. (orig./AJ) [de

Multiple Renal Artery Pseudoaneurysms in Patients Undergoing Renal Artery Embolization Following Partial Nephrectomy: Correlation with RENAL Nephrometry Scores

International Nuclear Information System (INIS)

Gupta, Nakul; Patel, Anish; Ensor, Joe; Ahrar, Kamran; Ahrar, Judy; Tam, Alda; Odisio, Bruno; Huang, Stephen; Murthy, Ravi; Mahvash, Armeen; Avritscher, Rony; McRae, Stephen; Sabir, Sharjeel; Wallace, Michael; Matin, Surena; Gupta, Sanjay

2017-01-01

PurposeTo describe the incidence of multiple renal artery pseudoaneurysms (PSA) in patients referred for renal artery embolization following partial nephrectomy and to study its relationship to RENAL nephrometry scores.Materials and MethodsThe medical records of 25 patients referred for renal artery embolization after partial nephrectomy were retrospectively reviewed for the following parameters: size and number of tumors, RENAL nephrometry scores, angiographic abnormalities, technical and clinical outcomes, and estimated glomerular filtration rates (eGFRs) after embolization.ResultsTwenty-four patients had primary renal tumors, while 1 patient had a pancreatic tumor invading the kidney. Multiple tumors were resected in 4 patients. Most patients (92 %) were symptomatic, presenting with gross hematuria, flank pain, or both. Angiography revealed PSA with (n = 5) or without (n = 20) AV fistulae. Sixteen patients (64 %) had multiple PSA involving multiple renal vessels. Higher RENAL nephrometry scores were associated with an increasing likelihood of multiple PSA. Multiple vessels were embolized in 14 patients (56 %). Clinical success was achieved after one (n = 22) or two (n = 3) embolization sessions in all patients. Post-embolization eGFR values at different time points after embolization were not significantly different from the post-operative eGFR.ConclusionA majority of patients requiring renal artery embolization following partial nephrectomy have multiple pseudoaneurysms, often requiring selective embolization of multiple vessels. Higher RENAL nephrometry score is associated with an increasing likelihood of multiple pseudoaneurysms. We found transarterial embolization to be a safe and effective treatment option with no long-term adverse effect on renal function in all but one patient with a solitary kidney.

Multiple Renal Artery Pseudoaneurysms in Patients Undergoing Renal Artery Embolization Following Partial Nephrectomy: Correlation with RENAL Nephrometry Scores

Energy Technology Data Exchange (ETDEWEB)

Gupta, Nakul [Houston Methodist Hospital (United States); Patel, Anish [The University of Texas Southwestern Medical Center (United States); Ensor, Joe [Houston Methodist Research Institute, The Houston Methodist Cancer Center (United States); Ahrar, Kamran; Ahrar, Judy; Tam, Alda; Odisio, Bruno; Huang, Stephen; Murthy, Ravi; Mahvash, Armeen; Avritscher, Rony; McRae, Stephen; Sabir, Sharjeel; Wallace, Michael [The University of Texas MD Anderson Cancer Center, Department of Interventional Radiology (United States); Matin, Surena [The University of Texas MD Anderson Cancer Center, Department of Urology (United States); Gupta, Sanjay, E-mail: sgupta@mdanderson.org [The University of Texas MD Anderson Cancer Center, Department of Interventional Radiology (United States)

2017-02-15

PurposeTo describe the incidence of multiple renal artery pseudoaneurysms (PSA) in patients referred for renal artery embolization following partial nephrectomy and to study its relationship to RENAL nephrometry scores.Materials and MethodsThe medical records of 25 patients referred for renal artery embolization after partial nephrectomy were retrospectively reviewed for the following parameters: size and number of tumors, RENAL nephrometry scores, angiographic abnormalities, technical and clinical outcomes, and estimated glomerular filtration rates (eGFRs) after embolization.ResultsTwenty-four patients had primary renal tumors, while 1 patient had a pancreatic tumor invading the kidney. Multiple tumors were resected in 4 patients. Most patients (92 %) were symptomatic, presenting with gross hematuria, flank pain, or both. Angiography revealed PSA with (n = 5) or without (n = 20) AV fistulae. Sixteen patients (64 %) had multiple PSA involving multiple renal vessels. Higher RENAL nephrometry scores were associated with an increasing likelihood of multiple PSA. Multiple vessels were embolized in 14 patients (56 %). Clinical success was achieved after one (n = 22) or two (n = 3) embolization sessions in all patients. Post-embolization eGFR values at different time points after embolization were not significantly different from the post-operative eGFR.ConclusionA majority of patients requiring renal artery embolization following partial nephrectomy have multiple pseudoaneurysms, often requiring selective embolization of multiple vessels. Higher RENAL nephrometry score is associated with an increasing likelihood of multiple pseudoaneurysms. We found transarterial embolization to be a safe and effective treatment option with no long-term adverse effect on renal function in all but one patient with a solitary kidney.

Impaired Urine Dilution Capability in HIV Stable Patients

Directory of Open Access Journals (Sweden)

Waldo H. Belloso

2014-01-01

Full Text Available Renal disease is a well-recognized complication among patients with HIV infection. Viral infection itself and the use of some antiretroviral drugs contribute to this condition. The thick ascending limb of Henle’s loop (TALH is the tubule segment where free water clearance is generated, determining along with glomerular filtration rate the kidney’s ability to dilute urine. Objective. We analyzed the function of the proximal tubule and TALH in patients with HIV infection receiving or not tenofovir-containing antiretroviral treatment in comparison with healthy seronegative controls, by applying a tubular physiological test, hyposaline infusion test (Chaimowitz’ test. Material & Methods. Chaimowitz’ test was performed on 20 HIV positive volunteers who had normal renal functional parameters. The control group included 10 healthy volunteers. Results. After the test, both HIV groups had a significant reduction of serum sodium and osmolarity compared with the control group. Free water clearance was lower and urine osmolarity was higher in both HIV+ groups. Proximal tubular function was normal in both studied groups. Conclusion. The present study documented that proximal tubule sodium reabsorption was preserved while free water clearance and maximal urine dilution capability were reduced in stable HIV patients treated or not with tenofovir.

Regulation of transport in the connecting tubule and cortical collecting duct

Science.gov (United States)

Staruschenko, Alexander

2012-01-01

The central goal of this overview article is to summarize recent findings in renal epithelial transport, focusing chiefly on the connecting tubule (CNT) and the cortical collecting duct (CCD). Mammalian CCD and CNT are involved in fine tuning of electrolyte and fluid balance through reabsorption and secretion. Specific transporters and channels mediate vectorial movements of water and solutes in these segments. Although only a small percent of the glomerular filtrate reaches the CNT and CCD, these segments are critical for water and electrolyte homeostasis since several hormones, e.g. aldosterone and arginine vasopressin, exert their main effects in these nephron sites. Importantly, hormones regulate the function of the entire nephron and kidney by affecting channels and transporters in the CNT and CCD. Knowledge about the physiological and pathophysiological regulation of transport in the CNT and CCD and particular roles of specific channels/transporters has increased tremendously over the last two decades. Recent studies shed new light on several key questions concerning the regulation of renal transport. Precise distribution patterns of transport proteins in the CCD and CNT will be reviewed, and their physiological roles and mechanisms mediating ion transport in these segments will be also covered. Special emphasis will be given to pathophysiological conditions appearing as a result of abnormalities in renal transport in the CNT and CCD. PMID:23227301

Active lithium transport by rat renal proximal tubule: a micropuncture study

DEFF Research Database (Denmark)

Leyssac, P P; Frederiksen, O; Holstein-Rathlou, N H

1994-01-01

We tested the hypothesis that proximal tubular Li+ reabsorption is due to passive transport. Clearances of [14C]inulin (CIn) and Li+ (CLi), proximal transepithelial electrical potential difference (PD), and tubular fluid-to-plasma Li+ concentration ratios [(TF/P)Li] were measured in anesthetized ...

The renal quantitative scintillation camera study for determination of renal function

International Nuclear Information System (INIS)

Thompson, I.M. Jr.; Boineau, F.G.; Evans, B.B.; Schlegel, J.U.

1983-01-01

The renal quantitative scintillation camera study assesses glomerular filtration rate and effective renal plasma flow based upon renal uptake of 99mtechnetium-iron ascorbate and 131iodine-hippuran, respectively. The method was compared to inulin, para-aminohippuric acid and creatinine clearance studies in 7 normal subjects and 9 patients with various degrees of reduced renal function. The reproducibility of the technique was determined in 15 randomly selected pediatric patients. The values of glomerular filtration rate and effective renal plasma flow were not significantly different from those of inulin and para-aminohippuric acid studies. The reproducibility of the technique was comparable to that of inulin and para-aminohippuric acid studies. Patient acceptance of the technique is excellent and the cost is minimal. Renal morphology and excretory dynamics also are demonstrated. The technique is advocated as a clinical measure of renal function

Inhibiting aerobic glycolysis suppresses renal interstitial fibroblast activation and renal fibrosis.

Science.gov (United States)

Ding, Hao; Jiang, Lei; Xu, Jing; Bai, Feng; Zhou, Yang; Yuan, Qi; Luo, Jing; Zen, Ke; Yang, Junwei

2017-09-01

Chronic kidney diseases generally lead to renal fibrosis. Despite great progress having been made in identifying molecular mediators of fibrosis, the mechanism that governs renal fibrosis remains unclear, and so far no effective therapeutic antifibrosis strategy is available. Here we demonstrated that a switch of metabolism from oxidative phosphorylation to aerobic glycolysis (Warburg effect) in renal fibroblasts was the primary feature of fibroblast activation during renal fibrosis and that suppressing renal fibroblast aerobic glycolysis could significantly reduce renal fibrosis. Both gene and protein assay showed that the expression of glycolysis enzymes was upregulated in mouse kidneys with unilateral ureter obstruction (UUO) surgery or in transforming growth factor-β1 (TGF-β1)-treated renal interstitial fibroblasts. Aerobic glycolysis flux, indicated by glucose uptake and lactate production, was increased in mouse kidney with UUO nephropathy or TGF-β1-treated renal interstitial fibroblasts and positively correlated with fibrosis process. In line with this, we found that increasing aerobic glycolysis can remarkably induce myofibroblast activation while aerobic glycolysis inhibitors shikonin and 2-deoxyglucose attenuate UUO-induced mouse renal fibrosis and TGF-β1-stimulated myofibroblast activation. Furthermore, mechanistic study indicated that shikonin inhibits renal aerobic glycolysis via reducing phosphorylation of pyruvate kinase type M2, a rate-limiting glycolytic enzyme associated with cell reliance on aerobic glycolysis. In conclusion, our findings demonstrate the critical role of aerobic glycolysis in renal fibrosis and support treatment with aerobic glycolysis inhibitors as a potential antifibrotic strategy. Copyright © 2017 the American Physiological Society.

RENAL CRYOABLATION

Directory of Open Access Journals (Sweden)

A. V. Govorov

2012-01-01

Full Text Available Renal cryoablation is an alternative minimally-invasive method of treatment for localized renal cell carcinoma. The main advantages of this methodology include visualization of the tumor and the forming of "ice ball" in real time, fewer complications compared with other methods of treatment of renal cell carcinoma, as well as the possibility of conducting cryotherapy in patients with concomitant pathology. Compared with other ablative technologies cryoablation has a low rate of repeat sessions and good intermediate oncological results. The studies of long-term oncological and functional results of renal cryoablation are presently under way.

Renal artery pulsatility index and renal volume: Normal fetuses versus growth-retarded fetuses

International Nuclear Information System (INIS)

Lee, Kyung Soon; Woo, Bock Hi

2001-01-01

To evaluate the blood flow velocity waveform of the renal artery and renal volume of growth-retarded fetuses and to compare them with those of normal fetuses. Pulsatility index of the renal artery and renal volume measured by three-dimensional ultrasonography were obtained from seventy eight normal fetuses at the gestational age from twenty five to thirty nine weeks and eighteen intrauterine growth retarded fetuses whose weight was below ten percentile at birth. We studied changes of the pulsatility index of the renal artery and renal volume according to the gestational age and compared with those of growth-retarded fetuses. Pulsatility index (PI) of the fetal renal artery decreased throughout the gestational period (r=0.703, p<0.0001). In growth-retarded fetuses, despite of abnormal doppler velocity waveform of the middle cerebral artery, which was showing fetal hypoxia, the renal PI was not increased significantly. The fetal renal volume increased throughout the gestational period (r=0.834, p<0.0001) whereas in growth-retarded fetuses, all renal volume was below fifth percentile of normal fetuses. In growth-retarded fetuses, fetal renal volume was decreased significantly without change of the renal vascular flow. Therefore, the fetal renal volume measured by three-dimensional ultrasonography may be a helpful parameter in the diagnosis of growth-retarded fetuses.

Renal artery pulsatility index and renal volume: Normal fetuses versus growth-retarded fetuses

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyung Soon; Woo, Bock Hi [Ewha Womans University College of Medicine, Seoul (Korea, Republic of)

2001-06-15

To evaluate the blood flow velocity waveform of the renal artery and renal volume of growth-retarded fetuses and to compare them with those of normal fetuses. Pulsatility index of the renal artery and renal volume measured by three-dimensional ultrasonography were obtained from seventy eight normal fetuses at the gestational age from twenty five to thirty nine weeks and eighteen intrauterine growth retarded fetuses whose weight was below ten percentile at birth. We studied changes of the pulsatility index of the renal artery and renal volume according to the gestational age and compared with those of growth-retarded fetuses. Pulsatility index (PI) of the fetal renal artery decreased throughout the gestational period (r=0.703, p<0.0001). In growth-retarded fetuses, despite of abnormal doppler velocity waveform of the middle cerebral artery, which was showing fetal hypoxia, the renal PI was not increased significantly. The fetal renal volume increased throughout the gestational period (r=0.834, p<0.0001) whereas in growth-retarded fetuses, all renal volume was below fifth percentile of normal fetuses. In growth-retarded fetuses, fetal renal volume was decreased significantly without change of the renal vascular flow. Therefore, the fetal renal volume measured by three-dimensional ultrasonography may be a helpful parameter in the diagnosis of growth-retarded fetuses.

Obesity and renal hemodynamics

NARCIS (Netherlands)

Bosma, R. J.; Krikken, J. A.; van der Heide, J. J. Homan; de Jong, P. E.; Navis, G. J.

2006-01-01

Obesity is a risk factor for renal damage in native kidney disease and in renal transplant recipients. Obesity is associated with several renal risk factors such as hypertension and diabetes that may convey renal risk, but obesity is also associated with an unfavorable renal hemodynamic profile

Does the presence of accessory renal arteries affect the efficacy of renal denervation?

Science.gov (United States)

Id, Dani; Kaltenbach, Benjamin; Bertog, Stefan C; Hornung, Marius; Hofmann, Ilona; Vaskelyte, Laura; Sievert, Horst

2013-10-01

This study sought to assess the efficacy of catheter-based renal sympathetic denervation in patients with accessory renal arteries and to compare the blood pressure (BP)-lowering effect with that observed in patients with bilateral single renal arteries after renal denervation. Catheter-based renal sympathetic denervation causes significant BP reductions in patients with resistant hypertension. Seventy-four patients were included in this study. Patients were assigned to 2 main groups: a bilateral single renal arteries group I (n = 54) and an accessory renal arteries group II (n = 20). Group II consisted of 9 patients whose accessory renal arteries were all denervated (group IIa), and 11 patients whose accessory renal arteries were not, or only incompletely, denervated (group IIb). The primary endpoint was the change in office systolic BP after 6 months. The procedure was successful in all patients. Group I: mean BP at baseline was 166.2/89.4 ± 20.5/14.6 mm Hg and decreased by -16.6 (p renal denervation in patients with accessory renal arteries is less pronounced than in patients with bilateral single renal arteries. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Radiopharmaceuticals for renal studies

International Nuclear Information System (INIS)

Verdera, Silvia

1994-01-01

Between the diagnostic techniques using radiopharmaceuticals in nuclear medicine it find renal studies.A brief description about renal glomerular filtration(GFR) and reliability renal plasma flux (ERPF),renal blood flux measurement agents (RBF),renal scintillation agents and radiation dose estimates by organ physiology was given in this study.tabs

Glomerular Filtration Rate Estimation in Renal and Non-Renal Solid Organ Transplantation

DEFF Research Database (Denmark)

Hornum, Mads; Feldt-Rasmussen, Bo

2017-01-01

Following transplantation (TX) of both renal and non-renal organs, a large proportion of patients have renal dysfunction. There are multiple causes for this. Chronic nephrotoxicity and high doses of calcineurin inhibitors are important factors. Preoperative and perioperative factors like hyperten......Following transplantation (TX) of both renal and non-renal organs, a large proportion of patients have renal dysfunction. There are multiple causes for this. Chronic nephrotoxicity and high doses of calcineurin inhibitors are important factors. Preoperative and perioperative factors like...... hypertension, hypotension, drugs and infections may play a causative role as well. Organ-specific causes include hepatorenal syndrome, cirrhosis, low cardiac function, low respiratory function and diabetes developed both before and after TX. It is important to be able to perform precise and valid measurements...... rate methods for use in renal and non-renal TX....

Treatment of non-neoplastic renal hemorrhage with segmental embolization of renal artery

International Nuclear Information System (INIS)

Zhu Bing

2007-01-01

Objective: To explore the value of segmental embolization of renal artery in dealing with non- neoplastic renal hemorrhage. Methods: Four cases of non-neoplastic hemorrhage, including 2 with bleeding after renal acupuncture biopsy, 2 with bleeding after nephrolithotomy and 1 with congenital renal arteriovenous malformation, were treated with superselective segmental embolization of renal artery. 2 were embolized with coil, 1 with alcohol plus coil and 1 with PVA parcels. Results: Hematuria disappeared in 1-3 days. There was no recurrence in 7-45 months follow up and no complications induced by embolization. Conclusion: It is a safe and reliable therapy to treat non-neoplastic renal hemorrhage with segmental embolization of renal artery. (authors)

Pharmacokinetics, pharmacodynamics, and tolerability of verinurad, a selective uric acid reabsorption inhibitor, in healthy adult male subjects

Directory of Open Access Journals (Sweden)

Shen Z

2017-07-01

Full Text Available Zancong Shen,1 Michael Gillen,2 Jeffrey N Miner,1 Gail Bucci,1 David M Wilson,1 Jesse W Hall1 1Ardea Biosciences, Inc., San Diego, CA, 2AstraZeneca, Gaithersburg, MD, USA Purpose: Verinurad (RDEA3170 is a selective uric acid reabsorption inhibitor in clinical development for the treatment of gout and asymptomatic hyperuricemia. The aim of this study was to evaluate the pharmacokinetics, pharmacodynamics, and tolerability of verinurad in healthy adult males.Subjects and methods: This was a Phase I, randomized, double-blind, placebo-controlled, single and multiple ascending dose study. Panels of eight male subjects received a single oral dose of verinurad or placebo in either a fasted or fed state; panels of 10–12 male subjects received ascending doses of once-daily verinurad or placebo in a fasted state for 10 days. Serial blood and urine samples were assayed for verinurad and uric acid. Safety was assessed by adverse event (AE reports, laboratory tests, vital signs, and electrocardiograms (ECGs.Results: A total of 81 adult males completed the study. Following single doses of verinurad, maximum observed plasma concentration (Cmax and area under the plasma concentration–time curve (AUC increased in a dose-proportional manner; Cmax occurred at 0.5–0.75 hours and 1.25 hours in the fasted and fed states, respectively. Food decreased AUC by 23% and Cmax by 37%-53%. There was a modest accumulation of verinurad following multiple daily doses. Verinurad reduced serum urate levels by up to 62% (40 mg, single dose and 61% (10 mg, multiple dose. The increase in urinary excretion of uric acid was greatest in the first 6 hours after dosing and was still evident ≥24 hours for verinurad doses ≥2 mg. Verinurad was well tolerated at all doses. No serious AEs, severe AEs, discontinuations due to AEs, or clinically significant laboratory or ECG abnormalities were reported.Conclusion: Single and multiple doses of verinurad were well tolerated

Bilateral renal artery variation

OpenAIRE

Üçerler, Hülya; Üzüm, Yusuf; İkiz, Z. Aslı Aktan

2014-01-01

Each kidney is supplied by a single renal artery, although renal artery variations are common. Variations of the renal arteryhave become important with the increasing number of renal transplantations. Numerous studies describe variations in renalartery anatomy. Especially the left renal artery is among the most critical arterial variations, because it is the referred side forresecting the donor kidney. During routine dissection in a formalin fixed male cadaver, we have found a bilateral renal...

[Aortic dissection spread to the renal arteries: role of renal volumetry after angioplasty].

Science.gov (United States)

Vautrin, E; Thony, F; Chavanon, O; Hannachi, I; Barone-Rochette, G; Pierre, H; Baguet, J-P

2012-06-01

Type A or B aortic dissection can extend to renal arteries, causing a renal ischemia which treatment is usually endovascular. The aim of our study is to show the interest of the renal volumetry in the follow-up of these patients. Twenty-two patients (16 men, mean age 63.4±11.8years, BMI 25.2±3.4kg/m(2)) with a type A or B aortic dissection spread to one or to both renal arteries and followed at Grenoble university hospital were consecutively included. All patients underwent renal angiography with aorto-renal pressure gradients measurements and follow-up by renal volumetry (scanner Siemens(®)). A renal ischemia was defined by a decrease of 20% or more of the volumetry. Sixteen patients (73%) were hypertensive before the aortic dissection among which ten (62%) were treated. Eight patients (36%) have a significant renal pressure gradient among which five (62%) underwent renal endovascular therapy. The renal volumetry of these five patients remained unchanged while six of 17 patients (36%) without angioplasty have a decreasing volumetry. Renal volumetry appeared an effective and attractive option for the follow-up of the patients with aortic dissection spread to the renal arteries. These results should be taken into account to put the indication of an endovascular treatment. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

BILATERAL DUPLICATION OF RENAL ARTERIES

OpenAIRE

Prajkta A Thete; Mehera Bhoir; M.V.Ambiye

2014-01-01

Routine dissection of a male cadaver revealed the presence of bilateral double renal arteries. On the right side the accessory renal artery originated from the abdominal aorta just above the main renal artery. On the left side the accessory renal artery originated from the abdominal aorta about 1 cm above the main renal artery. Knowledge of the variations of renal vascular anatomy has importance in exploration and treatment of renal trauma, renal transplantation, renal artery embolization, su...

Computed tomography of renal cell carcinoma in patients with terminal renal impairment

International Nuclear Information System (INIS)

Ferda, Jiri; Hora, Milan; Hes, Ondrej; Reischig, Tomas; Kreuzberg, Boris; Mirka, Hynek; Ferdova, Eva; Ohlidalova, Kristyna; Baxa, Jan; Urge, Tomas

2007-01-01

Purpose: An increased incidence of renal tumors has been observed in patients with end-stage-renal-disease (ESRD). The very strong association with acquired renal cystic disease (ACRD) and increased incidence of the renal tumors (conventional renal cell carcinoma (CRCC), papillary renal cell carcinoma (PRCC) or papillary renal cell adenoma (PRCA)) was reported. This study discusses the role of computed tomography (CT) in detecting renal tumors in patients with renal impairment: pre-dialysis, those receiving dialysis or with renal allograft transplants. Materials and methods: Ten patients (nine male, one female) with renal cell tumors were enrolled into a retrospective study; two were new dialysis patients, three on long-term dialysis, and five were renal transplant recipients with history of dialysis. All patients underwent helical CT, a total of 11 procedures were performed. Sixteen-row detector system was used five times, and a 64-row detector system for the six examinations. All patients underwent nephrectomy of kidney with suspected tumor, 15 nephrectomies were performed, and 1 kidney was assessed during autopsy. CT findings were compared with macroscopic and microscopic assessments of the kidney specimen in 16 cases. Results: Very advanced renal parenchyma atrophy with small cysts corresponding to ESRD was found in nine patients, chronic pyelonephritis in remained one. A spontaneously ruptured tumor was detected incidentally in one case, patient died 2 years later. In the present study, 6.25% (1/16) were multiple PRCA, 12.5% (2/16) were solitary PRCC, 12.5% tumors (2/16) were solitary conventional renal cell carcinomas (CRCC's), 12.5% tumors (2/16) were multiple conventional renal cell carcinomas (CRCC's), 25% (4/16) were CRCC's combined with multiple papillary renal cell carcinomas with adenomas (PRCC's and PRCA's), and 25% (4/16) of the tumors were multiple PRCC's combined with PRCA's without coexisting CRCC's. Bilateral renal tumors were found in our study

Traumatic renal infarction

International Nuclear Information System (INIS)

Yashiro, Naobumi; Ohtomo, Kuni; Kokubo, Takashi; Itai, Yuji; Iio, Masahiro

1986-01-01

Four cases of traumatic renal artery occlusion were described and illustrated. In two cases, direct blows to the abdomen compressed the renal artery against the vertebral column. Clinically, they were severely injured with macroscopic hematuria. Aortograms showed abrupt truncation of renal arteries. In the other two, rapid deceleration caused sudden displacement of the kidney producing an intimal tear with resultant thrombosis. Although they showed little injury without macrohematuria, aortograms revealed tapered occlusion of renal arteries. One of them developed hypertension. ''Rim sign'' of post-contrast CT and hypertension resulted from traumatic renal artery occlusion were reviewed. (author)

Imaging chronic renal disease and renal transplant in children

International Nuclear Information System (INIS)

Carmichael, Jim; Easty, Marina

2010-01-01

At Great Ormond Street Hospital we have the highest number of paediatric renal transplant patients in Europe, taking cases from across the United Kingdom and abroad. Our caseload includes many children with rare complicating medical problems and chronic renal failure related morbidity. This review aims to provide an overview of our experience of imaging children with chronic renal failure and transplants. (orig.)

High maternal sodium intake alters sex-specific renal renin-angiotensin system components in newborn Wistar offspring.

Science.gov (United States)

Maia, D R R; Lopes, K L; Heimann, J C; Furukawa, L N S

2016-01-28

This study aimed to evaluate the systemic and renal renin-angiotensin-aldosterone system (RAAS) at birth in male and female offspring and in mothers fed a high sodium diet (HSD) before and during gestation. Female Wistar rats were fed a HSD (8.0% NaCl) or a normal sodium diet (1.3% NaCl) from 8 weeks of age until delivery of their first litter. Maternal body weight, tail blood pressure, and food and water intake were evaluated. The litter sizes were assessed, and the body and kidney weights of the offspring were measured. Both mothers and offspring were euthanized immediately following the birth of the pups to evaluate plasma renin activity (PRA), renal renin content (RRC), renal angiotensin-converting enzyme (ACE) activity, renal angiotensin (Ang) II content, serum aldosterone (ALDO) levels, and renal cortical and medullary renin messenger RNA expression. In mothers in the HSD group, water intake and kidney mass were higher, whereas renal ACE activity, Ang II, PRA, ALDO and RRC were decreased. In the offspring of HSD-fed dams, the body and kidney mass were lower in both genders, renal ACE activity was lower in females and renal Ang II was lower in males. PRA, RRC, renin gene expression and ALDO levels did not differ between the groups of offspring. The data presented herein showed that a maternal HSD during pregnancy induces low birth weight and a sex-specific response in the RAAS in offspring.

Renal sodium-glucose cotransporter inhibition in the management of type 2 diabetes mellitus

Science.gov (United States)

Abdul-Ghani, Muhammad A.; Norton, Luke

2015-01-01

Hyperglycemia is the primary factor responsible for the microvascular, and to a lesser extent macrovascular, complications of diabetes. Despite this well-established relationship, approximately half of all type 2 diabetic patients in the US have a hemoglobin A1c (HbA1c) ≥7.0%. This is associated in part with the side effects, i.e., weight gain and hypoglycemia, of currently available antidiabetic agents and in part with the failure to utilize medications that reverse the basic pathophysiological defects present in patients with type 2 diabetes. The kidney has been shown to play a central role in the development of hyperglycemia by excessive production of glucose throughout the sleeping hours and enhanced reabsorption of filtered glucose by the renal tubules secondary to an increase in the threshold at which glucose spills into the urine. Recently, a new class of antidiabetic agents, the sodium-glucose cotransporter 2 (SGLT2) inhibitors, has been developed and approved for the treatment of patients with type 2 diabetes. In this review, we examine their mechanism of action, efficacy, safety, and place in the therapeutic armamentarium. Since the SGLT2 inhibitors have a unique mode of action that differs from all other oral and injectable antidiabetic agents, they can be used at all stages of the disease and in combination with all other antidiabetic medications. PMID:26354881

Radionuclide evaluation of renal transplants

International Nuclear Information System (INIS)

Yang Hong; Zhao Deshan

2000-01-01

Radionuclide renal imaging and plasma clearance methods can quickly quantitate renal blood flow and function in renal transplants. They can diagnose acute tubular necrosis and rejection, renal scar, surgical complications such as urine leaks, obstruction and renal artery stenosis after renal transplants. At the same time they can assess the therapy effect of renal transplant complications and can also predict renal transplant survival from early post-operative function studies

Rapid redistribution and inhibition of renal sodium transporters during acute pressure natriuresis

DEFF Research Database (Denmark)

Zhang, Y; Mircheff, A K; Hensley, C B

1996-01-01

and basolateral Na+ pumps to internal membranes. Arterial pressure was increased 50 mmHg by constricting various arteries. We also tested whether transporter internalization occurred when PT Na+ reabsorption was inhibited with the carbonic anhydrase inhibitor benzolamide. Five minutes after initiating either...

Salivary markers in patients with chronic renal failure.

Science.gov (United States)

Pallos, Debora; Leão, Mariella V P; Togeiro, Fernanda C F B; Alegre, Larissa; Ricardo, Lucilene Hernandes; Perozini, Caroline; Ruivo, Gilson Fernandes

2015-12-01

Chronic renal failure (CRF) is a progressive loss of renal function over a period of months or years. The major function of the kidneys is the removal of metabolic waste products, electrolytes and water. When this function is impaired, systemic changes, oral complications and alterations in salivary composition may occur. This study aimed to compare the levels of immunological and inflammatory components in the saliva samples from patients that undergo to hemodialysis treatment (HD), without HD and control. This study evaluated IgA, IgG, C reactive protein (CRP) and nitric oxide (NO) in saliva samples from 119 patients, who were divided into the control group (C), chronic renal failure (CRF) patient group and CRF patients on hemodialysis treatment (HD) group. IgA and IgG levels were analyzed by ELISA. Nitric oxide levels were determined indirectly by the nitrite concentration using Griess reagent; CRP by agglutination tests; and total proteins, by Bradford assay. The HD group showed significantly higher levels of IgG, IgA and CRP compared with the control and CRF groups. The CRF group presented the same amounts of IgG, IgA and CRP as the C group but significantly higher levels of NO similar to the HD group. Renal disease, particularly hemodialysis treatment during renal disease, seems to alter salivary immunological and inflammatory components. Thus, analyzing the levels of IgA, IgG, NO and CRP in saliva may be beneficial for monitoring renal disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radiologic imaging of the renal parenchyma structure and function.

Science.gov (United States)

Grenier, Nicolas; Merville, Pierre; Combe, Christian

2016-06-01

Radiologic imaging has the potential to identify several functional and/or structural biomarkers of acute and chronic kidney diseases that are useful diagnostics to guide patient management. A renal ultrasound examination can provide information regarding the gross anatomy and macrostructure of the renal parenchyma, and ultrasound imaging modalities based on Doppler or elastography techniques can provide haemodynamic and structural information, respectively. CT is also able to combine morphological and functional information, but the use of CT is limited due to the required exposure to X-ray irradiation and a risk of contrast-induced nephropathy following intravenous injection of a radio-contrast agent. MRI can be used to identify a wide range of anatomical and physiological parameters at the tissue and even cellular level, such as tissue perfusion, oxygenation, water diffusion, cellular phagocytic activity, tissue stiffness, and level of renal filtration. The ability of MRI to provide valuable information for most of these parameters within a renal context is still in development and requires more clinical experience, harmonization of technical procedures, and an evaluation of reliability and validity on a large scale.

[Prescribing diuretics: what a practitioner needs to know].

Science.gov (United States)

Richard, C; Saudan, P; Ernandez, T

2015-02-25

Diuretics are among the most frequently prescribed drugs. Most of them act by inhibiting sodium reabsorption in various nephron segments. By understanding their pharmacological characteristics, it is possible to adapt the type of diuretic to different clinical situations. Practical aspects of their use, including in heart failure, cirrhosis, the nephrotic syndrome and renal failure, are discussed.

Renal Replacement Therapy Modality in the ICU and Renal Recovery at Hospital Discharge.

Science.gov (United States)

Bonnassieux, Martin; Duclos, Antoine; Schneider, Antoine G; Schmidt, Aurélie; Bénard, Stève; Cancalon, Charlotte; Joannes-Boyau, Olivier; Ichai, Carole; Constantin, Jean-Michel; Lefrant, Jean-Yves; Kellum, John A; Rimmelé, Thomas

2018-02-01

Acute kidney injury requiring renal replacement therapy is a major concern in ICUs. Initial renal replacement therapy modality, continuous renal replacement therapy or intermittent hemodialysis, may impact renal recovery. The aim of this study was to assess the influence of initial renal replacement therapy modality on renal recovery at hospital discharge. Retrospective cohort study of all ICU stays from January 1, 2010, to December 31, 2013, with a "renal replacement therapy for acute kidney injury" code using the French hospital discharge database. Two hundred ninety-one ICUs in France. A total of 1,031,120 stays: 58,635 with renal replacement therapy for acute kidney injury and 25,750 included in the main analysis. None. PPatients alive at hospital discharge were grouped according to initial modality (continuous renal replacement therapy or intermittent hemodialysis) and included in the main analysis to identify predictors of renal recovery. Renal recovery was defined as greater than 3 days without renal replacement therapy before hospital discharge. The main analysis was a hierarchical logistic regression analysis including patient demographics, comorbidities, and severity variables, as well as center characteristics. Three sensitivity analyses were performed. Overall mortality was 56.1%, and overall renal recovery was 86.2%. Intermittent hemodialysis was associated with a lower likelihood of recovery at hospital discharge; odds ratio, 0.910 (95% CI, 0.834-0.992) p value equals to 0.0327. Results were consistent across all sensitivity analyses with odds/hazards ratios ranging from 0.883 to 0.958. In this large retrospective study, intermittent hemodialysis as an initial modality was associated with lower renal recovery at hospital discharge among patients with acute kidney injury, although the difference seems somewhat clinically limited.

Technical aspects of renal denervation in end-stage renal disease patients with challenging anatomy.

Science.gov (United States)

Spinelli, Alessio; Da Ros, Valerio; Morosetti, Daniele; Onofrio, Silvia D; Rovella, Valentina; Di Daniele, Nicola; Simonetti, Giovanni

2014-01-01

We describe our preliminary experience with percutaneous renal denervation in end-stage renal disease patients with resistant hypertension and challenging anatomy, in terms of the feasibility, safety, and efficacy of this procedure. Four patients with end-stage renal disease patients with resistant hypertension (mean hemodialysis time, 2.3 years) who had been taking at least four antihypertensive medications underwent percutaneous renal denervation. Renal artery eligibility included the absence of prior renal artery interventions, vessel stenosis renal denervation is a feasible approach for end-stage renal disease patients with resistant hypertension with encouraging short-term preliminary results in terms of procedural efficacy and safety.

Renal aquaporins and water balance disorders

DEFF Research Database (Denmark)

Kortenoeven, Marleen; Fenton, Robert A.

2013-01-01

BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, A......-solute diet and diuretics. GENERAL SIGNIFICANCE: In recent years, our understanding of the underlying mechanisms of water balance disorders has increased enormously, which has opened up several possible new treatment strategies.......BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, AQP......2, AQP3, AQP4 and AQP7. AQP2 in particular is regulated by vasopressin. SCOPE OF REVIEW: This review summarizes our current knowledge of the underlying mechanisms of various water balance disorders and their treatment strategies. MAJOR CONCLUSIONS: Dysfunctions of AQPs are involved in disorders...

Renal rescue of dopamine D2 receptor function reverses renal injury and high blood pressure

Science.gov (United States)

Konkalmatt, Prasad R.; Asico, Laureano D.; Zhang, Yanrong; Yang, Yu; Drachenberg, Cinthia; Zheng, Xiaoxu; Han, Fei; Jose, Pedro A.; Armando, Ines

2016-01-01

Dopamine D2 receptor (DRD2) deficiency increases renal inflammation and blood pressure in mice. We show here that long-term renal-selective silencing of Drd2 using siRNA increases renal expression of proinflammatory and profibrotic factors and blood pressure in mice. To determine the effects of renal-selective rescue of Drd2 expression in mice, the renal expression of DRD2 was first silenced using siRNA and 14 days later rescued by retrograde renal infusion of adeno-associated virus (AAV) vector with DRD2. Renal Drd2 siRNA treatment decreased the renal expression of DRD2 protein by 55%, and DRD2 AAV treatment increased the renal expression of DRD2 protein by 7.5- to 10-fold. Renal-selective DRD2 rescue reduced the expression of proinflammatory factors and kidney injury, preserved renal function, and normalized systolic and diastolic blood pressure. These results demonstrate that the deleterious effects of renal-selective Drd2 silencing on renal function and blood pressure were rescued by renal-selective overexpression of DRD2. Moreover, the deleterious effects of 45-minute bilateral ischemia/reperfusion on renal function and blood pressure in mice were ameliorated by a renal-selective increase in DRD2 expression by the retrograde ureteral infusion of DRD2 AAV immediately after the induction of ischemia/reperfusion injury. Thus, 14 days after ischemia/reperfusion injury, the renal expression of profibrotic factors, serum creatinine, and blood pressure were lower in mice infused with DRD2 AAV than in those infused with control AAV. These results indicate an important role of renal DRD2 in limiting renal injury and preserving normal renal function and blood pressure. PMID:27358912

Tc-99m-DMSA renal uptake rate and renal volume of elderly persons

International Nuclear Information System (INIS)

Ohishi, Yukihiko; Machida, Toyohei; Kido, Akira

1987-01-01

Renal function of erderly persons was evaluated by the radionuclide renal function test based on the renal uptake rate and the renal volume determined by Tc-99m-DMSA transectional tomographic images using single photon emission computed tomography (SPECT). Forty-three erderly cases (13 healthy persons and 30 patients with various types of renal disorders) aged between 60 and 87 on an average of 70 were studied and compared with results obtained from 20 healthy adults (18 - 45 years old). Renal volume was calculated from the summation of voxels in the region districted by equi-count threshold level (percentage to maximum count) on each section of the SPECT image. Attenuation correction was made by GE-STAR protocol utilizing Sorrenson's precorrection method. The renal uptake rate was expressed as a percentage of the total radioactivity detected within the renal volume, against an amount of dose injected. In the 26 kidneys of 13 healthy elderly persons, Tc-99m-DMSA renal uptake was 23 ± 5 %, which was significantly lower (p < 0.01) than that of healthy adults being 27 ± 2 %. A correlation coefficient between renal volume and uptake of 79 kidneys of 43 elderly persons was 0.5081 (p < 0.01). Creatinine clearance (Ccr) was better correlated with the total renal uptake (r = 0.6471, p < 0.01) than with the total renal volume (r = 0.3592, p < 0.01). This method is considered to be useful for clinical purpose as a test of renal function for elderly persons since it requires neither blood nor urine samples. (author)

Prospective MR image alignment between breath-holds: Application to renal BOLD MRI.

Science.gov (United States)

Kalis, Inge M; Pilutti, David; Krafft, Axel J; Hennig, Jürgen; Bock, Michael

2017-04-01

To present an image registration method for renal blood oxygen level-dependent (BOLD) measurements that enables semiautomatic assessment of parenchymal and medullary R2* changes under a functional challenge. In a series of breath-hold acquisitions, three-dimensional data were acquired initially for prospective image registration of subsequent BOLD measurements. An algorithm for kidney alignment for BOLD renal imaging (KALIBRI) was implemented to detect the positions of the left and right kidney so that the kidneys were acquired in the subsequent BOLD measurement at consistent anatomical locations. Residual in-plane distortions were corrected retrospectively so that semiautomatic dynamic R2* measurements of the renal cortex and medulla become feasible. KALIBRI was tested in six healthy volunteers during a series of BOLD experiments, which included a 600- to 1000-mL water challenge. Prospective image registration and BOLD imaging of each kidney was achieved within a total measurement time of about 17 s, enabling its execution within a single breath-hold. KALIBRI improved the registration by up to 35% as found with mutual information measures. In four volunteers, a medullary R2* decrease of up to 40% was observed after water ingestion. KALIBRI improves the quality of two-dimensional time-resolved renal BOLD MRI by aligning local renal anatomy, which allows for consistent R2* measurements over many breath-holds. Magn Reson Med 77:1573-1582, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

PET imaging and biodistribution analysis of the effects of succinylated gelatin combined with L-lysine on renal uptake and retention of ⁶⁴Cu-cyclam-RAFT-c(-RGDfK-)₄ in vivo.

Science.gov (United States)

Jin, Zhao-Hui; Furukawa, Takako; Sogawa, Chizuru; Claron, Michael; Aung, Winn; Tsuji, Atsushi B; Wakizaka, Hidekatsu; Zhang, Ming-Rong; Boturyn, Didier; Dumy, Pascal; Fujibayashi, Yasuhisa; Saga, Tsuneo

2014-04-01

(64)Cu-cyclam-RAFT-c(-RGDfK-)4, an αVβ3 integrin-targeting tetrameric cyclic RGD peptide probe, is a potential theranostic compound for positron emission tomography (PET) of tumor angiogenesis and for internal radiotherapy owing to the multiple decay modes of (64)Cu. Since kidneys are dose-limiting organs in internal radiotherapy, we aimed to reduce the renal accumulation of (64)Cu-cyclam-RAFT-c(-RGDfK-)4 by co-injection with Gelofusine (GF), a succinylated gelatin solution, and/or L-lysine (Lys), and to explore, for the first time, the related mechanisms using the noninvasive and quantitative PET imaging technology. Biodistribution assays, dynamic and static PET scans, and metabolism studies with radio-thin-layer chromatography (radio-TLC) were performed in healthy or αVβ3-positive tumor-bearing mice. In the results, co-injection with GF markedly reduced the renal uptake and slightly increased the tumor uptake of (64)Cu-cyclam-RAFT-c(-RGDfK-)4. L-Lysine alone had no effect on the probe biodistribution, but the combined use of Lys and GF tended to enhance the effect of GF. Dynamic PET and metabolite analysis by radio-TLC highly revealed that GF blocks the renal reabsorption of (64)Cu-cyclam-RAFT-c(-RGDfK-)4, but does not interfere with its metabolism and excretion. In conclusion, administration of GF and Lys is a useful strategy for kidney protection in (64)Cu-cyclam-RAFT-c(-RGDfK-)4-based internal radiotherapy. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Blood Pressure Response to Main Renal Artery and Combined Main Renal Artery Plus Branch Renal Denervation in Patients With Resistant Hypertension.

Science.gov (United States)

Fengler, Karl; Ewen, Sebastian; Höllriegel, Robert; Rommel, Karl-Philipp; Kulenthiran, Saaraaken; Lauder, Lucas; Cremers, Bodo; Schuler, Gerhard; Linke, Axel; Böhm, Michael; Mahfoud, Felix; Lurz, Philipp

2017-08-10

Single-electrode ablation of the main renal artery for renal sympathetic denervation showed mixed blood pressure (BP)-lowering effects. Further improvement of the technique seems crucial to optimize effectiveness of the procedure. Because sympathetic nerve fibers are closer to the lumen in the distal part of the renal artery, treatment of the distal main artery and its branches has been shown to reduce variability in treatment effects in preclinical studies and a recent randomized trial. Whether this optimized technique improves clinical outcomes remains uncertain. We report a 2-center experience of main renal artery and combined main renal artery plus branches renal denervation in patients with resistant hypertension using a multielectrode catheter. Twenty-five patients with therapy-resistant hypertension underwent renal sympathetic denervation with combined main renal artery and renal branch ablation and were compared to matched controls undergoing an ablation of the main renal artery only. BP change was assessed by ambulatory measurement at baseline and after 3 months. At baseline, BP was balanced between the groups. After 3 months, BP changed significantly in the combined ablation group (systolic/diastolic 24-hour mean and daytime mean BP -8.5±9.8/-7.0±10.7 and -9.4±9.8/-7.1±13.5 mm Hg, P renal artery and branches appears to improve BP-lowering efficacy and should be further investigated. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Renal angiographic and computed tomographic evaluation of local extension of renal cell carcinoma

International Nuclear Information System (INIS)

Masuda, Fujio; Onishi, Tetsuro; Sasaki, Tadamasa; Arai, Yoshikazu; Shoji, Ryo

1981-01-01

In 23 cases of renal cell carcinoma, the degree of local invasion of carcinoma was diagnosed using renal angiography and CT, and compared with the findings obtained by operation or autopsy. Among 5 cases in which the tumor was confined to the renal capsule, accurate diagnosis could be established with renal angiography in 4 cases and with CT in all of 5 cases. Both renal angiography and CT provided correct diagnosis in 7 of 8 cases in which the tumor showed infiltration extending to the perinephric fat. Out of 5 cases with tumor invasion of renal vein or inferior vena cava, diagnosis could be established correctly by renal angiography and CT in 3 cases. Among the remaining 2 cases the diagnosis could be established by renal angiography and CT in one each case. Among 5 cases with metastases to the regional lymph nodes, diagnosis could be established by renal angiography in only 2 cases, while all of 5 cases could be diagnosed by CT. In 3 cases where the tumor invaded an ajacent organ beyond Gerota's fastia, renal angiography could diagnose in none of the 3 cases while with CT all of 3 cases could successfully be diagnosed. The consistency of degree of local invasion as revealed by renal angiography and CT was seen in 15 of 23 cases (65%) for renal agniography and 20 of 23 cases (87%) for CT, indicating superiority of CT in this respect. In particular, CT appears to be more superior to renal angiography for determining whether the tumor confined to Gerota's fastia or it infiltrated over it. Both combined use of renal angiography and CT, the degree of infiltration of tumor could be diagnosed correctly in 22 of 23 cases (96%). (author)

Clinical application of calculated split renal volume using computed tomography-based renal volumetry after partial nephrectomy: Correlation with technetium-99m dimercaptosuccinic acid renal scan data.

Science.gov (United States)

Lee, Chan Ho; Park, Young Joo; Ku, Ja Yoon; Ha, Hong Koo

2017-06-01

To evaluate the clinical application of computed tomography-based measurement of renal cortical volume and split renal volume as a single tool to assess the anatomy and renal function in patients with renal tumors before and after partial nephrectomy, and to compare the findings with technetium-99m dimercaptosuccinic acid renal scan. The data of 51 patients with a unilateral renal tumor managed by partial nephrectomy were retrospectively analyzed. The renal cortical volume of tumor-bearing and contralateral kidneys was measured using ImageJ software. Split estimated glomerular filtration rate and split renal volume calculated using this renal cortical volume were compared with the split renal function measured with technetium-99m dimercaptosuccinic acid renal scan. A strong correlation between split renal function and split renal volume of the tumor-bearing kidney was observed before and after surgery (r = 0.89, P volumetry had a strong correlation with the split renal function measured using technetium-99m dimercaptosuccinic acid renal scan. Computed tomography-based split renal volume measurement before and after partial nephrectomy can be used as a single modality for anatomical and functional assessment of the tumor-bearing kidney. © 2017 The Japanese Urological Association.

Assessment of relative individual renal function based on DMSA uptake corrected for renal size

International Nuclear Information System (INIS)

Estorch, M.; Camacho, V.; Tembl, A.; Mena, I.; Hernandez, A.; Flotats, A.; Carrio, I.; Torres, G.; Prat, L.

2002-01-01

Decreased relative renal DMSA uptake can be a consequence of abnormal kidney size, associated with normal or impaired renal function. The quantification of relative renal function based on DMSA uptake in both kidneys is an established method for the assessment of individual renal function. Aim: To assess relative renal function by means of quantification of renal DMSA uptake corrected for kidney size. Results were compared with relative renal DMSA uptake without size correction, and were validated against the absolute renal DMSA uptake. Material and Methods: Four-hundred-forty-four consecutive patients (147 adults, mean age 14 years) underwent a DMSA study for several renal diseases. The relative renal function, based on the relative DMSA uptake uncorrected and corrected for renal size, and the absolute renal DMSA uptake were calculated. In order to relate the relative DMSA uptake uncorrected and corrected for renal size with the absolute DMSA uptake, subtraction of uncorrected (SU) and corrected (SC) relative uptake percentages of each pair of kidneys was obtained, and these values were correlated to the matched subtraction percentages of absolute uptake (SA). If the individual relative renal function is normal (45%-55%), the subtraction value is less or equal to 10%. Results: In 227 patients (51%) the relative renal DMSA uptake value was normal either uncorrected or corrected for renal size (A), and in 149 patients (34%) it was abnormal by both quantification methods (B). Seventy-seven patients (15%) had the relative renal DMSA uptake abnormal only by the uncorrected method (C). Subtraction value of absolute DMSA uptake percentages was not significantly different of subtraction value of relative DMSA uptake percentages corrected for renal size when relative uncorrected uptake was abnormal and corrected normal. where * p<0.0001, and p=NS. Conclusion: When uncorrected and corrected relative DMSA uptake are abnormal, the absolute uptake is also impaired, while when

Alteraciones renales en la drepanocitosis Renal disorders in sickle cell disease

Directory of Open Access Journals (Sweden)

Aramís Núñez-Quintana

2011-06-01

Full Text Available La drepanocitosis está asociada con un amplio espectro de alteraciones renales que tienen su base en la falciformación de los eritrocitos en los vasos de la médula renal, que conduce a fenómenos de isquemia, microinfartos y anomalías de la función tubular. Se producen también alteraciones glomerulares funcionales reversibles de la autorregulación renal (hiperfiltración, que pueden conducir a cambios anatómicos irreversibles con glomeruloesclerosis segmentaria focal. Estas anomalías se expresan tempranamente como microalbuminuria, proteinuria y de forma mas tardía, como síndrome nefrótico e insuficiencia renal crónica. Medidas terapéuticas como el uso de inhibidores de la enzima convertidora de la angiotensina II, de los bloqueadores del receptor de la angiotensina II, asociados o no con la hidroxiurea, pueden prevenir o retardar el daño glomerular. En el presente trabajo se exponen de forma resumida aspectos relacionados con la fisiopatología del daño renal en la drepanocitosis y su tratamiento.Sickle cell disease is associated with a wide range of renal disorders resulting from the falciformation of erythrocytes in vessels of the renal medulla, leading to ischemia, microinfarctions and tubular function abnormalities. Reversible glomerular functional renal self-regulation disorders (hyperfiltration also occur, which may lead to irreversible anatomical changes with focal segmental glomerular sclerosis. These anomalies are expressed at an early stage as microalbuminuria and proteinuria, and at a later stage as nephrotic syndrome and chronic renal failure. Therapeutic measures such as the use of angiotensin-II converting enzyme inhibitors and angiotensin-II receptor blockers, associated or not with hydroxyurea, may either prevent or delay glomerular damage. The paper succinctly presents the physiopathology of renal damage in drepanocytosis and its treatment.

Changes in the renin-angiotensin-aldosterone system in response to dietary salt intake in normal and hypertensive pregnancy. A randomized trial

DEFF Research Database (Denmark)

Nielsen, Lise Hald; Ovesen, Per; Hansen, Mie R

2016-01-01

It was hypothesized that primary renal sodium retention blunted the reactivity of the renin-angiotensin-aldosterone system to changes in salt intake in preeclampsia (PE). A randomized, cross-over, double-blinded, dietary intervention design was used to measure the effects of salt tablets or place...... of plasma renin and angiotensin II in response to changes in dietary salt intake compatible with a primary increase in renal sodium reabsorption in hypertensive pregnancies.......It was hypothesized that primary renal sodium retention blunted the reactivity of the renin-angiotensin-aldosterone system to changes in salt intake in preeclampsia (PE). A randomized, cross-over, double-blinded, dietary intervention design was used to measure the effects of salt tablets or placebo...

Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion

Science.gov (United States)

Mitch, William E.; Sands, Jeff M.

2015-01-01

Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance. PMID:25078422

A Renal Perforating Artery Mistaken for Arterial Bleeding after Percutaneous Renal Biopsy: A Case Report

International Nuclear Information System (INIS)

Kim, Ye Lim; Lee, Chang Hee; Kim, Kyeong Ah; Park, Cheol Min

2009-01-01

Perirenal hematoma after a renal biopsy is a common complication that usually resolves spontaneously, but this rarely requires transfusions or surgical/radiological intervention. We report here on a case of a renal perforating artery that was mistaken for renal arterial bleeding in a 53-year-old woman who was complicated with perirenal hematoma after undergoing a percutaneous renal biopsy. On the color and pulsed wave Doppler ultrasonography, linear blood flow was seen in the perirenal hematoma, which extended perpendicularly from the renal parenchyma into the perirenal space, and this linear blood flow exhibited an arterial pulse wave. On CT angiography, the renal perforating artery was demonstrated as a curvilinear vessel coursing tangentially to the renal margin and we decided that it was a pseudolesion caused by the renal perforating artery. A renal perforating artery may be mistaken for renal arterial bleeding after a percutaneous renal biopsy. A renal perforating artery and arterial bleeding can be differentiated by the location and shape seen on a color Doppler examination and the pulse waves characteristics

A Renal Perforating Artery Mistaken for Arterial Bleeding after Percutaneous Renal Biopsy: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Kim, Ye Lim; Lee, Chang Hee; Kim, Kyeong Ah; Park, Cheol Min [Korea University College of Medicine, Seoul (Korea, Republic of)

2009-12-15

Perirenal hematoma after a renal biopsy is a common complication that usually resolves spontaneously, but this rarely requires transfusions or surgical/radiological intervention. We report here on a case of a renal perforating artery that was mistaken for renal arterial bleeding in a 53-year-old woman who was complicated with perirenal hematoma after undergoing a percutaneous renal biopsy. On the color and pulsed wave Doppler ultrasonography, linear blood flow was seen in the perirenal hematoma, which extended perpendicularly from the renal parenchyma into the perirenal space, and this linear blood flow exhibited an arterial pulse wave. On CT angiography, the renal perforating artery was demonstrated as a curvilinear vessel coursing tangentially to the renal margin and we decided that it was a pseudolesion caused by the renal perforating artery. A renal perforating artery may be mistaken for renal arterial bleeding after a percutaneous renal biopsy. A renal perforating artery and arterial bleeding can be differentiated by the location and shape seen on a color Doppler examination and the pulse waves characteristics

Renal venogram

Science.gov (United States)

... be black. Other structures will be shades of gray. Veins are not normally seen in an x- ... Venogram - kidney; Renal vein thrombosis - venogram Images Kidney anatomy Kidney - blood and urine flow Renal veins References ...

[Anatomy character of renal artery and treatment of living-donor renal transplantation].

Science.gov (United States)

Zhang, Lei; Fei, Ji-guang; Chen, Li-zhong; Wang, Chang-xi; Deng, Su-xiong; Qiu, Jiang; Li, Jun; Chen, Guo-dong; Huang, Gang

2009-12-15

To study the anatomy characters of renal artery and the treatment of multiple arteries in living donor renal grafts. Records of 142 living donors were analyzed in our center. We analyzed the anatomic structure of renal arteries by DSA and CTA pre-transplantation. Thirty-one kidneys with multiple arteries were transplanted after reconstruction. Then clinical effects were compared between multiple-renal-arteries group (n=31) and single-renal-artery group (n=111). The incidence of multiple renal artery was 30.99%, and there was no difference between both sides (left kidney 22.54%, right kidney 22.13%). If the multiple artery occurred in left or right kidney, the incidence of the multiple artery occurred in the other side was 56.25% and 60.00%, respectively. The diameter of left main renal artery was more magnanimous (P=0.001) and the first branch was more closed to abdominal aorta (P=0.004). Operation time and warm/cool ischemia time were longer in the multiple-renal-arteries group. However, estimated blood loss, delayed graft function, acute rejection and flow rate of arcuate artery were similar in both groups, the same as serum creatinine and serum creatinine clearance rate on day 7, 1 month and 3 month post-operation. It was shown by repeated measures ANOVA that graft with multiple arteries didn't affect the tendency of renal function at early time post-operation. Comprehending the character of renal artery and accurate treatment of multiple artery anastomosis are critical for the effect of the living kidney transplantation.

Preemptive Renal Transplantation-The Best Treatment Option for Terminal Chronic Renal Failure.

Science.gov (United States)

Arze Aimaretti, L; Arze, S

2016-03-01

Renal transplantation is the best therapeutic option for end-stage chronic renal disease. Assuming that it is more advisable if performed early, we aimed to show the clinical, social, and economic advantages in 70% of our patients who were dialyzed only for a short period. For this purpose, we retrospectively collected data over 28 years in 142 kidney transplants performed in patients with renal transplantation with renal failure, especially in developing countries such as Bolivia, where until last year, full public support for renal replacement therapy was unavailable. Copyright © 2016 Elsevier Inc. All rights reserved.

Albumin uptake by renal lymphatics with and without obstruction of the renal vein

International Nuclear Information System (INIS)

Threefoot, S.A.; Pearson, J.E. Jr.; Georgiardis, A.

1989-01-01

Experiments involving injection of radio-iodinated albumin into the left renal arteries or left ureters of dogs indicate that the renal lymphatics are capable of a major contribution in returning to the circulation albumin (or other large molecules) escaping from renal capillaries. I-131-albumin was injected into the jugular vein of controls or into the left renal artery or in retrograde manner into the left ureter of female dogs. Experimental groups included those with no obstruction, occlusion of left renal veins or left renal lymphatics, or both. Collections were made from the right femoral artery, both renal veins, thoracic duct and both ureters at frequent intervals for 2 to 4 hours. Data analysis included I-131 concentration, specific activity, rate of recovery and selected ratios. After renal arterial injection, the percentage of I131 recovered in thoracic duct lymph of dogs without renal venous obstruction was 5 to 10 times that recovered in those that received injections into the jugular vein. In dogs with renal venous obstruction, recovery from the thoracic duct was 10 to 1,000 times that in control dogs. Most of the differences occurred during the first hour, after which time as recirculation and redistribution occurred the rates of appearance in thoracic duct lymph in each group were similar. The differences in the ratios of concentration in thoracic duct lymph to concentration in femoral arterial blood were also much greater when the renal vein was obstructed than in dogs with no obstruction. The greater return of albumin through the thoracic duct in those with impeded renal venous outflow was probably related to both sequestered concentration and increased intrarenal pressure

Incidental renal neoplasms

DEFF Research Database (Denmark)

Rabjerg, Maj; Mikkelsen, Minne Nedergaard; Walter, Steen

2014-01-01

On the basis of associations between tumor size, pathological stage, histological subtype and tumor grade in incidentally detected renal cell carcinoma vs symptomatic renal cell carcinoma, we discussed the need for a screening program of renal cell carcinoma in Denmark. We analyzed a consecutive...... series of 204 patients with renal tumors in 2011 and 2012. The tumors were classified according to detection mode: symptomatic and incidental and compared to pathological parameters. Eighty-nine patients (44%) were symptomatic, 113 (55%) were incidental. Information was not available in two patients...

Renal function study assessed by 99mTc-DMSA renal scintigraphy before and after PNL

International Nuclear Information System (INIS)

Sakurai, Masaki; Hioki, Takuichi; Okuno, Toshiyuki; Sugimura, Yoshiki; Yamakawa, Kensuke; Yanagawa, Makoto; Tajima, Kazuhiro; Tochigi, Hiromi; Kawamura, Juichi

1990-01-01

99m Tc-DMSA renal scintigraphy was carried out in 54 patients with unilateral renal stones before and after PNL. Four to 8 weeks after PNL the DMSA renal uptake significantly decreased to 17.2±6.0% from 18.2±6.7% before PNL. DMSA renal uptake did not change in the contralateral side. Since in some patients changes in the DMSA renal uptake of 5-7% were observed after PNL not only in the PNL side but also in the contralateral side, the renal function was assessed by the formula: DMSA renal uptake in the PNL side/DMSA renal uptake in the contralateral side, and the change of this ratio was evaluated in 44 patients, in whom the renal DMSA uptake in the PNL side was less than two times that in the contralateral side. The DMSA renal uptake ratio decreased to 95.6±8.7% from the base line 4-8 weeks after PNL. This change was statistically significant. Some functional risks such as massive bleeding with PNL, the fever after PNL and the number of nephrostomy tract did not affect the decrease in the renal function. In 29 patients in whom renal function was reevaluated one year after PNL, the DMSA renal uptake ratio significantly decreased to 94.2±9.6% from the base line 4-8 weeks after PNL. But the ratio significantly improved to 99.6±11.6% about one year after PNL. In two patients with a cold area on the renal image, the renal function of the operated side still remained at about 80% levels from the base line even one year after PNL. It is concluded that although renal function slightly decreased 4-8 weeks after PNL, it is expected to improve within one year after PNL. But in the case with a cold area on the renal image, the complete functional recovery would not be expected. 99m Tc-DMSA renal scintigraphy is a useful adjunct to evaluate the renal function before and after PNL. (author)

Allopurinol attenuates rhabdomyolysis-associated acute kidney injury: Renal and muscular protection.

Science.gov (United States)

Gois, Pedro H F; Canale, Daniele; Volpini, Rildo A; Ferreira, Daniela; Veras, Mariana M; Andrade-Oliveira, Vinicius; Câmara, Niels O S; Shimizu, Maria H M; Seguro, Antonio C

2016-12-01

Acute kidney injury (AKI) is the most severe complication of rhabdomyolysis. Allopurinol (Allo), a xanthine oxidase inhibitor, has been in the spotlight in the last decade due to new therapeutic applications related to its potent antioxidant effect. The aim of this study was to evaluate the efficacy of Allo in the prevention and treatment of rhabdomyolysis-associated AKI. Male Wistar rats were divided into five groups: saline control group; prophylactic Allo (300mg/L of drinking water, 7 days); glycerol (50%, 5ml/kg, IM); prophylactic Allo + glycerol; and therapeutic Allo (50mg/Kg, IV, 30min after glycerol injection) + glycerol. Glycerol-injected rats showed markedly reduced glomerular filtration rate associated with renal vasoconstriction, renal tubular damage, increased oxidative stress, apoptosis and inflammation. Allo ameliorated all these alterations. We found 8-isoprostane-PGF 2a (F2-IsoP) as a main factor involved in the oxidative stress-mediated renal vasoconstriction following rhabdomyolysis. Allo reduced F2-IsoP renal expression and restored renal blood flow. Allo also reduced oxidative stress in the damaged muscle, attenuated muscle lesion/inflammation and accelerated muscular recovery. Moreover, we showed new insights into the pathogenesis of rhabdomyolysis-associated AKI, whereas Allo treatment reduced renal inflammation by decreasing renal tissue uric acid levels and consequently inhibiting the inflammasome cascade. Allo treatment attenuates renal dysfunction in a model of rhabdomyolysis-associated AKI by reducing oxidative stress (systemic, renal and muscular), apoptosis and inflammation. This may represent a new therapeutic approach for rhabdomyolysis-associated AKI - a new use for an old and widely available medication. Copyright © 2016 Elsevier Inc. All rights reserved.

Renal artery and parenchymal changes after renal denervation: assessment by magnetic resonance angiography

Energy Technology Data Exchange (ETDEWEB)

Sanders, Margreet F.; Vink, Eva E.; Blankestijn, Peter J. [University Medical Center Utrecht, Department of Nephrology and Hypertension, PO Box 85500, Utrecht (Netherlands); Doormaal, Pieter Jan van; Habets, Jesse; Vonken, Evert-Jan; Leiner, Tim [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Beeftink, Martine M.A.; Verloop, Willemien L.; Voskuil, Michiel [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Bots, Michiel L. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Fadl Elmula, Fadl Elmula M. [Oslo University Hospital, Department of Internal Medicine and Department of Cardiology, Ullevaal, Oslo (Norway); Hammer, Frank [Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Hoffmann, Pavel [Oslo University Hospital, Section for Interventional Cardiology, Department of Cardiology, Ullevaal, Oslo (Norway); Jacobs, Lotte; Staessen, Jan A. [University of Leuven, Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, Leuven (Belgium); Mark, Patrick B.; Taylor, Alison H. [University of Glasgow, Institute of Cardiovascular and Medical Sciences, Glasgow, Scotland (United Kingdom); Persu, Alexandre; Renkin, Jean [Universite Catholique de Louvain, Pole of Cardiovascular Research, Institut de Recherche Experimentale et Clinique, Brussels (Belgium); Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Cardiology Department, Brussels (Belgium); Roditi, Giles [Glasgow Royal Infirmary, Department of Radiology, Glasgow (United Kingdom); Spiering, Wilko [University Medical Centre Utrecht, Department of Vascular Medicine, Utrecht (Netherlands); Collaboration: on behalf of the European Network COordinating research on Renal Denervation (ENCOReD) Consortium

2017-09-15

Relatively little is known about the incidence of long-term renal damage after renal denervation (RDN), a potential new treatment for hypertension. In this study the incidence of renal artery and parenchymal changes, assessed with contrast-enhanced magnetic resonance angiography (MRA) after RDN, is investigated. This study is an initiative of ENCOReD, a collaboration of hypertension expert centres. Patients in whom an MRA was performed before and after RDN were included. Scans were evaluated by two independent, blinded radiologists. Primary outcome was the change in renal artery morphology and parenchyma. MRAs from 96 patients were analysed. Before RDN, 41 renal anomalies were observed, of which 29 mostly mild renal artery stenoses. After a median time of 366 days post RDN, MRA showed a new stenosis (25-49% lumen reduction) in two patients and progression of pre-existing lumen reduction in a single patient. No other renal changes were observed and renal function remained stable. We observed new or progressed renal artery stenosis in three out of 96 patients, after a median time of 12 months post RDN (3.1%). Procedural angiographies showed that ablations were applied near the observed stenosis in only one of the three patients. (orig.)

Kidney in diabetes: from organ damage target to therapeutic target.

Science.gov (United States)

Salvatore, Teresa; Carbonara, Ornella; Cozzolino, Domenico; Torella, Roberto; Nasti, Rodolfo; Lascar, Nadia; Sasso, Ferdinando Carlo

2011-09-01

Despite the growing of pharmacological options for the treatment of diabetes, epidemiological studies suggest that a substantial proportion of patients does not achieve glycemic goals and so suffers from the risk of chronic complications. This review explores the inhibition of renal glucose reabsorption as a novel approach to treat hyperglycemia. Sodium-glucose cotransporter 2 (SGLT2), a low-affinity high-capacity transporter located in the brush-border membrane of the early segment (S1) of the proximal renal tubule, accounts for about 90% of the reabsorption of glucose from tubular fluid. Competitive inhibitors of SGLT2 that are responsible for renal excretion of glucose provide a unique mechanism to potentially lower the elevated blood glucose levels in patients with diabetes. They act independently of insulin secretion, thereby minimizing the risk of hypoglycemia and weight gain, to control energy balance in a negative direction, a distinctive advantage of this class of drugs over existing oral hypoglycemic agents. Although this group of medications is still under investigation, it appears to be safe and generally well tolerated and it would be expected to improve the treatment of type 2 diabetes as monotherapy or in combination with other oral or parenteral agents. Dapagliflozin is the first agent within this class, which induces clinically meaningful reductions in FPG, PPG, HbA1c, and body weight in type 2 diabetes.

Studies of the mechanism of contralateral polyuria after renal artery stenosis.

Science.gov (United States)

Galvez, O G; Roberts, B W; Mishkind, M H; Bay, W H; Ferris, T F

1977-01-01

Acute renal artery stenosis in hydropenic dogs caused a contralateral increase in urine volume and free water clearance without change in glomerular filtration, renal blood flow, or osmolar clearance. The increase in urine volume was not dependent on the development of hypertension since it occurred in animals pretreated with trimethaphan but was dependent upon angiotensin since it was presented with angiotensin blockade with Saralasin. The effect was not caused by angiotensin inhibiting antidiuretic hormone release since the polyuria occurred in hypophysectomized animals receiving a constant infusion of 10 muU/kg per min of aqueous Pitressin. Since the rise in urine volume was associated with an increase in renal vein prostaglandin E concentration and was prevented by pretreatment with indomethacin (5 mg/kg) the results suggest that the rise in plasma angiotensin after renal artery stenosis causes an increase in contralateral prostaglandin E synthesis with resultant antagonism to antidiuretic hormone at the collecting tubule. PMID:845253

Renal Sinus Fat Invasion and Tumoral Thrombosis of the Inferior Vena Cava-Renal Vein: Only Confined to Renal Cell Carcinoma

OpenAIRE

Turker Acar; Mustafa Harman; Serkan Guneyli; Sait Sen; Nevra Elmas

2014-01-01

Epithelioid angiomyolipoma (E-AML), accounting for 8% of renal angiomyolipoma, is usually associated with tuberous sclerosis (TS) and demonstrates aggressive behavior. E-AML is macroscopically seen as a large infiltrative necrotic tumor with occasional extension into renal vein and/or inferior vena cava. However, without history of TS, renal sinus and venous invasion E-AML would be a challenging diagnosis, which may lead radiologists to misinterpret it as a renal cell carcinoma (RCC). In this...

Acute renal failure in children

International Nuclear Information System (INIS)

Vergesslich, K.A.; Balzar, E.; Weninger, M.; Ponhold, W.; Sommer, G.; Wittich, G.R.; Vienna Univ.

1987-01-01

Acute renal failure (ARF) may be due to obstructive uropathy or renal parenchymal disease. Twenty-five children with acute renal failure secondary to renal parenchymal disease underwent ultrasonographic examination of the kidneys. Changes of renal size and cortical echogenicity were correlated with renal function. All patients presented with bilaterally enlarged kidneys with the exception in renal function resulted in normalization of renal size. With regard to cortical echogenicity two groups were formed. Group A comprised 11 patients whose kidneys had the same echogenicity as the liver, while in group B the kidneys were more echogenic (14 patients). Cortical echogenicity was always increased. Determination of creatinine levels showed a statistically significant difference between group A (3.32 mg% ± 1.40 S.D.) and group B (5.95 mg% ± 1.96 S.D.), p < 0.001. Changes in renal function were paralleled by rapid changes in renal size and cortical echogenicity. (orig.)

Renal tolerance for iopromide (ultravist) in patients with chronic renal failure. Preliminary report

International Nuclear Information System (INIS)

Golebiowski, M.; Pruszynski, B.

1993-01-01

The authors present the renal tolerance for nonionic low-osmotic contrast agent iopromide (ultravist) on the ground of literature and of angiographic examinations in 10 patients with chronic renal failure. One patient only had significant temporary deterioration of renal function. The presented results showed that analyzed agent is less nephrotoxic than high osmolality contrast agents. The use of iopromide is strongly recommended in patients with chronic renal failure. The risk of depression of renal function after administration of contrast material is minimized. (author)

Effect of Shenkang injection combined with hemodialysis treatment on renal function, renal anemia and cytokine levels in patients with chronic renal failure

Directory of Open Access Journals (Sweden)

Rui Liu

2016-10-01

Full Text Available Objective: To study the effect of Shenkang injection combined with hemodialysis treatment on renal function, renal anemia and cytokine levels in patients with chronic renal failure. Methods: A total of 68 patients with chronic renal failure who received hemodialysis treatment in our hospital during between October 2013 and February 2016 were selected and randomly divided into two groups, the observation group received Shenkang injection treatment in the process of dialysis, and the control group only received conventional symptomatic and supportive treatment. 8 weeks after treatment, serum was collected to determine the levels of renal function indexes, nutritional status indexes, anemia indexes and cytokines, and urine was collected to determine renal function indexes. Results: β2-MG, UA, Cr, phosphorus, IL-17, IL-23, CTGF, TGF-β1, FGF-2 and FGF-23 levels in serum as well as NGAL, KIM-1 and RBP levels in urine of observation group were significantly lower than those of control group, and TP, Alb, PA, calcium, Hb, EPO, Fe, TRF and FER levels in serum were significantly higher than those of control group. Conclusion: Shenkang injection combined with hemodialysis treatment helps to improve renal function, nutritional status and renal anemia, and reduce the synthesis of inflammation and renal interstitial fibrosis-related cytokines in patients with chronic renal failure.

Anatomic variations of the renal vessels: focus on the precaval right renal artery.

Science.gov (United States)

Bouali, Ourdia; Labarre, David; Molinier, François; Lopez, Raphaël; Benouaich, Vincent; Lauwers, Frédéric; Moscovici, Jacques

2012-07-01

The aim of this study was to determine the prevalence of precaval right renal artery and to investigate the distribution of renal arteries and veins. We discuss a theory of development of renal vascular variants. We retrospectively reviewed 120 arterial phase contrast material-enhanced spiral computerized tomography scans of the abdomen (1- to 2-mm section thickness) performed during a two-month period. Forty percent of the study group (48 patients) had one artery and one vein on each side, with typical course. There was a 9.17% prevalence of precaval right renal artery: 10 patients had a lower pole accessory artery in precaval position and one patient had the main and the accessory arteries that pass anterior to the inferior vena cava. In these cases, associated variations of renal vessels were higher than in the patients without precaval artery variant. There were multiple arteries in 28.3% of the right kidneys and in 26.7% of the left ones. Variants of the right renal vein consisted in multiple veins in 20% (24 cases). We detected no case of multiple left renal veins, but we described variations of its course (circum- or retroaortic vein) in 9.17% (11 cases). Twenty-six patients (21.7%) had associated variations of the renal pedicle. The current technical support allows for a minimally invasive study of vessels anatomy. In our study the prevalence of a precaval right renal artery appears to be higher than previously reported (9.17%). Knowledge on anatomical variations of right renal artery and associated renal vessels variations has major clinical implications.

Renal shear wave velocity by acoustic radiation force impulse did not reflect advanced renal impairment.

Science.gov (United States)

Takata, Tomoaki; Koda, Masahiko; Sugihara, Takaaki; Sugihara, Shinobu; Okamoto, Toshiaki; Miyoshi, Kenichi; Matono, Tomomitsu; Hosho, Keiko; Mae, Yukari; Iyama, Takuji; Fukui, Takeaki; Fukuda, Satoko; Munemura, Chishio; Isomoto, Hajime

2016-12-01

Acoustic radiation force impulse is a noninvasive method for evaluating tissue elasticity on ultrasound. Renal shear wave velocity measured by this technique has not been fully investigated in patients with renal disease. The aim of the present study was to compare renal shear wave velocity in end-stage renal disease patients and that in patients without chronic kidney disease and to investigate influencing factors. Renal shear wave velocities were measured in 59 healthy young subjects (control group), 31 subjects without chronic kidney disease (non-CKD group), and 39 end-stage renal disease patients (ESRD group). Each measurement was performed 10 times at both kidneys, and the mean value of eight of 10 measurements, excluding the maximum and minimum values, was compared. Renal shear wave velocity could be measured in all subjects. Renal shear wave velocity in the control group was higher than in the non-CKD group and in the ESRD group, and no difference was found between the non-CKD group and the ESRD group. Age and depth were negatively correlated to the renal shear wave velocity. In multiple regression analysis, age and depth were independent factors for renal shear wave velocity, while renal impairment was not. There was no difference between the non-CKD group and the ESRD group, even when ages were matched and depth was adjusted. Renal shear wave velocity was not associated with advanced renal impairment. However, it reflected alteration of renal aging, and this technique may be useful to detect renal impairment in the earlier stages. © 2015 Asian Pacific Society of Nephrology.

Curcumin-carrying nanoparticles prevent ischemia-reperfusion injury in human renal cells.

Science.gov (United States)

Xu, Yong; Hu, Ning; Jiang, Wei; Yuan, Hong-Fang; Zheng, Dong-Hui

2016-12-27

Renal ischemia-reperfusion injury (IRI) is a major complication in clinical practice. However, despite its frequency, effective preventive/treatment strategies for this condition are scarce. Curcumin possesses antioxidant properties and is a promising potential protective agent against renal IRI, but its poor water solubility restricts its application. In this study, we constructed curcumin-carrying distearoylphosphatidylethanolamine-polyethylene glycol nanoparticles (Cur-NPs), and their effect on HK-2 cells exposed to IRI was examined in vitro. Curcumin encapsulated in NPs demonstrated improved water solubility and slowed release. Compared with the IRI and Curcumin groups, Cur-NP groups displayed significantly improved cell viability, downregulated protein expression levels of caspase-3 and Bax, upregulated expression of Bcl-2 protein, increased antioxidant superoxide dismutase level, and reduced apoptotic rate, reactive oxygen species level, and malondialdehyde content. Results clearly showed that Cur-NPs demonstrated good water solubility and slow release, as well as exerted protective effects against oxidative stress in cultured HK-2 cells exposed to IRI.

Renal parenchyma thickness: a rapid estimation of renal function on computed tomography

International Nuclear Information System (INIS)

Kaplon, Daniel M.; Lasser, Michael S.; Sigman, Mark; Haleblian, George E.; Pareek, Gyan

2009-01-01

Purpose: To define the relationship between renal parenchyma thickness (RPT) on computed tomography and renal function on nuclear renography in chronically obstructed renal units (ORUs) and to define a minimal thickness ratio associated with adequate function. Materials and Methods: Twenty-eight consecutive patients undergoing both nuclear renography and CT during a six-month period between 2004 and 2006 were included. All patients that had a diagnosis of unilateral obstruction were included for analysis. RPT was measured in the following manner: The parenchyma thickness at three discrete levels of each kidney was measured using calipers on a CT workstation. The mean of these three measurements was defined as RPT. The renal parenchyma thickness ratio of the ORUs and non-obstructed renal unit (NORUs) was calculated and this was compared to the observed function on Mag-3 lasix Renogram. Results: A total of 28 patients were evaluated. Mean parenchyma thickness was 1.82 cm and 2.25 cm in the ORUs and NORUs, respectively. The mean relative renal function of ORUs was 39%. Linear regression analysis comparing renogram function to RPT ratio revealed a correlation coefficient of 0.48 (p * RPT ratio. A thickness ratio of 0.68 correlated with 20% renal function. Conclusion: RPT on computed tomography appears to be a powerful predictor of relative renal function in ORUs. Assessment of RPT is a useful and readily available clinical tool for surgical decision making (renal salvage therapy versus nephrectomy) in patients with ORUs. (author)

Renal ornithine decarboxylase activity, polyamines, and compensatory renal hypertrophy in the rat

International Nuclear Information System (INIS)

Humphreys, M.H.; Etheredge, S.B.; Lin, Shanyan; Ribstein, J.; Marton, L.J.

1988-01-01

The authors determined the role of ornithine decarboxylase (ODC) in compensatory renal hypertrophy (CRH) by relating renal ODC activity and polyamine content to kidney size, expressed as a percent of body weight, 1 wk after unilateral nephrectomy (UN). In normal rats, renal ODC activity increased after UN; 1 wk later the remaining kidney weight had increased. Renal concentration of putrescine, the product of ODC's decarboxylation of ornithine, was increased 3, 8, and 48 h after UN, but concentrations of polyamines synthesized later in the pathway, spermidine and spermine, were not appreciably affected. Pretreatment with difluoromethylornithine (DFMO), an irreversible inhibitor of ODC inhibited both base-line renal ODC activity and putrescine concentration as well as increases stimulated by UN, although concentrations of spermidine and spermine were not decreased. In hypophysectomized rats, both increased renal ODC activity and CRH occurred as well, indicating that these two consequences of UN do not require intact pituitary function. Thus stimulation of renal ODC activity and putrescine content do not appear critical to the process of CRH after UN

The rise and fall of novel renal magnesium transporters.

Science.gov (United States)

Schäffers, Olivier J M; Hoenderop, Joost G J; Bindels, René J M; de Baaij, Jeroen H F

2018-06-01

Body Mg 2+ balance is finely regulated in the distal convoluted tubule (DCT), where a tight interplay among transcellular reabsorption, mitochondrial exchange, and basolateral extrusion takes place. In the last decades, several research groups have aimed to identify the molecular players in these processes. A multitude of proteins have been proposed to function as Mg 2+ transporter in eukaryotes based on phylogenetic analysis, differential gene expression, and overexpression studies. However, functional evidence for many of these proteins is lacking. The aim of this review is, therefore, to critically reconsider all putative Mg 2+ transporters and put their presumed function in context of the renal handling of Mg 2+ . Sufficient experimental evidence exists to acknowledge transient receptor potential melastatin (TRPM) 6 and TRPM7, solute carrier family 41 (SLC41) A1 and SLC41A3, and mitochondrial RNA splicing 2 (MRS2) as Mg 2+ transporters. TRPM6/7 facilitate Mg 2+ influx, SLC41A1 mediates Mg 2+ extrusion, and MRS2 and SLC41A3 are implicated in mitochondrial Mg 2+ homeostasis. These proteins are highly expressed in the DCT. The function of cyclin M (CNNM) proteins is still under debate. For the other proposed Mg 2+ transporters including Mg 2+ transporter subtype 1 (MagT1), nonimprinted in Prader-Willi/Angelman syndrome (NIPA), membrane Mg 2+ transport (MMgT), Huntingtin-interacting protein 14 (HIP14), and ATP13A4, functional evidence is limited, or functions alternative to Mg 2+ transport have been suggested. Additional characterization of their Mg 2+ transport proficiency should be provided before further claims about their role as Mg 2+ transporter can be made.

The study on the factors for detection of renal stone on ultrasound

International Nuclear Information System (INIS)

Sim, Hyun Sun; Jung, Hong Ryang; Lim, Cheong Hwan

2006-01-01

Renal stones are common and typically arise within the collecting system. The renal sinus are contains the collection system, the renal vessels, lymphatcs, fat, and fibrous tissue. Because of the compression of all the large echoes in signal processing, the echo from the renal stone generally cannot be distinguished from large echoes emanating from normal structures of the renal sinus. Use of ultrasonography has been difficult for detecting small renal stone without posterior shadowing and chemical composition of stone. The aim of study was measuring for posterior acoustic shadowing to a stone for various scan parameter and it examines a help in renal stone diagnosis. The stone was place on sponge examined in a water bath with a 3.5 MHz or 7.5 HMz transducer (LOGIQ 400, USA). First, tested a variety of gain. Second, tested a variety of dynamic range. Third, tested a variety of focal zone. Fourth, measuring of the echo level for low and high frequency for depth. 1) Average echo level was 98 for low total gain (10 dB) and was 142 for high total gain (40 dB). Posterior acoustic shadowing of renal stone was clear for low gain. 2) Average echo level was 129 for low dynamic range (42 dB) and was 101 for high dynamic range (72 dB). Posterior acoustic shadowing of renal stone was clear for high dynamic range. 3) When stone is in focal zone of transducer, definite posterior acoustic shadow is identified. 4) Stone was clear appeared for high frequency (7.5 MHz) than low frequency (3.5 MHz) and it is not distorted. The demonstration of an posterior acoustic shadow of renal stone dependents on several technical factors such as gain, dynamic range, focus, and frequency. This various factors are a help in renal stone diagnosis

Renal pelvis urothelial carcinoma of the upper moiety in complete right renal duplex: a case report.

Science.gov (United States)

Zhang, Yiran; Yu, Quanfeng; Zhang, Zhihong; Liu, Ranlu; Xu, Yong

2015-01-01

Urothelial carcinoma (UC) originated from renal pelvis is the common tumor of the urinary system, however, neoplasia of the renal pelvis in duplex kidneys is extremely rare, especially in the complete renal and ureteral duplex cases. We present the first case of renal pelvis UC of the upper moiety in a complete right renal duplex. This male patient has bilateral complete renal and ureteral duplex. To the best of our knowledge, this is the first reported case of renal pelvis UC in a complete renal duplex system. After this experience we feel that the diagnosis of renal pelvis UC in duplex kidneys is not so easy, and once the diagnosis is determined, the whole renal duplex units and bladder cuff or ectopic orifice should be excised radically.

Photon Reabsorption in Mixed CsPbCl3:CsPbI3 Perovskite Nanocrystal Films for Light-Emitting Diodes

KAUST Repository

Davis, Nathaniel J. L. K.

2017-01-24

Cesium lead halide nanocrystals, CsPbX3 (X = Cl, Br, I), exhibit photoluminescence quantum efficiencies approaching 100% without the core–shell structures usually used in conventional semiconductor nanocrystals. These high photoluminescence efficiencies make these crystals ideal candidates for light-emitting diodes (LEDs). However, because of the large surface area to volume ratio, halogen exchange between perovskite nanocrystals of different compositions occurs rapidly, which is one of the limiting factors for white-light applications requiring a mixture of different crystal compositions to achieve a broad emission spectrum. Here, we use mixtures of chloride and iodide CsPbX3 (X = Cl, I) perovskite nanocrystals where anion exchange is significantly reduced. We investigate samples containing mixtures of perovskite nanocrystals with different compositions and study the resulting optical and electrical interactions. We report excitation transfer from CsPbCl3 to CsPbI3 in solution and within a poly(methyl methacrylate) matrix via photon reabsorption, which also occurs in electrically excited crystals in bulk heterojunction LEDs.

Mathematical modeling of renal hemodynamics in physiology and pathophysiology.

Science.gov (United States)

Sgouralis, Ioannis; Layton, Anita T

2015-06-01

In addition to the excretion of metabolic waste and toxin, the kidney plays an indispensable role in regulating the balance of water, electrolyte, acid-base, and blood pressure. For the kidney to maintain proper functions, hemodynamic control is crucial. In this review, we describe representative mathematical models that have been developed to better understand the kidney's autoregulatory processes. We consider mathematical models that simulate glomerular filtration, and renal blood flow regulation by means of the myogenic response and tubuloglomerular feedback. We discuss the extent to which these modeling efforts have expanded the understanding of renal functions in health and disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Alterações renais nas doenças falciformes Renal abnormalities in sickle cell disease

Directory of Open Access Journals (Sweden)

Isis Q. Magalhães

2007-09-01

abnormalities, hemodynamic changes and renal hormone synthesis alterations (erythropoietin, renin, prostaglandins. These changes appear in childhood with consequences including chronic anemia, increased blood flow and vaso-occlusion, especially within the renal medulla. In SS disease, the glomerular filtration rate (GFR is markedly higher in young patients but this drops with age. As a consequence of abnormalities in the distal nephron function there is reduced capacity of urine acidification, potassium excretion and hyposthenuria. Among the clinical effects of the latter are polyuria, nocturia, enuresis and a susceptability for dehydration. Abnormalities of the proximal tubular function include increased reabsorption of phosphates and b2 microglobulin and incresed secretion of uric acid and creatinine. For this reason, creatinine clearance significantly overestimates the glomerular filtration rate making creatinine learance inappropriate to detect early renal function impairment. Proteinuria occurs in 29-50% of over 10-years-old SS patients with 2/3 progressing to chronic renal failure. The use of angiotensin-converting enzyme inhibitor proves to be successful to reduce proteinuria which may have an impact of the progression of renal failure. Microalbuminuria is a sensitive marker of sickle nephropathy that precedes proteinuria. In pediatric population a prevalence of 19% of microbuminuria was observed; a percentage that increases with age and has a positive association with lower hemoglobin levels, higher leucocyte counts and acute chest syndrome. Screening for microalbuminuria is recommended from the age of 10 years old. A multicentric trial is ongoing with the aim of demonstrate potential benefits of early hydroxyurea therapy in the prevention of chronic organic lesions. (BabyHUG.

OBSTETRIC RENAL FAILURE

Directory of Open Access Journals (Sweden)

Rajeshwari

2015-11-01

Full Text Available Renal failure in obstetrics is rare but important complication, associated with significant mortality and long term morbidity.1,2 It includes acute renal failure due to obstetrical complications or due to deterioration of existing renal disease. AIMS AND OBJECTIVES: To evaluate the etiology and outcome of renal failure in obstetric patients. METHODS: We prospectively analyzed 30 pregnant and puerperal women with acute renal failure or pre-existing renal disease developing renal failure during pregnancy between November 2007 to sep-2009. Patients who presented/developed ARF during the hospital stay were included in this study. RESULTS: Among 30 patients, mean age was 23 years and 33 years age group. 12 cases (40% patients were primigravidae and 9(30% patients were multigravidae and 9 cases (30% presented in post-partum period. Eighteen cases (60% with ARF were seen in third trimester, followed by in postpartum period 9 cases (30%. Most common contributing factors to ARF were Pre-eclampsia, eclampsia and HELLP syndrome 60%, sepsis 56.6%, post abortal ARF 10%. DIC 40%. Haemorrhage as the aetiology for ARF was present 46%, APH in 20% and PPH in 26.6%. The type of ARF was renal in (63% and prerenal (36%; Oliguric seen in 10 patients (33% and high mortality (30%. Among the 20 pregnant patients with ARF, The average period of gestation was 33±2 weeks (30 -36 weeks, 5 cases (25% presented with intrauterine fetal demise and 18 cases (66% had preterm vaginal delivery and 2 cases (10% had induced abortion. And the average birth weight was 2±0.5 kg (1.5 kg. Eight cases (26% required dialysis. 80% of patients recovered completely of renal functions. 63% patients recovered without renal replacement therapy whereas 17% required dialysis. the maternal mortality was 20%, the main reason for mortality was septic shock and multi organ dysfunction (66%. CONCLUSION: ARF related pregnancy was seen commonly in the primigravidae and in the third trimester, the most

Renal nerves dynamically regulate renal blood flow in conscious, healthy rabbits.

Science.gov (United States)

Schiller, Alicia M; Pellegrino, Peter R; Zucker, Irving H

2016-01-15

Despite significant clinical interest in renal denervation as a therapy, the role of the renal nerves in the physiological regulation of renal blood flow (RBF) remains debated. We hypothesized that the renal nerves physiologically regulate beat-to-beat RBF variability (RBFV). This was tested in chronically instrumented, healthy rabbits that underwent either bilateral surgical renal denervation (DDNx) or a sham denervation procedure (INV). Artifact-free segments of RBF and arterial pressure (AP) from calmly resting, conscious rabbits were used to extract RBFV and AP variability for time-domain, frequency-domain, and nonlinear analysis. Whereas steady-state measures of RBF, AP, and heart rate did not statistically differ between groups, DDNx rabbits had greater RBFV than INV rabbits. AP-RBF transfer function analysis showed greater admittance gain in DDNx rabbits than in INV rabbits, particularly in the low-frequency (LF) range where systemic sympathetic vasomotion gives rise to AP oscillations. In the LF range, INV rabbits exhibited a negative AP-RBF phase shift and low coherence, consistent with the presence of an active control system. Neither of these features were present in the LF range of DDNx rabbits, which showed no phase shift and high coherence, consistent with a passive, Ohm's law pressure-flow relationship. Renal denervation did not significantly affect nonlinear RBFV measures of chaos, self-affinity, or complexity, nor did it significantly affect glomerular filtration rate or extracellular fluid volume. Cumulatively, these data suggest that the renal nerves mediate LF renal sympathetic vasomotion, which buffers RBF from LF AP oscillations in conscious, healthy rabbits. Copyright © 2016 the American Physiological Society.

Cardio-renal syndrome

OpenAIRE

Gnanaraj, Joseph; Radhakrishnan, Jai

2016-01-01

Cardio-renal syndrome is a commonly encountered problem in clinical practice. Its pathogenesis is not fully understood. The purpose of this article is to highlight the interaction between the cardiovascular system and the renal system and how their interaction results in the complex syndrome of cardio-renal dysfunction. Additionally, we outline the available therapeutic strategies to manage this complex syndrome.

Renal hemodynamic effects of activation of specific renal sympathetic nerve fiber groups.

Science.gov (United States)

DiBona, G F; Sawin, L L

1999-02-01

To examine the effect of activation of a unique population of renal sympathetic nerve fibers on renal blood flow (RBF) dynamics, anesthetized rats were instrumented with a renal sympathetic nerve activity (RSNA) recording electrode and an electromagnetic flow probe on the ipsilateral renal artery. Peripheral thermal receptor stimulation (external heat) was used to activate a unique population of renal sympathetic nerve fibers and to increase total RSNA. Total RSNA was reflexly increased to the same degree with somatic receptor stimulation (tail compression). Arterial pressure and heart rate were increased by both stimuli. Total RSNA was increased to the same degree by both stimuli but external heat produced a greater renal vasoconstrictor response than tail compression. Whereas both stimuli increased spectral density power of RSNA at both cardiac and respiratory frequencies, modulation of RBF variability by fluctuations of RSNA was small at these frequencies, with values for the normalized transfer gain being approximately 0.1 at >0.5 Hz. During tail compression coherent oscillations of RSNA and RBF were found at 0.3-0.4 Hz with normalized transfer gain of 0.33 +/- 0.02. During external heat coherent oscillations of RSNA and RBF were found at both 0.2 and 0.3-0.4 Hz with normalized transfer gains of 0. 63 +/- 0.05 at 0.2 Hz and 0.53 +/- 0.04 to 0.36 +/- 0.02 at 0.3-0.4 Hz. Renal denervation eliminated the oscillations in RBF at both 0.2 and 0.3-0.4 Hz. These findings indicate that despite similar increases in total RSNA, external heat results in a greater renal vasoconstrictor response than tail compression due to the activation of a unique population of renal sympathetic nerve fibers with different frequency-response characteristics of the renal vasculature.

Renal computed angiography. Part I: Renal CT arteriography in hypertension

International Nuclear Information System (INIS)

Al-Amin, M.; Hadjidekov, V.

2012-01-01

Visualization of renal vasculature is needed in several clinical condition among which hypertension is dominant. CT angiography now day replaces catheter angiography as non-invasive method. The goal of this study is to present initial authors experience in visualization of renal arteries using 64 MDCT and to evaluated the utility in hypertensive patients. MDCT assures excellent assessment of renal arteries conditions. Multiplanar reconstruction and allow better delineation in tortuous vessels course and anatomic variants. (authors)

Renal sympathetic nervous system and the effects of denervation on renal arteries.

Science.gov (United States)

Kannan, Arun; Medina, Raul Ivan; Nagajothi, Nagapradeep; Balamuthusamy, Saravanan

2014-08-26

Resistant hypertension is associated with chronic activation of the sympathetic nervous system resulting in various comorbidities. The prevalence of resistant hypertension is often under estimated due to various reasons. Activation of sympathetic nervous system at the renal- as well as systemic- level contributes to the increased level of catecholamines and resulting increase in the blood pressure. This increased activity was demonstrated by increased muscle sympathetic nerve activity and renal and total body noradrenaline spillover. Apart from the hypertension, it is hypothesized to be associated with insulin resistance, congestive heart failure and obstructive sleep apnea. Renal denervation is a novel procedure where the sympathetic afferent and efferent activity is reduced by various techniques and has been used successfully to treat drug-resistant hypertension improvement of various metabolic derangements. Renal denervation has the unique advantage of offering the denervation at the renal level, thus mitigating the systemic side effects. Renal denervation can be done by various techniques including radiofrequency ablation, ultrasound guided ablation and chemical ablation. Various trials evaluated the role of renal denervation in the management of resistant hypertension and have found promising results. More studies are underway to evaluate the role of renal denervation in patients presenting with resistant hypertension in different scenarios. Appropriate patient selection might be the key in determining the effectiveness of the procedure.

Role of renal vascular potassium channels in physiology and pathophysiology

DEFF Research Database (Denmark)

Salomonsson, Max; Brasen, Jens Christian; Sorensen, Charlotte Mehlin

2017-01-01

The control of renal vascular tone is important for the regulation of salt and water balance, blood pressure and the protection against damaging elevated glomerular pressure. The K+ conductance is a major factor in the regulation of the membrane potential (Vm ) in vascular smooth muscle (VSMC...... the ambiguous in vitro and in vivo results. We discuss the role of single types of K+ channels and the integrated function of several classes. We also deal with the possible role of renal vascular K+ channels in the pathophysiology of hypertension, diabetes mellitus and sepsis. This article is protected...

Resolving an 80-yr-old controversy: the beginning of the modern era of renal physiology.

Science.gov (United States)

Jamison, Rex L

2014-12-01

Marcello Malpighi discovered the glomerulus that bears his name in the 17th century, but it was not until the middle of the 19th century, in 1842, that William Bowman in London published his studies of the histological structure of the glomerulus and proposed that urine formation begins with glomerular secretion. At nearly the same time in Marburg, Carl Ludwig, unaware of Bowman's findings, proposed that urine formation begins with glomerular filtration followed by tubule reabsorption. The controversy lasted 80 yr. Prominent investigators weighed in on both sides. Rudolph Heidenhain's findings in 1874 swung the pendulum toward Bowman's theory until Arthur Cushny published his book, The Secretion of Urine, in 1917, in which he found the evidence insufficient to prove either theory. In 1921, a young physician, Joseph Wearn, began his postresidency training in the laboratory of Alfred N. Richards. He read Cushny's book and learned how to expose the glomerulus of a living frog. Richards proposed that Wearn use that experimental preparation to inject epinephrine into the glomerulus. Wearn proposed a different experiment: instead of using injection, collect fluid from the glomerulus and analyze it. Richards agreed, and the landmark results of that experiment, published in 1924, settled the controversy. The modern era of renal physiology was born. Copyright © 2014 The American Physiological Society.

Zeeman effect on disalignment of excited atoms by radiation re-absorption: neon 2p2 atoms in a discharge plasma

International Nuclear Information System (INIS)

Deguchi, K; Imagawa, T; Shikama, T; Hasuo, M

2009-01-01

We have measured the relaxation rate of alignment of neon atoms in a 2p 2 (in Paschen notation) level, which were excited by a linearly polarized laser pulse in a glow discharge plasma at 77 K, in a magnetic field of up to 3 T in the Voigt configuration. The relaxation rate decreased with an increase in the magnetic field strength of up to 0.5 T and showed no magnetic field dependence above 0.5 T. We developed a Monte Carlo simulation method to calculate alignment relaxation, or disalignment, by radiation re-absorption of atomic resonance lines in a magnetic field. The simulated result was found to be consistent with the observed magnetic field dependence. We analysed the results of the simulation from a point of competition between the Zeeman splitting and the Doppler broadening of the transition lines from the 2p 2 level.

ERK Regulates Renal Cell Proliferation and Renal Cyst Expansion in inv Mutant Mice

International Nuclear Information System (INIS)

Okumura, Yasuko; Sugiyama, Noriyuki; Tanimura, Susumu; Nishida, Masashi; Hamaoka, Kenji; Kohno, Michiaki; Yokoyama, Takahiko

2009-01-01

Nephronophthisis (NPHP) is the most frequent genetic cause of end-stage kidney disease in children and young adults. Inv mice are a model for human nephronophthisis type 2 (NPHP2) and characterized by multiple renal cysts and situs inversus. Renal epithelial cells in inv cystic kidneys show increased cell proliferation. We studied the ERK pathway to understand the mechanisms that induce cell proliferation and renal cyst progression in inv kidneys. We studied the effects of ERK suppression by administering PD184352, an oral mitogen-activated protein kinase kinase (MEK) inhibitor on renal cyst expansion, extracellular signal-regulated protein kinase (ERK) activity, bromo-deoxyuridine (BrdU) incorporation and expression of cell-cycle regulators in invΔC kidneys. Phosphorylated ERK (p-ERK) level increased along with renal cyst enlargement. Cell-cycle regulators showed a high level of expression in invΔC kidneys. PD184352 successfully decreased p-ERK level and inhibited renal cyst enlargement. The inhibitor also decreased expression of cell-cycle regulators and BrdU incorporation in renal epithelial cells. The present results showed that ERK regulated renal cell proliferation and cyst expansion in inv mutants

Renal artery stenosis

International Nuclear Information System (INIS)

Desberg, A.; Paushter, D.M.; Lammert, G.K.; Hale, J.; Troy, R.; Novic, A.; Nally, J. Jr.

1989-01-01

Renal artery disease is a potentially correctable cause of hypertension. Previous studies have suggested the utility of duplex sonography in accurately detecting and grading the severity of renal artery stenosis. The purpose of this paper is to evaluate color flow Doppler for this use. Forty-three kidneys were examined by color-flow Doppler and conventional duplex sampling in patients with suspected renovascular hypertension or those undergoing aortography for unrelated reasons. Doppler tracings were obtained from the renal arteries and aorta with calculation of the renal aortic ratio (RAR) and resistive index (RI). Results of Doppler sampling with color flow guidance were compared with aortograms in a blinded fashion

Analysis of accumulation of 99mTc-octreotide and 99mTc-EDDA/HYNIC-Tyr3-octreotide in the rat kidneys.

Science.gov (United States)

Kopecky, Martin; Semecky, Vladimir; Trejtnar, Frantisek; Laznicek, Milan; Laznickova, Alice; Nachtigal, Petr; Decristoforo, Clemens; Mather, Stephen J; Mäcke, Helmut R

2004-02-01

The aim of this study was to compare renal handling and distribution of (99m)Tc-octreotide and (99m)Tc-EDDA/HYNIC-Tyr(3)-octreotide (HYNIC-TOC) in rats. In kidney perfusion experiments, the renal clearance value of (99m)Tc-octreotide was three times lower than that of (99m)Tc-EDDA/HYNIC-TOC. The predominant renal excretion of (99m)Tc-EDDA/HYNIC-TOC was associated with a high and long-term renal accumulation up to 48 hrs. Microautoradiographic results indicated that (99m)Tc-EDDA/HYNIC-TOC was retained mainly in the renal medulla within the cells of the collecting ducts and in the surrounding tissue. Lower positivity was found in the proximal and distal tubular cells. We conclude that the mechanism of renal accumulation of somatostatin analogues renal accumulation is complex and that proximal tubular reabsorption is probably not the main mechanism for uptake of (99m)Tc-EDDA/HYNIC-TOC in the kidneys. The presence of the somatostatin receptors, differences in the tonicity level within kidneys and other possible mechanisms could participate in their renal accumulation.

Analysis of accumulation of 99mTc-octreotide and 99mTc-EDDA/HYNIC-Tyr3-octreotide in the rat kidneys

International Nuclear Information System (INIS)

Kopecky, Martin; Semecky, Vladimir; Trejtnar, Frantisek; Laznicek, Milan; Laznickova, Alice; Nachtigal, Petr; Decristoforo, Clemens; Mather, Stephen J.; Maecke, Helmut R.

2004-01-01

The aim of this study was to compare renal handling and distribution of 99m Tc-octreotide and 99m Tc-EDDA/HYNIC-Tyr 3 -octreotide (HYNIC-TOC) in rats. In kidney perfusion experiments, the renal clearance value of 99m Tc-octreotide was three times lower than that of 99m Tc-EDDA/HYNIC-TOC. The predominant renal excretion of 99m Tc-EDDA/HYNIC-TOC was associated with a high and long-term renal accumulation up to 48 hrs. Microautoradiographic results indicated that 99m Tc-EDDA/HYNIC-TOC was retained mainly in the renal medulla within the cells of the collecting ducts and in the surrounding tissue. Lower positivity was found in the proximal and distal tubular cells. We conclude that the mechanism of renal accumulation of somatostatin analogues renal accumulation is complex and that proximal tubular reabsorption is probably not the main mechanism for uptake of 99m Tc-EDDA/HYNIC-TOC in the kidneys. The presence of the somatostatin receptors, differences in the tonicity level within kidneys and other possible mechanisms could participate in their renal accumulation

Cystinuria in the maned wolf of South America.

Science.gov (United States)

Bovée, K C; Bush, M; Dietz, J; Jezyk, P; Segal, S

1981-05-22

Of 42 maned wolves in zoos or live-trapped in Brazil, 34 had excessive cystine in their urine. Renal clearance studies of five of the affected wolves revealed a variable defect for the reabsorption of cystine and dibasic amino acids. The renal tubular handling of other solutes including glucose, phosphate, sodium, potassium, and uric acid was considered normal. Urinary calculi composed of cystine were found in four wolves and proved fatal in three of them. With the exception of the high incidence in this species, this hereditary disease resembles the disorder described in dogs and humans.

Hypophosphatemic osteomalacia in von Recklinghausen neurofibromatosis: Case report and literature review

Directory of Open Access Journals (Sweden)

Aman Gupta

2015-01-01

Full Text Available Osteomalacia in neurofibromatosis is a rare entity and distinct from more common dysplastic skeletal affections of this disease. As a rule, it is characterized by later onset in adulthood. There is renal phosphate loss with hypophosphatemia and multiple pseudofractures in the typical cases. The hypophosphatemic conditions that interfere in bone mineralization comprise many hereditary or acquired diseases, all of them sharing the same pathophysiological mechanism-reduction in phosphate reabsorption by the renal tubuli. This process leads to chronic hyperphosphaturia and hypophosphatemia, associated with inappropriately normal or low levels of calcitriol, causing rickets in children and osteomalacia in adults.

Predictors of renal recovery in patients with pre-orthotopic liver transplant (OLT) renal dysfunction.

Science.gov (United States)

Iglesias, Jose; Frank, Elliot; Mehandru, Sushil; Davis, John M; Levine, Jerrold S

2013-07-13

Renal dysfunction occurs commonly in patients awaiting orthotopic liver transplantation (OLT) for end-stage liver disease. The use of simultaneous liver-kidney transplantation has increased in the MELD scoring era. As patients may recover renal function after OLT, identifying factors predictive of renal recovery is a critical issue, especially given the scarcity of available organs. Employing the UNOS database, we sought to identify donor- and patient-related predictors of renal recovery among 1720 patients with pre-OLT renal dysfunction and transplanted from 1989 to 2005. Recovery of renal function post-OLT was defined as a composite endpoint of serum creatinine (SCr) ≤1.5 mg/dL at discharge and survival ≥29 days. Pre-OLT renal dysfunction was defined as any of the following: SCr ≥2 mg/dL at any time while awaiting OLT or need for renal replacement therapy (RRT) at the time of registration and/or OLT. Independent predictors of recovery of renal function post-OLT were absence of hepatic allograft dysfunction, transplantation during MELD era, recipient female sex, decreased donor age, decreased recipient ALT at time of OLT, decreased recipient body mass index at registration, use of anti-thymocyte globulin as induction therapy, and longer wait time from registration. Contrary to popular belief, a requirement for RRT, even for prolonged periods in excess of 8 weeks, was not an independent predictor of failure to recover renal function post-OLT. These data indicate that the duration of renal dysfunction, even among those requiring RRT, is a poor way to discriminate reversible from irreversible renal dysfunction.

[Immunoglobulin filtration and reabsorption as possible factors in the pathogenesis of chronic glomerulonephritis. Clinical, immunomorphological and histoenzymological research].

Science.gov (United States)

Nabokov, A V; Travkina, E S; Zel'tser, G L; Nevorotin, A I

1992-01-01

Kidney biopsy specimens obtained from a group of individuals with chronic glomerulonephritis (CGN) have been processed for light and electron microscopic immunolocalization of total immunoglobulins (Igs). In a few cases, acid phosphatase (ACPase), a lysosomal enzyme marker, was ultrastructurally visualized. In the glomeruli, horseradish peroxidase-stained Igs were revealed in capillary lumina, urinary spaces and in transit through occasional loci of the glomerular basal membranes while ACPase-containing lysosomes resided both within and outside the cells. In the proximal tubules, Igs were traced in the endocytic vesicles and vacuoles, the latter also being positive for ACPase. Statistically significant relationships have been revealed between the number of IGs-labeled proximal tubules and some clinical or pathomorphological stigmata of CGN, in particular, proteinuria and arterial hypertension levels, marked interstitial sclerosis, etc. The data obtained are discussed in regard to the mechanisms of increased macromolecular filtration and the different proteinuria selectivity levels as well as the development of interstitial sclerosis as a result of the elevated reabsorption and incomplete lysosomal degradation of Igs in CGN.

Dynamic renal scintigraphy in aortic disorders

International Nuclear Information System (INIS)

Terae, Satoshi; Itoh, Kazuo; Tsukamoto, Eriko; Nakada, Kunihiro; Fujimori, Kenji; Hashimoto, Masato; Tanabe, Tatsuzo; Furudate, Masayori; Irie, Goro

1986-01-01

Dynamic renal scintigraphy has been reviewed for evaluation of renal arterial involvement in aortic disorders such as arteriosclerosis obliterans, abdominal aortic aneurysm and dissecting aneurysm. As a diagnostic finding and parameters, we used blood perfusion images of both kidneys and relative split renal function index obtained with analysis of the time-activity curves which were generated using a renal region of interest. In the diagnosis of unilateral renal arterial involvement, sensitivity and specificity of blood perfusion images were 100 % (9/9) and 77 % (10/13) and those of relative split renal function index were 78 % (7/9) and 92 % (12/13), respectively. Dynamic renal scintigraphy was useful for evaluating unilateral renal arterial involvement in aortic diseases. However, scintigraphic diagnosis of bilateral renal arterial involvement were difficult. And in a severe case, we could not differentiate renal parenchymal damage due to renovascular involvement from senile renal dysfunction or hypertensive renal disease which is often a cause of aortic disorders. (author)

Taurine decreased uric acid levels in hyperuricemic rats and alleviated kidney injury.

Science.gov (United States)

Feng, Ying; Sun, Fang; Gao, Yongchao; Yang, Jiancheng; Wu, Gaofeng; Lin, Shumei; Hu, Jianmin

2017-07-29

Hyperuricemia can lead to direct kidney damage. Taurine participates in several renal physiological processes and has been shown as a renoprotective agent. It has been reported that taurine could reduce uric acid levels in diabetic rats, but to date there was no research on the effects of taurine on hyperuricemic rats with kidney injury. In present study, hyperuricemic rat models were induced by intragastric administration of adenine and ethambutol hydrochloride for 10 days, and taurine (1% or 2%) were added in the drinking water 7 days in advance for consecutively 17 days. The results showed that taurine alleviated renal morphological and pathological changes as well as kidney dysfunction in hyperuricemic rats. Taurine could efficiently decrease the elevated xanthine oxidase activities in hyperuricemic rats, indicating its effect on the regulation of uric acid formation. The reabsorption and secretion of uric acid are dependent on a number of urate transporters. Expressions of three urate transporters were significantly down-regulated in hyperuricemic rats, while taurine prevented the decrease of mRNA and protein expression levels of these urate transporters. The results indicate that taurine might play a role in the regulation of renal uric acid excretion. Therefore, taurine could be a promising agent for the treatment of hyperuricemia. Copyright © 2017 Elsevier Inc. All rights reserved.

Perioperative acute renal failure.

LENUS (Irish Health Repository)

Mahon, Padraig

2012-02-03

PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

Spiral CT in kidney: assumption of renal function by objective evaluation of renal cortical enhancement

International Nuclear Information System (INIS)

Choi, Bo Yoon; Lee, Jong Seok; Lee, Joon Woo; Myung, Jae Sung; Sim, Jung Suk; Seong, Chang Kyu; Kim, Seung Hyup; Choi, Guk Myeong; Chi, Seong Whi

2000-01-01

To correlate the degree of renal cortical enhancement, objectively evaluated by means of spiral CT with the serum level of creatinine, and to determine the extent to which this degree of enhancement may be used to detect renal parenchymal disease. Eighty patients (M:F = 50:30; age + 25-19, (mean 53) years) with available serum level of creatinine who underwent spiral CT between September and October 1999 were included in this study. In fifty patients the findings suggested hepatic or biliary diseases such as hepatoma, biliary cancer, or stone, while in thirty, renal diseases such as cyst, hematoma, or stone appeared to be present. Spiral CT imaging of the cortical phase was obtained at 30-40 seconds after the injection of 120 ml of non-ionic media at a rate of 3 ml/sec. The degree of renal cortical enhancement was calculated by dividing the CT attenuation number of renal cortex at the level of the renal hilum by the CT attenuation number of aorta at the same level. The degree of renal cortical enhancement was compared with the serum level of creatinine, and the degree of renal cortical enhancement in renal parenchymal disease with that of the normal group. Among eighty patients there were five with renal parenchymal disease and 75 with normal renal function. The ratio of the CT attenuation number of renal cortex to that of aorta at the level of the renal hilum ranged between 0.49 and 0.99 (mean, 0.79; standard deviation, 0.15). while the serum level of creatinine ranged between 0.6 and 3.2 mg/dl. There was significant correlation (coefficient of -0.346) and a statistically significant probability of 0.002 between the ratio of the CT attenuation numbers and the serum level of creatinine. There was a significant difference (statistically significant probability of less than 0.01) between those with renal parenchymal disease and the normal group. The use of spiral CT to measure the degree of renal cortical enhancement provides not only an effective index for

The effects of sodium-glucose co-transporter 2 inhibitors in patients with type 2 diabetes

DEFF Research Database (Denmark)

Storgaard, Heidi; Gluud, Lise Lotte; Christensen, Mikkel

2014-01-01

INTRODUCTION: Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) increase urinary glucose excretion through a reduced renal glucose reabsorption. We plan to perform a systematic review of SGLT-2i for treatment of type 2 diabetes. METHODS AND ANALYSIS: A systematic review with meta-analyses of r......INTRODUCTION: Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) increase urinary glucose excretion through a reduced renal glucose reabsorption. We plan to perform a systematic review of SGLT-2i for treatment of type 2 diabetes. METHODS AND ANALYSIS: A systematic review with meta......-analyses of randomised clinical trials on SGLT-2i versus placebo, other oral glucose lowering drugs or insulin for patients with type 2 diabetes will be performed. The primary end point will be the glycated haemoglobin. Secondary end points will include changes in body weight, body mass index, fasting plasma glucose......, plasma cholesterol, kidney and liver blood tests, blood pressure and adverse events. Electronic (the Cochrane Library, MEDLINE, EMBASE and the Science Citation Index) and manual searches will be performed. Meta-analyses will be performed and the results presented as mean differences for continuous...

Comparison of para-aminophenol cytotoxicity in rat renal epithelial cells and hepatocytes.

Science.gov (United States)

Li, Ying; Bentzley, Catherine M; Tarloff, Joan B

2005-04-01

Several chemicals, including para-aminophenol (PAP), produce kidney damage in the absence of hepatic damage. Selective nephrotoxicity may be related to the ability of the kidney to reabsorb filtered water, thereby raising the intraluminal concentration of toxicants and exposing tubular epithelial cells to higher concentrations than would be present in other tissues. The present experiments tested the hypothesis that hepatocytes and renal epithelial cells exposed to equivalent concentrations of PAP would be equally susceptible to toxicity. Hepatocytes and renal epithelial cells were prepared by collagenase digestion of tissues obtained from female Sprague-Dawley rats. Toxicity was monitored using trypan blue exclusion, oxygen consumption and ATP content. We measured the rate of PAP clearance and formation of PAP-glutathione conjugate by HPLC. We found that renal epithelial cells accumulated trypan blue and showed declines in oxygen consumption and ATP content at significantly lower concentrations of PAP and at earlier time points than hepatocytes. The half-life of PAP in hepatocyte incubations was significantly shorter (0.71+/-0.07 h) than in renal epithelial cell incubations (1.33+/-0.23 h), suggesting that renal epithelial cells were exposed to PAP for longer time periods than hepatocytes. Renal epithelial cells formed significantly less glutathione conjugates of PAP (PAP-SG) than did hepatocytes, consistent with less efficient detoxification of reactive PAP intermediates by renal epithelial cells. Finally, hepatocytes contained significant more reduced glutathione (NPSH) than did renal epithelial cells, possibly explaining the enhanced formation of PAP-SG by this cell population. In conclusion, our data indicates that renal epithelial cells are intrinsically more susceptible to PAP cytotoxicity than are hepatocytes. This enhanced cytotoxicity may be due to longer exposure to PAP and/or reduced detoxification of reactive intermediates due to lower concentrations

Studies on the evaluation of renal function in urological renal disorders with 99mTc-DMSA renal uptake, 1

International Nuclear Information System (INIS)

Takeda, Masayuki

1987-01-01

The change of normal value of 99m Tc-dimercaptosuccinic acid (DMSA) renal uptake with age was investigated, and the correlation between total renal uptake of 99m Tc-DMSA and 24-hour endogenous creatinine clearance was studied in each age group separately. (1) 99m Tc-DMSA renal uptake was measured in 107 normal controls without renal or urinary tract diseases between 0 and 67 years old and normal values were analyzed in each age group. The normal value was highest in the age group of 0 ∼ 9 years old and was gradually decreased with age. Over 20 years old, the normal value hardly changed. (2) The lower limit of normal values of 99m Tc-DMSA renal uptake in each kidney was 19.62, 13.89, 13.18, 11.58, 12.00, 10.24 % in the age groups of 0 ∼ 9, 10 ∼ 19, 20 ∼ 29, 30 ∼ 39, 40 ∼ 49, 50 ∼ 59 years old, respectively. (3) Correlations between total renal uptake and 24-hour endogenous creatinine clearance were investigated in each age group in 248 patients between 0 and 79 years old. Positive linear correlations were found in the age groups of 0 ∼ 9, 10 ∼ 19, 20 ∼ 29, 30 ∼ 39, 40 ∼ 49, 50 ∼ 59, 60 ∼ 69, 70 ∼ 79 years old, and especially above 50 years old closer correlations were found. It is concluded that although 99m Tc-DMSA renal uptake is a useful method for renal function test through life, the change with age must be considered in the evaluation of its value. (author)

Eppur Si Muove: The dynamic nature of physiological control of renal blood flow by the renal sympathetic nerves.

Science.gov (United States)

Schiller, Alicia M; Pellegrino, Peter Ricci; Zucker, Irving H

2017-05-01

Tubuloglomerular feedback and the myogenic response are widely appreciated as important regulators of renal blood flow, but the role of the sympathetic nervous system in physiological renal blood flow control remains controversial. Where classic studies using static measures of renal blood flow failed, dynamic approaches have succeeded in demonstrating sympathetic control of renal blood flow under normal physiological conditions. This review focuses on transfer function analysis of renal pressure-flow, which leverages the physical relationship between blood pressure and flow to assess the underlying vascular control mechanisms. Studies using this approach indicate that the renal nerves are important in the rapid regulation of the renal vasculature. Animals with intact renal innervation show a sympathetic signature in the frequency range associated with sympathetic vasomotion that is eliminated by renal denervation. In conscious rabbits, this sympathetic signature exerts vasoconstrictive, baroreflex control of renal vascular conductance, matching well with the rhythmic, baroreflex-influenced control of renal sympathetic nerve activity and complementing findings from other studies employing dynamic approaches to study renal sympathetic vascular control. In this light, classic studies reporting that nerve stimulation and renal denervation do not affect static measures of renal blood flow provide evidence for the strength of renal autoregulation rather than evidence against physiological renal sympathetic control of renal blood flow. Thus, alongside tubuloglomerular feedback and the myogenic response, renal sympathetic outflow should be considered an important physiological regulator of renal blood flow. Clinically, renal sympathetic vasomotion may be important for solving the problems facing the field of therapeutic renal denervation. Copyright © 2016 Elsevier B.V. All rights reserved.

Leiomyosarcoma of the renal pelvis

Directory of Open Access Journals (Sweden)

Dhamne Sagar

2009-10-01

Full Text Available Leiomyosarcomas are rare malignant tumors of the kidney. They may arise from the renal capsule, renal vein, renal pelvic musculature or renal parenchyma. Renal pelvis is an uncommon site of occurrence, with around 10 cases reported in the literature so far. Here we present a 60-year-old male who presented with increased urinary frequency, lower limb weakness, anorexia and weight loss. Imaging showed a right renal mass. A renal cell carcinoma was suspected clinically. A right nephrectomy was performed, which showed a large circumscribed mass in the hilar region. Histology revealed a tumor mass arising from the renal pelvis. The tumor was composed of spindle cells arranged in fascicles. Immunohistochemistry showed tumor cells to be positive for smooth muscle actin (SMA and desmin (Des and negative for cytokeratin (CK, HMB 45, CD117 (C-kit, and CD34. That confirmed the diagnosis of leiomyosarcoma.

Renal and post-renal causes of acute renal failure in children

International Nuclear Information System (INIS)

Jamal, A.; Ramzan, A.

2004-01-01

Objective: To identify the causes of acute renal failure (ARF) in pediatric population along with the identification of the age and gender most affected by the failure. Subjects and Methods: The study included children under the age of 12 years who presented with signs and symptoms suggestive of ARF (oliguria/anuria, vomiting, acidotic breathing etc.) along with raised blood urea nitrogen (BUN) serum creatinine and metabolic acidosis as shown by arterial blood gases (ABGs). Patients were divided into two group on the basis of age; group A consisting of 0-2 years and group B from >2 years. Patients presenting with transient pre-renal azotaemia were excluded from the study. After providing initial emergency cover, detailed history, physical examination and investigations were carried out according to a proforma specially designed to ascertain the cause of ARF. Patients were managed for ARF as per standard recommendations and investigations completed or repeated as and when required. Results: A total of 119 patients with ARF were admitted in the ward over a period of two years constituting 1.36% of the total admissions and 16.39% of the admissions due to renal pathology. Mean age of presentation was 4.5 years 16.7% of the patients under the age of 5 years. Male predominance was noted in all ages with an overall male to female ratio of 2.3:1. Most common cause leading to ARF in younger age group was found to be hemolytic uremic syndrome [25(54.34%)] followed by septicemia [7(15.21 %)]. In older patients renal calculus disease was the most common [22(30.13%)] underlying pathology followed by pre-existing, undiagnosed chronic renal failure [16(21.91 %)]. Conclusion: ARF is fairly cotton in children especially under the age of 5 years showing a male predominance. More than 90% of the cases can be prevented by improving primary health care and by early and prompt treatment of infections. (author)

Dependence of renal blood flow on renal artery stenosis measured using CT angiography

Energy Technology Data Exchange (ETDEWEB)

Luedemann, Lutz [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Radiotherapy; Nafz, B.; Persson, P. [Charite - Universitaetsmedizin Berlin (Germany). Inst. for Vegetative Physiology; Elsner, F. [Krankenhaus am Urban, Berlin (Germany). Dept. of Anesthesiology; Grosse-Siestrup, C.; Meissler, M. [Charite - Universitaetsmedizin Berlin (Germany). Experimental Animal Unit; Gutberlet, M. [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Univ. Leipzig/ Leipzig Heart Center (Germany). Dept. of Diagnostic and Interventional Radiology; Lengsfeld, P.; Voth, M. [Bayer-Schering Pharma AG, Berlin (Germany). Global Medical Affairs Diagnostic Imaging

2011-03-15

The present study investigates the suitability of computed tomography angiography (CTA) depicting the degree of renal artery stenosis for estimating renal blood flow (RBF) in a kidney. Materials and Methods: We investigated renal artery stenosis assessment by CTA in eight adult female hybrid pigs with an ultrasound probe implanted at the renal vein for RBF measurement. An inflatable metal-free cuff was placed around the renal artery to control the RBF. The RBF was then reduced in four steps. For each reduced RBF value and baseline RBF, CTA with a reconstructed slice thickness of 0.625 mm was performed in the arterial phase following injection of 80 ml of nonionic intravenous contrast medium. The radius of the stenotic and non-stenotic renal artery segment was measured in the reconstructed images. Results: A significant linear correlation (p < 0.0001) was found between the relative apparent stenosis (calculated as the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment) and RBF. The linear regression yielded a slope of 0.57 and a y-axis of 24.1 %. A significant linear correlation (p < 0.0001) was also found between the relative true stenosis (the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment at baseline) and the RBF. The linear regression yielded a slope of 0.67 and a y-axis of 13.8 %. Conclusion: The results show that the relative stenosis apparent on CTA differs from the true degree of renal artery stenosis. Nevertheless, the degree of renal artery stenosis determined by CTA provides a reliable estimate of the resulting RBF reduction. (orig.)

Dependence of renal blood flow on renal artery stenosis measured using CT angiography

International Nuclear Information System (INIS)

Luedemann, Lutz; Nafz, B.; Persson, P.; Elsner, F.; Grosse-Siestrup, C.; Meissler, M.; Gutberlet, M.; Univ. Leipzig/ Leipzig Heart Center; Lengsfeld, P.; Voth, M.

2011-01-01

The present study investigates the suitability of computed tomography angiography (CTA) depicting the degree of renal artery stenosis for estimating renal blood flow (RBF) in a kidney. Materials and Methods: We investigated renal artery stenosis assessment by CTA in eight adult female hybrid pigs with an ultrasound probe implanted at the renal vein for RBF measurement. An inflatable metal-free cuff was placed around the renal artery to control the RBF. The RBF was then reduced in four steps. For each reduced RBF value and baseline RBF, CTA with a reconstructed slice thickness of 0.625 mm was performed in the arterial phase following injection of 80 ml of nonionic intravenous contrast medium. The radius of the stenotic and non-stenotic renal artery segment was measured in the reconstructed images. Results: A significant linear correlation (p < 0.0001) was found between the relative apparent stenosis (calculated as the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment) and RBF. The linear regression yielded a slope of 0.57 and a y-axis of 24.1 %. A significant linear correlation (p < 0.0001) was also found between the relative true stenosis (the ratio of the radii of the actual stenotic segment and a non-stenotic renal artery segment at baseline) and the RBF. The linear regression yielded a slope of 0.67 and a y-axis of 13.8 %. Conclusion: The results show that the relative stenosis apparent on CTA differs from the true degree of renal artery stenosis. Nevertheless, the degree of renal artery stenosis determined by CTA provides a reliable estimate of the resulting RBF reduction. (orig.)

Acute renal dysfunction in liver diseases

OpenAIRE

Betrosian, Alex P; Agarwal, Banwari; Douzinas, Emmanuel E

2007-01-01

Renal dysfunction is common in liver diseases, either as part of multiorgan involvement in acute illness or secondary to advanced liver disease. The presence of renal impairment in both groups is a poor prognostic indicator. Renal failure is often multifactorial and can present as pre-renal or intrinsic renal dysfunction. Obstructive or post renal dysfunction only rarely complicates liver disease. Hepatorenal syndrome (HRS) is a unique form of renal failure associated with advanced liver dise...

Assessment of renal function with 99Tcm-DTPA renal dynamic imaging in neonatal hydronephrosis

International Nuclear Information System (INIS)

Jiang Lixin; Guo Zongyuan; Wu Rongde; Yu Qihai; Liu Zhanfeng

2004-01-01

Objective: To assess the renal function in neonatal hydronephrosis with 99 Tc m -DTPA renal imaging. Methods: Eighteen unilateral hydronephrotic kidneys and 12 normal kidneys were studied by 99 Tc m -DTPA renal dynamic imaging , and glomerular filtration rate (GFR) quantitative analysis was also performed. Blood urea nitrogen (BUN), serum creatinine (SCr) and hemoglobin (Hb) were determined simultaneously and the correlations between GFR and each of these parameters were analyzed. Results: Positive correlation was discovered between GFR and Hb in neonates with moderate or severe hydronephrosis (r=0.414, 0.667, P 0.05). The renal function was decreased significantly in moderate and severe neonatal hydronephrosis (P 99 Tc m -DTPA renal dynamic imaging GFR is an ideal marker for estimating renal function in neonatal hydronephrosis; SCr could be a marker for renal damage especially in moderate and severe neonatal hydronephrosis; BUN could not be a marker for evaluating renal function in neonatal hydronephrosis. Neonates with hydronephrosis should be referred for surgical procedures as soon as possible in the early stage

Renal Function Outcomes for Multifocal Renal Neoplasms Managed by Radiofrequency Ablation

Energy Technology Data Exchange (ETDEWEB)

Gupta, Pushpender, E-mail: pugupta@wakehealth.edu; Allen, Brian C., E-mail: bcallen2@wakehealth.edu; Chen, Michael Y., E-mail: mchen@wakehealth.edu; Childs, David D., E-mail: dchilds@wakehealth.edu; Kota, Gopi, E-mail: gkota@wakehealth.edu; Zagoria, Ronald J., E-mail: rzagoria@wakehealth.edu [Wake Forest University School of Medicine, Department of Radiology (United States)

2013-10-15

Purpose: To evaluate renal function changes related to radiofrequency ablation (RFA) for the treatment of multifocal renal neoplasms. Methods: This is an institutional review board-approved, Health Insurance Portability and Accountability Act compliant retrospective study of all patients treated with computed tomography guided RFA for multifocal renal neoplasms at one institution. Fifty-seven subjects, mean age 70 (range 37-88) years, underwent RFA of 169 renal neoplasms (average size 2.0 cm). Subjects had between 2 and 8 (mean 2.96) neoplasms ablated. Estimated glomerular filtration rate (eGFR) was measured before and after RFA. Complications related to RFA were recorded. Results: eGFR decreased on average of 4.4 % per tumor treated and 6.7 % per ablation session (average 1.76 tumors treated per session). For subjects with the largest neoplasm measuring >3 cm, eGFR decreased an average of 14.5 % during the course of their treatment. If the largest neoplasm measured 2-3 cm, eGFR decreased an average of 7.7 %, and if the largest neoplasm measured <2 cm, eGFR decreased an average of 3.8 %. Subjects with reduced baseline renal function were more likely to have a greater decline in eGFR after RFA. There was a minor complication rate of 6.3 % (6 of 96 sessions), none of which required treatment, and a major complication rate of 4.2 % (4 of 96 sessions). Conclusion: RFA for the treatment of multifocal renal neoplasms results in mild decline of renal function.

Renal papillary necrosis

Science.gov (United States)

... asking your provider. Alternative Names Necrosis - renal papillae; Renal medullary necrosis Images Kidney anatomy Kidney - blood and urine flow References Bushinsky DA, Monk RD. Nephrolithiasis and nephrocalcinosis. ...

Imaging of renal osteodystrophy

Energy Technology Data Exchange (ETDEWEB)

Jevtic, V. E-mail: vladimir.jevtic@mf.uni-lj.si

2003-05-01

Chronic renal insufficiency, hemodialysis, peritoneal dialysis, renal transplantation and administration of different medications provoke complex biochemical disturbances of the calcium-phosphate metabolism with wide spectrum of bone and soft tissue abnormalities termed renal osteodystrophy. Clinically most important manifestation of renal bone disease includes secondary hyperparathyroidism, osteomalacia/rickets, osteoporosis, adynamic bone disease and soft tissue calcification. As a complication of long-term hemodialysis and renal transplantation amyloid deposition, destructive spondyloarthropathy, osteonecrosis, and musculoskeletal infections may occur. Due to more sophisticated diagnostic methods and more efficient treatment classical radiographic features of secondary hyperparathyroidism and osteomalacia/rickets are now less frequently seen. Radiological investigations play an important role in early diagnosis and follow-up of the renal bone disease. Although numerous new imaging modalities have been introduced in clinical practice (scintigraphy, CT, MRI, quantitative imaging), plain film radiography, especially fine quality hand radiograph, still represents most widely used examination.

Imaging of renal osteodystrophy

International Nuclear Information System (INIS)

Jevtic, V.

2003-01-01

Chronic renal insufficiency, hemodialysis, peritoneal dialysis, renal transplantation and administration of different medications provoke complex biochemical disturbances of the calcium-phosphate metabolism with wide spectrum of bone and soft tissue abnormalities termed renal osteodystrophy. Clinically most important manifestation of renal bone disease includes secondary hyperparathyroidism, osteomalacia/rickets, osteoporosis, adynamic bone disease and soft tissue calcification. As a complication of long-term hemodialysis and renal transplantation amyloid deposition, destructive spondyloarthropathy, osteonecrosis, and musculoskeletal infections may occur. Due to more sophisticated diagnostic methods and more efficient treatment classical radiographic features of secondary hyperparathyroidism and osteomalacia/rickets are now less frequently seen. Radiological investigations play an important role in early diagnosis and follow-up of the renal bone disease. Although numerous new imaging modalities have been introduced in clinical practice (scintigraphy, CT, MRI, quantitative imaging), plain film radiography, especially fine quality hand radiograph, still represents most widely used examination

CT findings of renal abscess

International Nuclear Information System (INIS)

Lee, Myung Jun; Kim, Mi Young; Woo, Jung Ju; Kim, Ho Kyun; Kim, Won Hong; Jeon, Jeong Dong; Jeon, Woo Ki; Han, Chang Yul

1996-01-01

The purpose of this study is to determine characteristic CT findings in renal abscess. Twenty cases of renal abscess were retrospectively analyzed for CT findings relating to the shape and extent of the abscess, change of nephrogram, peripheral rim enhancement, wedge-shaped enhancement on delayed scans, enlargement of the kidney involved and associated findings. Seven patients had a renal abscess at the right kidney, nine at the lift kidney and two bilaterally. The abscesses were round in 18 cases and finger-like in two. Rim enhancement around renal abscess was seen in four cases (20%). Changes in the nephrogram around the abscess were seen in 12 cases (60%). In all six patients who had undergone delayed postcontrast scans, wedge-shaped enhancement was shown around the abscess (100%). In the observation of the extent of renal abscesses, 14 cases were within the kidney, six cases extended the beyond renal capsule, and two were loculated in the renal fascia itself. Renal enlargement was seen in nine cases (45%). These results suggest that CT findings such as delayed wedge-shaped enhancement, change of nephrogram, peripheral rim enhancement, renal enlargement, and associated findings are valuable for diagnosis, and that CT also gives information concerning the extent, evolution and complication of a renal abscess

[Clinical study of influential factors on renal scarring after ESWL monotherapy for renal stone disease].

Science.gov (United States)

Ishito, Noritaka; Takamoto, Hitoshi; Kunitomi, Kimito; Satoh, Eiichi; Ishii, Ayano; Shiotuka, Youichi; Sako, Shinichi; Ohta, Naoki; Araki, Tohru

2002-11-01

ESWL is now widely used for the treatment of renal stone disease. Although ESWL has many advantages for patients' quality of life, few reports have demonstrated the long-term outcomes of the alterations of renal morphology after ESWL. We reported renal scarring after ESWL monotherapy in patients with renal calyceal stones. In this study, we evaluated a large series of patients' cohort treated at our institution, and assessed the causal effect of ESWL on the late occurrence of renal scar formation. ESWL was performed with EDAP (LT-01,02) that generates shock wave energy by piezoelectric discharge. We analyzed the records of 285 kidneys treated between Dec. 1986 and Nov. 1998. Renal scarring was noted in 44 kidneys and not in 241 kidneys with periodical ultrasonography. We compared the backgrounds of the two groups using chi-square or non-parametric analysis. The Kaplan-Meier method and Cox regression model determined the analysis of renal scar formation. Univariate and multiple regression analysis revealed that the total amount of ESWL emission and hyperuricemia independently affected the probability of renal scar formation. Over-emission of ESWL (over 10,000 shots) must be care for the prevention of renal scarring in patients with renal calyceal calculi, especially when associated with hyperuricemia. After ESWL, periodical checkups with ultrasonography will provide useful information for the clinical diagnosis of renal scarring.

Acute renal haemodynamic and renin-angiotensin system responses to graded renal artery stenosis in the dog.

Science.gov (United States)

Anderson, W P; Johnston, C I; Korner, P I

1979-01-01

1. The acute renal haemodynamic and renin-angiotensin system responses to graded renal artery stenosis were studied in chronically instrumented, unanaesthetized dogs. 2. Stenosis was induced over 30 sec by inflation of a cuff around the renal artery to lower distal pressure to 60, 40 or 20 mmHg, with stenosis maintained for 1 hr. This resulted in an immediate fall in renal vascular resistance, but over the next 5--30 min both resistance and renal artery pressure were restored back towards prestenosis values. Only transient increases in systemic arterial blood pressure and plasma renin and angiotensin levels were seen with the two milder stenoses. Despite restoration of renal artery pressure, renal blood flow remained reduced at all grades of stenosis. 3. Pre-treatment with angiotensin I converting enzyme inhibitor or sarosine1, isoleucone8 angiotensin II greatly attenuated or abolished the restoration of renal artery pressure and renal vascular resistance after stenosis, and plasma renin and angiotensin II levels remained high. Renal dilatation was indefinitely maintained, but the normal restoration of resistance and pressure could be simulated by infusing angiotensin II into the renal artery. 4. The effective resistance to blood flow by the stenosis did not remain constant but varied with changes in the renal vascular resistance. PMID:219182

Ramadan fasting and patients with renal diseases: A mini review of the literature.

Science.gov (United States)

Emami-Naini, Afsoon; Roomizadeh, Peyman; Baradaran, Azar; Abedini, Amin; Abtahi, Mohammad

2013-08-01

Fasting during the month of Ramadan is one of the five pillars of Islam. During this month, adult Muslims are obligated to refrain from eating and drinking from dawn to dusk. Although based on Islamic principles patients are exempted from fasting, each year, many Muslim patients express their willingness to observe the fast in Ramadan month to respect the cultural customs. There are concerns about the impact of fluid restriction and dehydration during Ramadan fasting for patients with renal diseases. In this study, we reviewed the PubMed, Google Scholar, EBSCO, SCIRUS, Embase, and DOAJ data sources to identify the published studies on the impact of Ramadan fasting on patients with renal diseases. Our review on published reports on renal transplant recipients revealed no injurious effect of Ramadan fasting for the renal graft function. Nearly all studies on this topic suggest that Ramadan fasting is safe when the function of the renal graft is acceptable and stable. Regarding the impact of Ramadan fasting on patients with chronic kidney disease, there is concern about the role of renal hypoperfusion in developing tubular cell injury. Finally, there is controversy between studies about the risk of dehydration in Ramadan in developing renal stones. There are uncertainties about the change in the incidence of renal colic in Ramadan month compared with the other periods of the year. Despite such discrepancies, nearly all studies are in agreement on consuming adequate amounts of water from dusk to dawn to reduce the risk of renal stone formation.

Value of renal cortical thickness as a predictor of renal function impairment in chronic renal disease patients

Directory of Open Access Journals (Sweden)

Samia Rafael Yamashita

2015-02-01

Full Text Available Objective: To determine the presence of linear relationship between renal cortical thickness, bipolar length, and parenchymal thickness in chronic kidney disease patients presenting with different estimated glomerular filtration rates (GFRs and to assess the reproducibility of these measurements using ultrasonography. Materials and Methods: Ultrasonography was performed in 54 chronic renal failure patients. The scans were performed by two independent and blinded radiologists. The estimated GFR was calculated using the Cockcroft-Gault equation. Interobserver agreement was calculated and a linear correlation coefficient (r was determined in order to establish the relationship between the different renal measurements and estimated GFR. Results: The correlation between GFR and measurements of renal cortical thickness, bipolar length, and parenchymal thickness was, respectively, moderate (r = 0.478; p < 0.001, poor (r = 0.380; p = 0.004, and poor (r = 0.277; p = 0.116. The interobserver agreement was considered excellent (0.754 for measurements of cortical thickness and bipolar length (0.833, and satisfactory for parenchymal thickness (0.523. Conclusion: The interobserver reproducibility for renal measurements obtained was good. A moderate correlation was observed between estimated GFR and cortical thickness, but bipolar length and parenchymal thickness were poorly correlated.

Cadmium and renal cancer

International Nuclear Information System (INIS)

Il'yasova, Dora; Schwartz, Gary G.

2005-01-01

Background: Rates of renal cancer have increased steadily during the past two decades, and these increases are not explicable solely by advances in imaging modalities. Cadmium, a widespread environmental pollutant, is a carcinogen that accumulates in the kidney cortex and is a cause of end-stage renal disease. Several observations suggest that cadmium may be a cause of renal cancer. Methods: We performed a systematic review of the literature on cadmium and renal cancer using MEDLINE for the years 1966-2003. We reviewed seven epidemiological and eleven clinical studies. Results: Despite different methodologies, three large epidemiologic studies indicate that occupational exposure to cadmium is associated with increased risk renal cancer, with odds ratios varying from 1.2 to 5.0. Six of seven studies that compared the cadmium content of kidneys from patients with kidney cancer to that of patients without kidney cancer found lower concentrations of cadmium in renal cancer tissues. Conclusions: Exposure to cadmium appears to be associated with renal cancer, although this conclusion is tempered by the inability of studies to assess cumulative cadmium exposure from all sources including smoking and diet. The paradoxical findings of lower cadmium content in kidney tissues from patients with renal cancer may be caused by dilution of cadmium in rapidly dividing cells. This and other methodological problems limit the interpretation of studies of cadmium in clinical samples. Whether cadmium is a cause of renal cancer may be answered more definitively by future studies that employ biomarkers of cadmium exposure, such as cadmium levels in blood and urine

Renal endothelial function and blood flow predict the individual susceptibility to adriamycin-induced renal damage

NARCIS (Netherlands)

Ochodnicky, Peter; Henning, Robert H.; Buikema, Hendrik; Kluppel, Alex C. A.; van Wattum, Marjolein; de Zeeuw, Dick; van Dokkum, Richard P. E.

2009-01-01

Susceptibility to renal injury varies among individuals. Previously, we found that individual endothelial function of healthy renal arteries in vitro predicted severity of renal damage after 5/6 nephrectomy. Here we hypothesized that individual differences in endothelial function in vitro and renal

[Hypertension and renal disease

DEFF Research Database (Denmark)

Kamper, A.L.; Pedersen, E.B.; Strandgaard, S.

2009-01-01

Renal mechanisms, in particular the renin-angiotensin system and renal salt handling, are of major importance in blood pressure regulation. Co-existence of hypertension and decreased renal function may be due to nephrosclerosis secondary to hypertension, or primary renal disease with secondary...... hypertension. Mild degrees of chronic kidney disease (CKD) can be detected in around 10% of the population, and detection is important as CKD is an important risk factor for atherosclerotic cardiovascular disease. Conversely, heart failure may cause an impairment of renal function. In chronic progressive...... nephropathy, effective blood pressure lowering is of paramount importance, and angiotensin converting enzyme inhibitors and angiotensin receptor blockers are agents of choice Udgivelsesdato: 2009/6/15...

Bilateral triple renal arteries

International Nuclear Information System (INIS)

Pestemalci, Turan; Yildiz, Yusuf Zeki; Yildirim, Mehmet; Mavi, Ayfer; Gumusburun, Erdem

2009-01-01

Knowledge of the variations of the renal artery has grown in importance with increasing numbers of renal transplants, vascular reconstructions and various surgical and radio logic techniques being performed in recent years. We report the presence of bilateral triple renal arteries, discovered on routine dissection of a male cadaver. On the right side, one additional renal artery originated from the abdominal aorta (distributed to superior pole of the kidney) and one other originated from the right common iliac artery (distributed to lower pole of the kidney). On the left side, both additional renal arteries originated from the abdominal aorta. Our observation has been compared with variations described in the literature and their clinical importance has been emphasized. (author)

Radiology of renal failure

International Nuclear Information System (INIS)

Griffiths, H.J.

1990-01-01

This book covers most aspects of imaging studies in patients with renal failure. The initial chapter provides basic information on contrast agents, intravenous urography, and imaging findings in the urinary tract disorders responsible for renal failure and in patients who have undergone transplantation. It illustrates common gastro-intestinal abnormalities seen on barium studies in patients with renal failure. It illustrates the cardiopulmonary complications of renal failure and offers advice for radiologic differentiation. It details different aspects of skeletal changes in renal failure, including a basic description of the pathophysiology of the changes; many excellent illustrations of classic bone changes, arthritis, avascular necrosis, and soft-tissue calcifications; and details of bone mineral analysis

Renal sinus fat invasion and tumoral thrombosis of the inferior vena cava-renal vein: only confined to renal cell carcinoma.

Science.gov (United States)

Acar, Turker; Harman, Mustafa; Guneyli, Serkan; Sen, Sait; Elmas, Nevra

2014-01-01

Epithelioid angiomyolipoma (E-AML), accounting for 8% of renal angiomyolipoma, is usually associated with tuberous sclerosis (TS) and demonstrates aggressive behavior. E-AML is macroscopically seen as a large infiltrative necrotic tumor with occasional extension into renal vein and/or inferior vena cava. However, without history of TS, renal sinus and venous invasion E-AML would be a challenging diagnosis, which may lead radiologists to misinterpret it as a renal cell carcinoma (RCC). In this case presentation, we aimed to report cross-sectional imaging findings of two cases diagnosed as E-AML and pathological correlation of these aforementioned masses mimicking RCC.

Diagnostic use of angiotensin converting enzyme (ACE)-inhibited renal scintigraphy in the identification of selective renal artery stenosis in the presence of multiple renal arteries: A case report

International Nuclear Information System (INIS)

Morton, K.A.; Rose, S.C.; Haakenstad, A.O.; Handy, J.E.; Scuderi, A.J.; Datz, F.L.

1990-01-01

In patients with renovascular hypertension, it is unknown whether the angiotensin converting enzyme-(ACE) inhibited renal scan will identify stenosis of a segmental branch of a single renal artery or of an accessory artery where multiple renal arteries are present. Since multiple renal arteries may be present in approximately 25% of all individuals, it will be important to establish whether the ACE-inhibited renal scan is useful in this population. We report a case of stenosis involving a renal artery in a patient with multiple renal arteries, successfully identified by ACE-inhibited renal scintigraphy

Renal inflammatory myofibroblastic tumor

DEFF Research Database (Denmark)

Heerwagen, S T; Jensen, C; Bagi, P

2007-01-01

Renal inflammatory myofibroblastic tumor (IMT) is a rare soft-tissue tumor of controversial etiology with a potential for local recurrence after incomplete surgical resection. The radiological findings in renal IMT are not well described. We report two cases in adults with a renal mass treated...

Does complete renal denervation translate into superior clinical outcomes? Lessons learned from denervation of accessory renal arteries

OpenAIRE

Mendelsohn, Farrell O.

2014-01-01

Pre-clinical studies of renal denervation would suggest that the extent of renal nerve injury correlates with outcomes. The “completeness” of renal nerve injury following renal denervation correlates with treatment-based variables such as the depth of ablation, the number of ablations along the length of the artery, and the number of renal arteries successfully ablated. Renal denervation techniques targeting only main renal arteries may lead to suboptimal results in patients with accessory re...

Renal haemodynamic in essential hypertension assessed by 133Xe washout and selective renal angiography

International Nuclear Information System (INIS)

Gatta, A.; Merkel, C.; Pessina, A.C.; Milani, L.; Sacerdoti, D.; Zuin, R.

1982-01-01

The renal and intrarenal haemodynamic pattern in 17 patients with essential hypertension of different severity and duration was studied by means of the 133-Xenon washout technique and the selective renal angiography. The mean and the cortical renal blood flows were on average significantly decreased as compared to the controls. A good agreement was found between the reduction in renal perfusion and the degree of vascular abnormalities as shown by angiography; on the contrary no correlation was found between the impairment in renal blood flow and the degree and/or duration of hypertension

Exaggerated natriuresis and lithium clearance in spontaneously hypertensive rats

DEFF Research Database (Denmark)

Holstein-Rathlou, N H; Kanters, J K; Leyssac, P P

1988-01-01

Since hypertension is associated with changes in the handling of various cations (including sodium and lithium) across the cell membrane, the present study investigated the validity of the lithium clearance method in hypertension by comparing two measures of proximal reabsorption. Thus, fractional...... lithium excretion and transit time (TT)-occlusion time (OT; e-TT/T) were determined successively in the same spontaneously hypertensive rat (SHR, Okamoto strain). The rats were examined both before and after an acute saline load. The results show that the lithium clearance method can be used...... for the determination of proximal reabsorption in SHR. Utilizing the lithium clearance method, the changes in renal sodium handling underlying the exaggerated natriuresis were investigated in unanaesthetized catheterized rats. It was found that the exaggerated natriuresis was associated with an increased output from...

Escherichia coli Shiga Toxin Mechanisms of Action in Renal Disease

Directory of Open Access Journals (Sweden)

Tom G. Obrig

2010-12-01

Full Text Available Shiga toxin-producing Escherichia coli is a contaminant of food and water that in humans causes a diarrheal prodrome followed by more severe disease of the kidneys and an array of symptoms of the central nervous system. The systemic disease is a complex referred to as diarrhea-associated hemolytic uremic syndrome (D+HUS. D+HUS is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. This review focuses on the renal aspects of D+HUS. Current knowledge of this renal disease is derived from a combination of human samples, animal models of D+HUS, and interaction of Shiga toxin with isolated renal cell types. Shiga toxin is a multi-subunit protein complex that binds to a glycosphingolipid receptor, Gb3, on select eukaryotic cell types. Location of Gb3 in the kidney is predictive of the sites of action of Shiga toxin. However, the toxin is cytotoxic to some, but not all cell types that express Gb3. It also can cause apoptosis or generate an inflammatory response in some cells. Together, this myriad of results is responsible for D+HUS disease.

99mtechnetium-dimercapto-succinic acid renal scanning and excretory urography in diagnosis of renal scars in children

International Nuclear Information System (INIS)

McLorie, G.A.; Aliabadi, H.; Churchill, B.M.; Ash, J.M.; Gilday, D.L.

1989-01-01

We compared the ability of excretory urography (without tomography) and 99mtechnetium-dimercapto-succinic acid renal scanning to detect renal scars in 32 children with primary vesicoureteral reflux. These children did not have hydronephrosis, renal failure or urinary tract obstruction. In all cases both studies were conducted within a 10-month period. The findings from both modalities were in agreement for 51 of the 64 renal units evaluated (80%). Evaluation of the excretory urogram indicated 6 cases of diffuse and 2 of focal scarring that were not detected by evaluation of the renal scan. The sensitivity of excretory urography to detect renal scars was 84% and the specificity was 83%. The 99mtechnetium-dimercapto-succinic acid renal scan showed 5 cases of focal renal scarring not detected by excretory urography. The sensitivity of the renal scan to detect renal scars was 77% and the specificity was 75%. We conclude that neither study alone could effectively replace the other for the detection of renal scars, and recommend that both be included in the initial evaluation and followup of patients with renal scars

Evaluation of allograft perfusion by radionuclide first-pass study in renal failure following renal transplantation

International Nuclear Information System (INIS)

Baillet, G.; Ballarin, J.; Urdaneta, N.; Campos, H.; Vernejoul, P. de; Fermanian, J.; Kellershohn, C.; Kreis, H.

1986-01-01

To assess the diagnostic value of indices measured on a first-pass curve, we performed 72 radionuclide renal first-pass studies (RFP) in 21 patients during the early weeks following renal allograft transplantation. The diagnosis was based on standard clinical and biochemical data and on fine needle aspiration biopsy (FNAB) of the transplant. Aortic and renal first-pass curves were filtered using a true low-pass filter and five different indices of renal perfusion were computed, using formulae from the literature. Statistical analysis performed on the aortic and renal indices indicated excellent reproducibility of the isotopic study. Although renal indices presented a rather large scatter, they all discriminated well between normal and rejection. Three indices have a particularly good diagnostic value. In the discrimination between rejection and Acute Tubular Necrosis (ATN), only one index gave satisfying results. The indices, however, indicate that there are probably ATN with an alternation of renal perfusion and rejection episodes where perfusion is almost intact. We conclude that radionuclide first-pass study allows accurate and reproducible quantitation of renal allograft perfusion. The measured parameters are helpful to follow up the course of a post-transplantation renal failure episode and to gain more insight into renal ischemia following transplantation. (orig.)

CT features of renal infarction

International Nuclear Information System (INIS)

Suzer, Okan; Shirkhoda, Ali; Jafri, S. Zafar; Madrazo, Beatrice L.; Bis, Kostaki G.; Mastromatteo, James F.

2002-01-01

Purpose: To demonstrate the different patterns of renal infarction to avoid pitfalls. To present 'flip-flop enhancement' pattern in renal infarction. Materials and methods: Retrospective review of a total of 41 renal infarction in 37 patients were done. These patients underwent initial CT and the diagnosis of renal infarction was confirmed with either follow up CT or at surgery. Results: Twenty-three patients had wedge-shaped focal infarcts, nine patients had global and five patients had multifocal infarcts of the kidneys. Cortical rim sign was seen predominantly with global infarcts. In five patients, a 'flip-flop enhancement' pattern was observed. In two patients, planned renal biopsies due to tumefactive renal lesions were cancelled because of 'flip-flop enhancement' pattern on follow up CTs. Conclusion: Although most of our cases were straightforward for the diagnosis of renal infarction, cases with tumefactive lesions and global infarctions without the well-known cortical rim sign were particularly challenging. We describe a new sign, flip-flop enhancement pattern, which we believe solidified the diagnosis of renal infarction in five of our cases. The authors recommend further investigations for association of flip-flop enhancement and renal infarction

[Small renal mass].

Science.gov (United States)

Prokofiev, D; Kreutzer, N; Kress, A; Wissing, F; Pfeifer, H; Stolzenburg, J-U; Dietel, A; Schwalenberg, T; Do, M; Truß, M C

2012-10-01

The frequent application of ultrasound and radiological imaging for non-urological indications in recent years has resulted in an increase in the diagnosis of small renal masses. The treatment options for patients with a small renal mass include active surveillance, surgery (both open and minimally invasive) as well as ablative techniques. As there is a risk for metastatic spread even in small renal masses surgical extirpation remains the treatment of choice in most patients. Ablative procedures, such as cryoablation and radiofrequency ablation are appropriate for old and multi-morbid patients who require active treatment of a small renal mass. Active surveillance is an alternative for high-risk patients. Meticulous patient selection by the urologist and patient preference will determine the choice of treatment option in the future.

Water-soluble dietary fibers and cardiovascular disease.

Science.gov (United States)

Theuwissen, Elke; Mensink, Ronald P

2008-05-23

One well-established way to reduce the risk of developing cardiovascular disease (CVD) is to lower serum LDL cholesterol levels by reducing saturated fat intake. However, the importance of other dietary approaches, such as increasing the intake of water-soluble dietary fibers is increasingly recognized. Well-controlled intervention studies have now shown that four major water-soluble fiber types-beta-glucan, psyllium, pectin and guar gum-effectively lower serum LDL cholesterol concentrations, without affecting HDL cholesterol or triacylglycerol concentrations. It is estimated that for each additional gram of water-soluble fiber in the diet serum total and LDL cholesterol concentrations decrease by -0.028 mmol/L and -0.029 mmol/L, respectively. Despite large differences in molecular structure, no major differences existed between the different types of water-soluble fiber, suggesting a common underlying mechanism. In this respect, it is most likely that water-soluble fibers lower the (re)absorption of in particular bile acids. As a result hepatic conversion of cholesterol into bile acids increases, which will ultimately lead to increased LDL uptake by the liver. Additionally, epidemiological studies suggest that a diet high in water-soluble fiber is inversely associated with the risk of CVD. These findings underlie current dietary recommendations to increase water-soluble fiber intake.

An experimental study on renal arterial and parenchymal change caused by selective renal infusion of epinephrine

International Nuclear Information System (INIS)

Jeon, Seok Chol; Yeon, Kyung Mo; Han, Man Chung

1981-01-01

Selective infusion of the epinephrine into the renal artery has been used in the field of the diagnostic and the therapeutic radiology for correct diagnosis and effective treatment, respectively. However, administration of overdose of epinephrine may cause serious complication, renal infarction. The study was undertaken to evaluate the sequential change of renal arterial constrictive effect of selective infusion of epinephrine into renal artery and to determine the critical doses of epinephrine producing irreversible renal infarct. A total of 25 rabbits are used, which are divided into 5 groups. Under the general anesthesia is made the selective infusion of various doses of epinephrine into the right renal artery of the rabbits. At the various time interval during and after the epinephrine infusion, renal angiography was done, and 24 hrs. later, gross and microscopic findings of the kidney were observed. The results are as follows; 1. Vasoconstriction of renal artery occurred within 2 mins. infusion, and maximum effect within 5 mins. 2. It seems that there is correlation between the amount of infused epinephrine and the time taken to recover from constriction of renal artery. 3. When epinephrine is infused into the renal artery in the rate of 1 ug/min., renal infarct is not noticed below the level of 10 mins., but correlation between the amount of infused epinephrine and the frequency of renal infarct occurs above 20 mins. infusion

Chemical renal denervation in the rat.

Science.gov (United States)

Consigny, Paul M; Davalian, Dariush; Donn, Rosy; Hu, Jie; Rieser, Matthew; Stolarik, Deanne

2014-02-01

The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose-response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography-mass spectrometry. Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10(-5) M through 10(-2) M paclitaxel. We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

Interactive effect of aging and local muscle heating on renal vasoconstriction during isometric handgrip.

Science.gov (United States)

Kuipers, Nathan T; Sauder, Charity L; Kearney, Matthew L; Ray, Chester A

2009-08-01

The purpose of the study was to determine the interactive effect of aging and forearm muscle heating on renal vascular conductance and muscle sympathetic nerve activity (MSNA) during ischemic isometric handgrip. A tube-lined, water-perfused sleeve was used to heat the forearm in 12 young (27 +/- 1 yr) and 9 older (63 +/- 1 yr) subjects. Ischemic isometric handgrip was performed before and after heating. Muscle temperature (intramuscular thermistor) was 34.3 +/- 0.2 and 38.7 +/- 0.1 degrees C during normothermia and heating, respectively. At rest, heating had no effect on renal blood velocity (Doppler ultrasound) or renal vascular conductance in either group (young, n = 12; older, n = 8). Heating compared with normothermia caused a significantly greater increase in renal vasoconstriction during exercise and postexercise muscle ischemia (PEMI) in both groups. However, the increase in renal vasoconstriction during heating was greater in the older compared with the young subjects (18 +/- 3 vs. 8 +/- 3%). During handgrip, heating elicited greater increases in MSNA responses in the older group (young, n = 12; older, n = 6), whereas no statistical difference was observed between groups during PEMI. In summary, aging augments renal vascular responses to ischemic isometric handgrip during heating of the exercising muscle. The greater renal vasoconstriction was associated with augmented MSNA in the older subjects.

Infarction of renal transplant with extrarenal excretion of Tc-99m MAG3 demonstrated by renal scintigraphy

International Nuclear Information System (INIS)

Lim, Seok Tae; Kim, Min Woo; Sohn, Myung Hee

2003-01-01

A 38-year-old woman with end stage renal disease received a living related donor-renal transplant to the right iliac fossa. She developed anuria a week later. Tc-99m MAG 3 renal scintigraphy demonstrated no perfusion, uptake, or excretion of the radioactive tracer from the renal transplant. The expected area of the renal allograft appeared as a photopenic area with increased rim activity. The gallbladder and bowel activities were observed on delayed images at 24 hours. There was no blood flow within the renal artery on renal doppler examination. This case shows total absence of perfusion and function in the infarcted renal transplant with extrarenal excretion of Tc-99m MAG 3 caused by acute renal artery thrombosis

Intra-renal localised reno-renal collaterals in the dog after tying of the main renal artery

International Nuclear Information System (INIS)

Rosenbusch, G.; Vincent, J.; Douveren, W. van; Sktonicki, S.; Arts, T.H.M.; Katholieke Univ. Nijmegen; Katholieke Univ. Nijmegen

1984-01-01

In 7 kidneys of 6 dogs one of the main stem of the renal artery was ligated. The development of the renorenal collaterals could be followed in 5, as two dogs died after the operation. In all cases intrarenal collaterals could be demonstrated, even in the postoperative dead dogs. The vessels responsible for the collateral circulation are preformed interarterial anastomoses, belonging to the extraglomerular arterial system. From the results of these and former experimental studies it can be concluded, that the renal artery of the dog when entering the renal sinus cannot be regarded as an anatomic, but at most as a functional end artery. (orig.) [de

Intra-renal localised reno-renal collaterals in the dog after tying of the main renal artery

Energy Technology Data Exchange (ETDEWEB)

Rosenbusch, G.; Vincent, J.; Douveren, W. van; Sktonicki, S.; Arts, T.H.M.

1984-01-01

In 7 kidneys of 6 dogs one of the main stem of the renal artery was ligated. The development of the renorenal collaterals could be followed in 5, as two dogs died after the operation. In all cases intrarenal collaterals could be demonstrated, even in the postoperative dead dogs. The vessels responsible for the collateral circulation are preformed interarterial anastomoses, belonging to the extraglomerular arterial system. From the results of these and former experimental studies it can be concluded, that the renal artery of the dog when entering the renal sinus cannot be regarded as an anatomic, but at most as a functional end artery.

Influence of renal shielding on the incidence of late renal dysfunction associated with bone marrow transplantation

International Nuclear Information System (INIS)

Lawton, C.A.; Ash, R.C.; Murray, K.J.; Cohon, E.P.; Barher-Derus, S.W.; Moulder, J.E.

1991-01-01

This paper reports that late renal dysfunction following bone marrow transplantation has been described by a number of centers including the authors own. Total body irradiation seems to play a major causative role. In an effort to decrease the incidence of this renal toxicity, the authors have added customized partial transmission renal blocking to their total body irradiation regimen. The purpose of this study is to evaluate the effect of the renal blocking. The authors total body irradiation dose is 14 Gy. With the shielding used, the kidneys received approximately 12 Gy. Fifty-five adult patients have received total body irradiation with this renal shielding, compared with 73 adult patients who were treated without renal shielding. Eighteen percent (13 of 73) of patients who did not have renal shielding compared with only 7% (4 of 55) of patients with renal shielding have developed late renal dysfunction. Median follow-up in the non-blocked patients is 451 days after transplantation versus 282 days for the blocked patients

Accessory renal arteries: Prevalence in resistant hypertension and an important role in nonresponse to radiofrequency renal denervation

Energy Technology Data Exchange (ETDEWEB)

VonAchen, Paige [Minneapolis Heart Institute and Foundation at Abbott Northwestern Hospital, Minneapolis, MN (United States); Hamann, Jason [Boston Scientific Corporation, Maple Grove, MN (United States); Houghland, Thomas; Lesser, John R.; Wang, Yale; Caye, David; Rosenthal, Kristi; Garberich, Ross F. [Minneapolis Heart Institute and Foundation at Abbott Northwestern Hospital, Minneapolis, MN (United States); Daniels, Mary [Vital Images/Toshiba, Minnetonka, MN (United States); Schwartz, Robert S., E-mail: rss@rsschwartz.com [Minneapolis Heart Institute and Foundation at Abbott Northwestern Hospital, Minneapolis, MN (United States)

2016-10-15

Objective: The aim of this study was to understand the role of accessory renal arteries in resistant hypertension, and to establish their role in nonresponse to radiofrequency renal denervation (RDN) procedures. Background: Prior studies suggest a role for accessory renal arteries in hypertensive syndromes, and recent clinical trials of renal denervation report that these anomalies are highly prevalent in resistant hypertension. This study evaluated the relationships among resistant hypertension, accessory renal arteries, and the response to radiofrequency (RF) renal denervation. Methods: Computed Tomography Angiography (CTA) and magnetic resonance imaging (MRI) scans from 58 patients with resistant hypertension undergoing RF renal denervation (RDN) were evaluated. Results were compared with CT scans in 57 healthy, normotensive subjects undergoing screening as possible renal transplant donors. All scans were carefully studied for accessory renal arteries, and were correlated with long term blood pressure reduction. Results: Accessory renal arteries were markedly more prevalent in the hypertensive patients than normotensive renal donors (59% vs 32% respectively, p = 0.004). RDN had an overall nonresponse rate of 29% (response rate 71%). Patients without accessory vessels had a borderline higher response rate to RDN than those with at least one accessory vessel (83% vs 62% respectively, p = 0.076) and a higher RDN response than patients with untreated accessory arteries (83% vs 55%; p = 0.040). For accessory renal arteries and nonresponse, the sensitivity was 76%, specificity 49%, with positive and negative predictive values 38% and 83% respectively. Conclusions: Accessory renal arteries were markedly over-represented in resistant hypertensives compared with healthy controls. While not all patients with accessory arteries were nonresponders, nonresponse was related to both the presence and non-treatment of accessory arteries. Addressing accessory renal arteries in

Accessory renal arteries: Prevalence in resistant hypertension and an important role in nonresponse to radiofrequency renal denervation

International Nuclear Information System (INIS)

VonAchen, Paige; Hamann, Jason; Houghland, Thomas; Lesser, John R.; Wang, Yale; Caye, David; Rosenthal, Kristi; Garberich, Ross F.; Daniels, Mary; Schwartz, Robert S.

2016-01-01

Objective: The aim of this study was to understand the role of accessory renal arteries in resistant hypertension, and to establish their role in nonresponse to radiofrequency renal denervation (RDN) procedures. Background: Prior studies suggest a role for accessory renal arteries in hypertensive syndromes, and recent clinical trials of renal denervation report that these anomalies are highly prevalent in resistant hypertension. This study evaluated the relationships among resistant hypertension, accessory renal arteries, and the response to radiofrequency (RF) renal denervation. Methods: Computed Tomography Angiography (CTA) and magnetic resonance imaging (MRI) scans from 58 patients with resistant hypertension undergoing RF renal denervation (RDN) were evaluated. Results were compared with CT scans in 57 healthy, normotensive subjects undergoing screening as possible renal transplant donors. All scans were carefully studied for accessory renal arteries, and were correlated with long term blood pressure reduction. Results: Accessory renal arteries were markedly more prevalent in the hypertensive patients than normotensive renal donors (59% vs 32% respectively, p = 0.004). RDN had an overall nonresponse rate of 29% (response rate 71%). Patients without accessory vessels had a borderline higher response rate to RDN than those with at least one accessory vessel (83% vs 62% respectively, p = 0.076) and a higher RDN response than patients with untreated accessory arteries (83% vs 55%; p = 0.040). For accessory renal arteries and nonresponse, the sensitivity was 76%, specificity 49%, with positive and negative predictive values 38% and 83% respectively. Conclusions: Accessory renal arteries were markedly over-represented in resistant hypertensives compared with healthy controls. While not all patients with accessory arteries were nonresponders, nonresponse was related to both the presence and non-treatment of accessory arteries. Addressing accessory renal arteries in

Renal Sinus Fat Invasion and Tumoral Thrombosis of the Inferior Vena Cava-Renal Vein: Only Confined to Renal Cell Carcinoma

Directory of Open Access Journals (Sweden)

Turker Acar

2014-01-01

Full Text Available Epithelioid angiomyolipoma (E-AML, accounting for 8% of renal angiomyolipoma, is usually associated with tuberous sclerosis (TS and demonstrates aggressive behavior. E-AML is macroscopically seen as a large infiltrative necrotic tumor with occasional extension into renal vein and/or inferior vena cava. However, without history of TS, renal sinus and venous invasion E-AML would be a challenging diagnosis, which may lead radiologists to misinterpret it as a renal cell carcinoma (RCC. In this case presentation, we aimed to report cross-sectional imaging findings of two cases diagnosed as E-AML and pathological correlation of these aforementioned masses mimicking RCC.

Renal artery pseudoaneurysm