Effects of alterations in urine flow rate on prostaglandin E excretion in conscious dogs

1980 ◽  
Vol 238 (2) ◽  
pp. F107-F111 ◽  
Author(s):  
M. A. Kirschenbaum ◽  
E. R. Serros
Keyword(s):  
Flow Rate ◽  
Plasma Osmolality ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Prostaglandin E ◽  
Flow Rates ◽  
Water Loading ◽  
Receptor Assay ◽  
Excretion Rates ◽  
Previous Group

The relationships between urinary prostaglandin E excretion and urine flow rate were evaluated in 11 conscious mongrel dogs during antidiuresis, maximal water loading, vasopressin administration during maximal water loading, and mannitol infusion. Urine flow rates between 0.21 and 15.1 ml/min were achieved. Urinary prostaglandin E excretion rates, determined by a membrane receptor assay, varied directly with urine flow rates (r = 0.908). Vasopressin administration (34--540 microU . kg-1 . min-1) resulted in a fall, rather than the expected rise, in urinary prostaglandin E excretion. When the concentration of prostaglandin E in the urine was plotted against urine flow rate, the demonstrated relationship appeared most consistent with passive diffusion. Mannitol infusion increased urine flow rates to levels comparable to the levels seen with maximal water loading but did not result in a fall in plasma osmolality. Urinary prostaglandin E excretion rates, however, were not distinguishable from those in the previous group. These data demonstrate that urinary prostaglandin E excretion rates are determined, to a great extent, by urine flow rate and that the significance of the interpretation of elevated excretion levels of these lipids in diuretic states may have to be reevaluated.

Prostaglandin-dependent polyuria in hypercalcemia

1981 ◽  
Vol 241 (3) ◽  
pp. F224-F230 ◽  
Author(s):  
E. R. Serros ◽  
M. A. Kirschenbaum
Keyword(s):  
Flow Rate ◽  
Plasma Osmolality ◽  
Prostaglandin Synthesis ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Prostaglandin E ◽  
Inhibition Of Prostaglandin Synthesis ◽  
Final Group ◽  
Thirst Mechanism

The present experiments examined the role of prostaglandin biosynthesis in the increase in urine flow rate seen in rats with hypercalcemia induced by the administration of 1,25-dihydroxycholecalciferol. In a first group, rats receiving the vitamin D metabolite developed hypercalcemia, polyuria, and increased urine prostaglandin E excretion. Indomethacin resulted in a fall in urine prostaglandin E excretion. A second group was fluid restricted to ascertain whether increased thirst could be an etiologic mechanism of the polyuria. This resulted in a trivial fall in urine flow rate despite a fall in body weight and a rise in both urine and plasma osmolality. In a final group, prostaglandin inhibition restored the vasopressin sensitivity of the hypercalcemic kidney. Accordingly, the polyuria seen in hypercalcemic rats after the administration of 1,25-dihydroxycholecalciferol is associated with an increase in urine prostaglandin E excretion and can be reversed by inhibition of prostaglandin synthesis. In addition, this polyuria can occur independent of the thirst mechanism. Finally, there is evidence that the vasopressin resistance of the hypercalcemic kidney could be reversed by prostaglandin inhibition.

Active and Inactive Urinary Kallikrein in Man: Effects of Diuresis and Antidiuresis

1990 ◽  
Vol 79 (2) ◽  
pp. 117-121 ◽  
Author(s):  
Derek G. Waller ◽  
Satvinder S. Bhatia ◽  
Sara K. Campbell ◽  
Janet D. M. Albano ◽  
J. Gavin B. Millar
Keyword(s):  
Flow Rate ◽  
Arginine Vasopressin ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Urinary Kallikrein ◽  
Flow Rates ◽  
Water Load ◽  
Water Loading ◽  
Regression Relationship ◽  
Antidiuretic Action

1. The urinary excretion of active and inactive kallikrein was studied in volunteers during diuresis induced by water loading or oral frusemide and during antidiuresis induced by desamino-d-arginine-vasopressin. 2. During acute oral water loading, excretion of active kallikrein was unchanged, despite high urine flow rates and low urine osmolalities being achieved. Excretion of inactive kallikrein correlated with the urine flow rate. 3. After desamino-d-arginine-vasopressin in eight water-loaded and six normally hydrated subjects, excretion of inactive kallikrein also correlated with the urine flow rate. There were no significant changes in the excretion of active kallikrein. 4. After frusemide there was a small transient increase in excretion of active kallikrein 1–2 h after dosing which coincided with the maximum diuresis and natriuresis. Excretion of inactive kallikrein again correlated with urine flow rate but the regression relationship between the two variables was different for water-load-induced and frusemide-induced diuresis. 5. These studies do not support a role for urinary kallikrein in the modulation of the antidiuretic action of vasopressin, but suggest that it may contribute to the natriuretic action of frusemide.

Renal Function in Unanaesthetized River Lampreys (Lampetra FluviatilisL.): Effects of Anaesthesia, Temperature and Environmental Salinity

1983 ◽  
Vol 105 (1) ◽  
pp. 351-362 ◽  
Author(s):  
A. J. MCVICAR ◽  
J. C. RANKIN
Keyword(s):  
Renal Function ◽  
Flow Rate ◽  
Ventilation Rate ◽  
Urine Flow ◽  
The Body ◽  
Urine Flow Rate ◽  
Flow Rates ◽  
Gill Ventilation ◽  
Daily Excretion ◽  
The Mean

1. Improved estimates of urine flow rates of lampreys in various salinities were obtained by the collection of urine for periods of up to 48 h from minimally-stressed, unanaesthetized fish, following catheterization of the urinogenital papilla. 2. The mean urine flow rate of freshwater lampreys was 200.7 ±14.3 ml kg−1 day−1. 3. Urine flow in freshwater lampreys was correlated with spontaneous changes in gill ventilation rate. MS222 anaesthesia reduced both ventilation and urine flow rates, but pronounced effects were only observed at concentrations greater than those needed to induce light anaesthesia (50–55 mg 1−1). Urine flow rate in unanaesthetized fish was extremely sensitive to rapid (6°Ch−1) changes in temperature and Q10 (6–16°C) was approximately 5. 4. Urine flow rate decreased rapidly as the osmotic difference between the body fluids and environment approached zero, and the rate of flow in 30% seawater lampreys was only 7.6% that of freshwater fish. 5. There was no evidence for an effect of environmental calcium concentration on branchial osmotic permeability. 6. Extensive tubular reabsorption of ions occurred in freshwater lampreys. The total daily excretion rate of sodium ions generally decreased in salinities hyperosmotic to the plasma, indicating enhanced reabsorption, but secretion of magnesium and sulphate ions was greatly increased. Urine osmolarity was significantly increased in lampreys in hyperosmotic salinities. 7. Present data compare favourably with data obtained previously from anaesthetized animals, indicating that renal function in lampreys is not significantly impaired by light MS222 anaesthesia.

scholarly journals A Simple Equation to Estimate Urinary Flow Rate Using Urine Creatinine

2020 ◽  
Vol 51 (5) ◽  
pp. 395-400
Author(s):  
Luke Webster ◽  
Brett Larive ◽  
Jennifer Gassman ◽  
Alexander Bullen ◽  
Steven D. Weisbord ◽  
...  
Keyword(s):  
Flow Rate ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Simple Equation ◽  
Urinary Flow ◽  
Urine Creatinine ◽  
Highly Correlated ◽  
New Equation ◽  
Excretion Rates ◽  
Practice Methods

Background: Accurate assessment of urine flow remains challenging in both inpatient and outpatient settings. We hypothesized we could derive an equation that would accurately estimate urine flow rate (eV) through derivation from other existing equations commonly used in nephrology clinical practice. Methods: The eV equation was derived using the Cockcroft-Gault and the measured creatinine clearance (CrCl = UCrV/PCr) equations. Within the African American Study of Kidney Disease and Hypertension (AASK; n = 570) and COMBINE (n = 133) clinical trials, we identified participants with concordant estimated and measured creatinine excretion rates to define a subset with highly accurate 24-h urine collections, to assure a reliable gold standard. We then compared eV to measured 24-h urine flow rates in these trials. Results: In AASK, we found a high correlation between eV and measured urine flow rate (V; r = 0.91, p < 0.001); however, Bland-Altman plots showed that eV was 9.5 mL/h lower than V, on average. Thus, we added a correction factor to the eV equation and externally validated the new equation in COMBINE. eV and V were again highly correlated (r = 0.91, p < 0.001), and bias was improved (mean difference 5.3 mL/h). Overall, 80% of individuals had eV that was within 20% of V. Conclusions: A simple equation using urine creatinine, demographics, and body weight can accurately predict urine flow rate and may have clinical utility in situations where it is difficult to accurately measure the urine flow rate.

Renal melatonin excretion in sheep is enhanced by water diuresis

1993 ◽  
Vol 138 (3) ◽  
pp. 445-450 ◽  
Author(s):  
M. Valtonen ◽  
J. T. Laitinen ◽  
L. Eriksson
Keyword(s):  
Water Balance ◽  
Flow Rate ◽  
Plasma Osmolality ◽  
Urine Osmolality ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Urine Collection ◽  
Pineal Function ◽  
Fluid Load ◽  
Normal Water

ABSTRACT Diurnal variation in blood melatonin levels and renal melatonin excretion was monitored in five ewes by blood sampling and quantitative urine collection at 2-h intervals. A typical secretory pattern of melatonin was seen both in blood and urine levels and in the renal excretion of melatonin. Serum melatonin levels increased from daytime values of approximately 200 pmol/l to a mean of 800 pmol/l during darkness. Urine flow rate and urine osmolality did not show any clear diurnal rhythm. To examine whether urine flow rate affects renal melatonin excretion at night, urine was collected in three consecutive 30-min fractions, and blood was sampled in the middle of each urine collection period when the sheep were in normal water balance or after hydration. Hydration increased urine flow rate over sixfold and decreased urine osmolality well below plasma osmolality. Glomerular filtration rate, measured as creatinine clearance, did not change. Serum melatonin concentrations did not differ between hydrated and non-hydrated sheep. However, urinary melatonin excretion was 1·1 ± 0·3 (s.e.m.) pmol/min at midnight in normal water balance, and significantly higher (2·6 ± 0·4 pmol/min) in the hydrated state. In this study, the validity of urinary melatonin determinations as an indicator of pineal function was confirmed in normal water balance. In addition, our results suggest that a high tubular fluid load during diuresis increases urinary melatonin excretion because of decreased tubular reabsorption. This means that urine flow rate should be taken into consideration in studies where urinary melatonin levels are used as an index of production of the indole by the pineal gland. Journal of Endocrinology (1993) 138, 445–450

The Role of Prostaglandins in Glucagon-Induced Natriuresis

1980 ◽  
Vol 58 (5) ◽  
pp. 393-401 ◽  
Author(s):  
M. A. Kirschenbaum ◽  
E. T. Zawada
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Flow Rate ◽  
Sodium Excretion ◽  
Filtration Rate ◽  
Prostaglandin Synthesis ◽  
Urine Flow ◽  
Prostaglandin E ◽  
Excretion Rates

1. Three groups of anaesthetized dogs were studied to determine the role of renal prostaglandins in glucagon-induced natriuresis. 2. Urine flow, sodium and prostaglandin E excretion rates increased significantly in the experimental kidney with glucagon infusion (0.20 μg/min) into the renal artery. These changes were completely reversed after the administration of either of two inhibitors of prostaglandin synthesis. 3. Infusion of glucagon (0.20 μg/min) after the administration of either of the prostaglandin synthetase inhibitors failed to increase either urine flow rate or sodium excretion above control values and failed to elevate urine prostaglandin E excretion rates. 4. Infusion of glucagon (0.75–1.25 μg/min) resulted in significant elevations in urine flow rate, glomerular filtration rate, renal plasma flow, urine sodium and prostaglandin E excretion rates. 5. The data presented indicate that the diuresis and natriuresis seen with the infusion of glucagon (0.20 μg/min) are accompanied by an increase in urine prostaglandin E excretion and are reversed by the administration of inhibitors of prostaglandin synthesis, suggesting that the increased urine flow and sodium excretion rates are dependent on prostaglandin-mediated mechanisms. The administration of glucagon in higher doses appears to be associated with alterations in electrolyte excretion and glomerular filtration rate, which presumably is related to factors other than prostaglandin synthesis and release.

scholarly journals The Effect of Hydropenia and Oral Water Loading on Renal Lysozyme Handling and N-Acetyl-β-d-Glucosaminidase Excretion in Man

1986 ◽  
Vol 23 (4) ◽  
pp. 453-457 ◽  
Author(s):  
Mark T Houser
Keyword(s):  
Flow Rate ◽  
Renal Injury ◽  
Human Subjects ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Weak Correlation ◽  
Water Loading ◽  
Turbidimetric Method ◽  
Recovery Techniques ◽  
Normal Human

To substantiate the effects of urine flow rate on renal lysozyme handling and N-acetyl-β-d-glucosaminidase (NAG) excretion, experiments were performed in normal human subjects. Urine flow rate was varied by overnight fluid deprivation and progressive diuresis induced by oral water loading. Lysozyme measurements were made using an improved turbidimetric method and NAG determinations using a modified fluorometric assay utilising individual recovery techniques. Fractional lysozyme clearance and lysozyme excretion demonstrated a nearly linear relationship with urine flow rate ( r=0·78, r=0·80, P<0·0005), and both were elevated significantly in samples obtained during diuresis. NAG excretion, however, demonstrated a significant but weak correlation ( r=0·47, P<0·005) with fractional urine flow rate. A significant ( P<0·05) difference in NAG activity occurred only during the period of hydropenia, when a decrease in excretion was observed. These findings suggest that the effect of diuresis on lysozyme excretion should be considered in studies utilising this enyzyme as a marker of renal injury.

High urine flow rate increases prostaglandin E excretion in the conscious dog

1981 ◽  
Vol 22 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Lucius F. Wright ◽  
Steven G. Rosenblatt ◽  
Meyer D. Lifschitz
Keyword(s):  
Flow Rate ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Prostaglandin E ◽  
Conscious Dog

Lithium clearance in dogs: effects of water loading, amiloride and lithium dosage

1992 ◽  
Vol 82 (6) ◽  
pp. 635-640 ◽  
Author(s):  
Michael SHALMI ◽  
Jørn Bech Laursen ◽  
Jacob Plange-RHULE ◽  
Sten Christensen ◽  
John Atherton ◽  
...  
Keyword(s):  
Flow Rate ◽  
Arginine Vasopressin ◽  
Lithium Concentration ◽  
Lithium Carbonate ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Conscious Dogs ◽  
Acute Administration ◽  
Renal Handling ◽  
Water Loading

1. The influences of lithium dosage, urine flow rate and acute administration of amiloride on the renal handling of lithium in normal conscious dogs were investigated. 2. Lithium was administered in the diet at daily doses of 100 mg or 2 mg of lithium carbonate for the 2 days preceding the investigation. Urine flow rate was altered by water loading with and without arginine vasopressin infusion (5 pg min−1 kg−1). Amiloride was administered as an intravenous bolus (130 μg/kg) followed by a continuous infusion (1.22 μg h−1 kg−1). 3. Glomerular filtration rate (exogenous creatinine clearance) did not change within series and was not different between series; it averaged 3.27 ml min−1 kg−1. Control levels of fractional lithium excretion (12.4 ± 1.2%, mean ± sem) were not influenced by hydration, hydration plus arginine vasopressin administration or the lithium dosage. However, in hydrated dogs having a plasma lithium concentration of 130–140 μmol/l, amiloride administration was associated with a 5% increase in fractional lithium excretion (P 0.01). 4. It is concluded that distal tubular lithium reabsorption may take place in sodium-replete conscious dogs undergoing water diuresis. The low fractional lithium excretion even during amiloride infusion (14.1–16.8%) may well be due to a high fractional reabsorption of lithium in the proximal tubules; however, a significant reabsorption of lithium distal to the proximal straight tubules by amiloride-insensitive pathways cannot be excluded.

Patterns of Cortisol and Adrenaline Variation in Australian Aboriginal Communities of the Kimberley Region

1995 ◽  
Vol 27 (1) ◽  
pp. 107-116 ◽  
Author(s):  
Lincoln H. Schmitt ◽  
G. Ainsworth Harrison ◽  
Randolph M. Spargo ◽  
Tessa Pollard ◽  
Giles Ungpakorn
Keyword(s):  
Flow Rate ◽  
Aboriginal People ◽  
Excretion Rate ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Aboriginal Communities ◽  
North West ◽  
Australian Aboriginal ◽  
Cortisol Excretion ◽  
Excretion Rates

SummaryUrinary cortisol and adrenaline excretion rates were measured in three Australian Aboriginal communities in the Kimberley region in the north-west of the country. The three communities, Derby, Kalumburu and Kupungarri, differ in size and remoteness and some lifestyle parameters. Cortisol excretion rate is associated with age and urine flow rate, but there is no association with smoking or the consumption of alcohol. All three communities show very high cortisol excretion rates compared to a sample of UK (Oxford) residents and there are also differences between the three communities. Adrenaline excretion rate also shows associations with age and urine flow rate, but not with smoking. Aboriginal people in the Kimberley region excrete adrenaline at a slightly higher rate than that found in Oxford, which itself is high by world standards. There are no marked differences between communities in their adrenaline excretion rates. Alcohol drinkers in Derby, where alcohol is freely available, have higher adrenaline output than non-drinkers.

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