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PubMed2000

Kappa opioid-induced diuresis in female vs. male rats.

Kappa opioid agonists may produce dissimilar discriminative and analgesic effects in female vs. male subjects. The present study was conducted to determine whether a prototypic physiological effect of kappa agonists--diuresis--also differs between the sexes. When data were not corrected for individual differences in body weight, the kappa agonists U69,593 (0.03-3.0 mg/kg), U50,488 (0.3-10 mg/kg), (-)-bremazocine (0.001-0.1 mg/kg) and (-)-pentazocine (1-10 mg/kg), as well as a nonopioid diuretic, furosemide (1-10 mg/kg) produced significantly greater diuresis in normally hydrated, age-matched males than females; however, there was no sex difference in the diuretic effect of butorphanol (0.3-3.0 mg/kg), or in the antidiuretic effect of the mu agonist morphine (1.0-5.6 mg/kg, in water-loaded rats). In contrast, when data were corrected for individual difference in body weight, U69,593, U50,488, (-)-bremazocine, (-)-pentazocine, and furosemide produced nearly equivalent diuresis/kg in females and males, whereas butorphanol produced slightly greater diuresis/kg, and morphine produced significantly less antidiuresis/kg, in females than males. U69,593-induced diuresis was highly similar in males and females of similar body weight (i.e., different ages). U69,593 effects were dose-dependently antagonized by the kappa antagonist nor-binaltorphimine in both sexes, indicating a common, kappa receptor-mediated mechanism of action. (-)-Bremazocine was slightly more potent in suppressing vasopressin in 24-h water-deprived males than females. These results suggest that the greater diuretic effects of kappa receptor-selective opioid agonists in male rats are primarily due to males' larger body size (greater body water) relative to age-matched females, but may also be attributed to slightly greater vasopressin suppression in males.

Animals↗
PubMed2002

Initial results of the effects of diuresis on gadolinium enhancement in MR imaging of the abdomen.

RATIONALE AND OBJECTIVES: The authors performed this study to assess the effects of furosemide-induced diuresis on paramagnetic contrast material enhancement at magnetic resonance (MR) imaging of the kidney, liver, spleen, and psoas muscle. MATERIALS AND METHODS: Twenty-five patients (average age, 44.9 years; age range, 23-74 years; 13 men, 12 women) who were suspected of having unilateral renal hydronephrosis received 0.1 mmol/kg contrast material with a standardized injection and imaging protocol to assess organ signal intensity at 0-5 minutes after injection. All patients had a normal serum creatinine level. Imaging was performed with a 1.5-T magnet by using a fat-suppressed fast spoiled gradient-echo pulse sequence and a 70 degrees flip angle. Eight patients received 40 mg of furosemide 10 minutes before contrast material injection. RESULTS: The areas of the renal cortical and medullary signal intensity curves minus baseline in the unilateral normal kidneys were significantly greater in the group who received furosemide (P = .026 and P = .037, respectively). The areas of the renal cortical and medullary signal intensity minus baseline in the unilateral hydronephrotic kidneys were also significantly greater in the group that received furosemide (P = .036 and P = .026, respectively). There was a statistically significant increase in splenic enhancement (P = .02) and a tendency for increased liver (P = .09) and psoas muscle (P = .08) enhancement. CONCLUSION: Furosemide-induced diuresis appears to potentiate the cortical and medullary MR renogram, as well as the MR splenogram. A rapid shift in water compartmentalization from the intracellular to the extracellular space and increased renal water content with diuresis are possible explanations.

Abdomen↗
PubMed2003

Body water handling in response to hypertonic-saline induced diuresis in fasting northern elephant seal pups (Mirounga angustirostris).

During natural fasting conditions in postweaned northern elephant seal (NES) (Mirounga angustirostris) pups, urinary water loss is minimized and percent total body water (TBW) is maintained constant. However, following infusion of hypertonic saline, glomerular filtration rate (GFR) and urine output increased in fasting pups. Therefore, we quantified the magnitude of the hypernatremia-induced diuresis relative to the animal's total body water (TBW) pool and the percentage of filtered water reabsorbed. Following a 24 h control period, naturally fasting NES pups (n=7) were infused (4 ml min(-1)) with hypertonic saline (16.7%) at a dose of 3 mmol NaCl kg(-1) body mass. Total body water was estimated prior to infusion by tritium dilution, GFR was estimated by standard creatinine clearance, and urine output (V) was measured for 24 h during the control and post infusion periods. Percentage of filtered water reabsorbed was calculated as (1-(V/GFR))x100. Twenty-four hours following the infusion, GFR (control: 69+/-12 ml min(-1) and post-infusion: 118+/-19 ml min(-1); mean+/-S.E.) increased 77+/-28% above control and the percentage of filtered water reabsorbed was decreased 0.4+/-0.1%. The increase in urine output (control: 218+/-47 ml d(-1) and post-infusion: 883+/-92 ml d(-1)) accounted for 1.7+/-0.2% of the pups' TBW. The hypernatremia-induced diuresis was accompanied by the loss of body water indicating the lack of water retention. Although the 77% increase in GFR was only associated with a 0.4% decrease in the percentage of filtered water reabsorbed, this decrease was significant enough to result in a 4-fold increase in urine output. Despite the observed diuresis, fasting NES pups appear to possess an efficient water recycling mechanism requiring only a small percentage of body water to excrete an excess salt load. This water recycling mechanism may allow pups to avoid negative perturbations in body water as they initiate feeding in a marine environment following the fast.

Absorption↗
PubMed1984

Comparison of mesna with forced diuresis to prevent cyclophosphamide induced haemorrhagic cystitis in marrow transplantation: a prospective randomised study.

A prospective randomised study was carried out to compare the effect of mesna (2-mercaptoethane sulphonate sodium) with that of forced diuresis in preventing cyclophosphamide induced haemorrhagic cystitis in marrow transplant recipients. Sixty-one consecutive BMT recipients were randomised for treatment with forced diuresis or mesna. The incidence of macroscopic haematuria was significantly lower in the mesna treated group (chi 2 = 4.03, P less than 0.05). No specific side effects of mesna were detected. The lymphopenia induced by cyclophosphamide in the aplastic recipients was similar in the mesna and forced diuresis groups suggesting that mesna has no effect on the lymphocytotoxic activity of cyclophosphamide, although 6 out of 7 episodes of graft failure documented in the study occurred in mesna treated patients. As a result of this study our present policy is to use mesna in all BMT recipients but to continue careful documentation of the incidence of graft failure.

Adolescent↗
PubMed1994

Osmotic diuresis before Homer W. Smith: a winding path to renal physiology.

It was towards the end of the 18th century that a curiosity arose about what controlled the flow of urine. It was noted that though a patient's kidneys might be destroyed, the flow of urine continued until death. This puzzling phenomenon might have been understood had Ségalas's and Wöhler's observations been properly appreciated, that an extra load of urea, or any other substance that is excreted by the kidney, causes a diuresis. Nevertheless, these experiments were forgotten, and because of Bowman's and Ludwig's studies fluctuations in urine flow were ascribed to changes in blood pressure. It was not until 1870 to 1880 that Ustimowitsch, Falck and Richet stressed the role of urinary solutes on urine flow. Around 1900, Cushny also studied the diuretic effect of different solutes excreted in the urine and actually described what is now called an osmotic diuresis, though he did not use the term. These studies enabled him to deliver his "modern view" of the Secretion of the Urine. This was the first coherent concept which attempted to explain the formation of the urine and the regulation of its composition according to a pressure of a selective tubular reabsorption controlled by the needs of the "Milieu Intérieur." When glomerular and tubular functions became quantifiable, Homer W. Smith's disciples were able to define the exact nature of an osmotic diuresis and that explained the paradox of polyuria and renal failure.

Animals↗
PubMed1999

Eukaliuric diuresis and natriuresis in response to the KATP channel blocker U37883A: micropuncture studies on the tubular site of action.

1. Systemic application of U37883A, a blocker of ATP sensitive potassium (KATP) channels, elicits diuresis and natriuresis without significantly altering urinary potassium excretion. 2. To elucidate tubular sites of action upstream to the distal nephron, micropuncture experiments were performed in nephrons with superficial glomeruli of anaesthetized Munich-Wistar-Frömter rats during systemic application of U37883A (1, 5 or 15 mg kg-1 i.v.). 3. The observed eukaliuric diuresis and natriuresis in response to U37883A at 15 mg kg-1 was accompanied by an increase in early distal tubular flow rate (VED) from 10 - 18 nl min(-1) reflecting a reduction in fractional reabsorption of fluid up to this site (FR-fluid) of 13%. The latter proposed an effect on water-permeable segments such as the proximal tubule which could fully account for the observed reduction in fractional reabsorption of Na+ up to the early distal tubule (FR-Na+) of 8% and the increase in early distal tubular Na+ concentration ([Na+]ED) from 35 - 51 mM whereas [K+]ED was left unaltered. 4. In comparison, furosemide (3 mg kg-1 i.v.), which acts in the water-impermeable thick ascending limb, elicited diuresis, natriuresis and kaliuresis which were associated with a fall in FR-Na+ of 10% with no change in FR-fluid, and a rise in [Na+]ED from 42 - 117 mM and [K+]ED from 1.2 - 5.7 mM with no change in VED. 5. Direct late proximal tubular fluid collections confirmed a significant inhibition of fluid reabsorption in proximal convoluted tubule in response to systemic application of U37883A. 6. These findings suggest that the diuretic and natriuretic effect upstream to the distal tubule in response to systemic application of U37883A involves actions on water-permeable segments such as the proximal convoluted tubule.

Adamantane↗
PubMed2006

Evaluation of intra-renal oxygenation during water diuresis: a time-resolved study using BOLD MRI.

Hypoxia of the renal medulla is a possible precursor to the onset of acute renal failure in humans and therefore an understanding of the factors influencing the oxygenation status within the renal medulla is very important. Blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) has been shown to non-invasively evaluate intra-renal oxygenation levels of the renal medulla in humans. A newly implemented three-dimensional (3-D) multiple gradient-recalled echo sequence, which permits examination of temporal responses to physiological or pharmacological stimuli, was used to monitor changes in intra-renal oxygenation status during water diuresis. Five healthy, young subjects (22+/-1.2 years) took part in the study. BOLD MRI data were acquired before and after water loading. Studies were repeated on a separate day after the subjects were pretreated with naproxen. Water diuresis significantly improved renal medullary oxygenation levels in all subjects (pre-waterload=30.3 1/s vs post-waterload 22.8 1/s); however, the temporal response was found to be subject dependent. In the presence of cyclooxygenase (COX) inhibition by naproxen, the improvement in oxygenation during water diuresis was completely abolished (pre-waterload=27.5 1/s vs post-waterload 28.5 1/s). Monitoring of temporal responses for the first time during water loading allowed for an appreciation of subject dependence. Comparison of the temporal response in terms of slopes demonstrated a significant difference between the waterload studies with and without naproxen (with naproxen=0.056 1/(s min) vs without naproxen=0.25 1/(s min)). The observed effects of naproxen were consistent with previous findings with COX inhibition.

Adult↗
PubMed1984

Effect of acetylsalicylic acid and of indomethacin on diuresis in man: the role of cyclo-oxygenase inhibition.

The effect of acetylsalicylic acid (ASA, 3 g/day for 3 days) and of indomethacin (IND, 150 mg/day for 3 days) on diuresis and on the excretion of prostaglandin E2 (PGE2) was studied in six healthy, male volunteers. After overnight deprivation the subjects received an oral water load (20 ml/kg) and hourly urine volumes were replaced by an equivalent volume of water by mouth for 4 h. Pretreatment with both ASA and IND induced a comparable suppression (P less than 0.05 to less than 0.001) in the excretion of PGE2, but only IND also reduced (P less than 0.05) diuresis, free water clearance and the excretion of sodium. The excretion of creatinine was uninfluenced by both ASA and IND. These data indicate that a mechanism other than cyclo-oxygenase inhibition is involved in the effect of IND and ASA on diuresis in man.

Adult↗
PubMed1990

Active and inactive urinary kallikrein in man: effects of diuresis and antidiuresis.

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.

Adult↗
PubMed1998

The role of antidiuretic hormone in cold-induced diuresis in the anaesthetized rat.

The aim of this study was to investigate whether the increased diuresis in consequence of hypothermia is due to a depression of the hypothalamic release of antidiuretic hormone (ADH). The plasma concentration of antidiuretic hormone and the effect of intravenous (i.v.) administration of 65 ng kg-1 desmopressin (selective V2-receptor agonist) were determined in the anaesthetized rat. In spite of a 50% (P < 0.001) decrease in glomerular filtration rate, urine flow increased sixfold (P < 0.01) and urine sodium excretion increased sevenfold (P < 0.05), whereas urine osmolality decreased (P < 0.001). At the same time plasma antidiuretic hormone decreased from 7.5 +/- 1.1 to 3.8 +/- 0.4 pg mL-1 (P = 0.01). After injection of desmopressin urine flow was completely restored, whereas urine osmolality and sodium excretion were only partially normalized. Since tubular conservation of water and fractional water reabsorption decreased during hypothermia, the diuresis must have resulted from an augmented loss of water. This is further supported by the fact that osmolal excretion was not influenced either by hypothermia or by desmopressin. It is concluded that the diuresis in consequence to hypothermia is due both to a decrease in the release of ADH and to a reduction of renal medullary hypertonicity.

Anesthesia↗
PubMed2001

Usefulness of forced diuresis for acute boric acid poisoning in an adult.

BACKGROUND: Boric acid is generally not recognized as a poisonous substance. However, boric acid has potentially fatal actions such as hypotension, metabolic acidosis and oliguria. Death may result from circulation collapse and shock. OBJECTIVE: We present a clinical case history of the successful use of forced diuresis with furosemide and intravenous fluid for boric acid poisoning. SUBJECT: A 26-year-old female who attempted suicide by consuming a large quantity of boric acid. She was brought to the hospital in a state of clouded consciousness, fever and erythema 14 h after ingestion. METHOD: 3.25 L of intravenous fluid and 100 mg of furosemide were administered over a period of 4 h in the intensive care unit and the serum and urinary concentrations of boric acid measured. RESULTS: The elimination rate of boric acid obtained with diuresis was similar to that obtained with haemodialysis on a previous occasion when the same patient attempted suicide with boric acid. The patient showed only temporary emesis and diarrhoea along with erythema, and was moved to the general ward 4 h after admission. Although in the general ward the patient's fever persisted and nausea, vomiting and headache often recurred, possibly because of an insufficient dose of furosemide, the patient's condition steadily improved over the 64 h after admission. CONCLUSION: Forced diuresis without haemodialysis is recommended early after admission for boric acid poisoning.

Adult↗
PubMed1977

Intoxication with primidone: continuous monitoring of serum primidone and its metabolites during forced diuresis.

An 18 year old girl is reported, who ingested 15 g of primidone (Liskantin), 330 mg/kg, to commit suicide. Continuous monitoring of the serum levels of primidone, PEMA, and phenobarbital revealed increased elimination of primidone by forced diuresis (6000 ml/24 hours). It is concluded that forced diuresis inhibits the otherwise mandatory increase in primidone metabolites, PEMA and phenobarbital. It is suggested that even after improvement of the clinical symptoms forced diuresis should be continued for at least 48 hours. In epileptic patients the reinstitution of primidone therapy should be considered only on the third day after accidental ingestion, if the clinical symptoms have improved, and if there is no possibility of immediate determination of primidone serum levels.

Adolescent↗
PubMed1995

Diuresis renography in the diagnosis and follow-up of nonobstructive primary megaureter.

Due to the widespread use of obstetrical ultrasonography with concomitant fetal screening, congenital uropathies are usually diagnosed in asymptomatic neonates. The main issue is to distinguish those cases of dilatation which are clearly obstructive and need surgical treatment from those which are within the normal anatomical range. Out of 47 patients with primary megaureter, 23 were nonobstructive and these are the subject of our study. There were 16 males and 7 females. Thirteen were located on the left side, 7 on the right side and 3 were bilateral, adding up to 26 renoureteral units. Prenatal diagnosis was made in 16 cases, the oldest patient diagnosed was 9 years old. All infants were evaluated with ultrasonography, voiding cystourethrography, excretory urography and diuresis renography. The latter has been the most important test inducing us to adopt a conservative attitude. Differential renal function was more than 40% in 24 units and in 2 it was more than 35%. Diuretic renograms were type IIIa (dilated, nonobstructed) in 19 cases and IIIb (dilated, partially obstructed) in 7. There were 2 cases with vesicoureteral reflux in the contralateral system. We performed ultrasonography and diuresis renography during the follow-up. There were 8 cases with type I (normal) renograms and 17 cases with type IIIa. Only one patient developed an obstruction and was operated on. Differential renal function did not deteriorate in any of the cases. Urography was performed in 9 cases during the follow-up. All the patients have remained asymptomatic during the surveillance, except for 2 cases which presented urinary tract infection. BUN, creatinine and other biochemical figures remained within the normal range. The follow-up period of time ranged between 1 and 8 years. We conclude that primary megaureter must be assessed and followed up and that the main test to be used is diuresis renography.

Child↗
PubMed1986

Radiochromium distribution during saline diuresis.

Free water diuresis in vasopressin-deficient Brattleboro rats does not influence body conservation of chromium (Cr+3), suggesting a proximal tubular site for renal Cr reabsorption. Other data suggest that Cr conservation is accomplished primarily by lack of glomerular filtration or by tissue binding to a specific Cr-binding substance. To provide further data, radiochromium (51Cr) retention and tissue distribution were studied in SHR and WKY rats undergoing saline diuresis. Despite high urine flows, body retention and urinary excretion of 51Cr were unchanged. Tissue content of 51Cr was minimally and not consistently influenced by saline diuresis in either rat strain. Compared to WKY rats, the SHR rats had a trend to lower serum and tissue 51Cr content but higher tissue/serum 51Cr ratios. These data fail to incriminate collecting duct reabsorption in Cr conservation but are compatible with proximal Cr reabsorption or either of the two hypotheses mentioned above. The decreased serum 51Cr content of SHR rats may be due to the mechanical effect of increased plasma and extracellular volumes. One possible explanation for the increased tissue/serum 51Cr ratios may be the presence of a factor in SHR rats promoting cellular Cr transport. However, there is no present evidence to suggest that any of the hormones believed capable of increasing Cr transport (insulin, growth hormone, thyroxine, ADH) are increased in the SHR rat.

Animals↗
PubMed1990

Inhibition of the metabolism of atrial natriuretic factor causes diuresis and natriuresis in chronic heart failure.

Atrial natriuretic factor (ANF) is a peptide hormone secreted by the heart that is degraded in vivo by endopeptidase 24:11 (atriopeptidase). UK 69,578 is a novel atriopeptidase inhibitor that raises plasma levels of ANF in animals and normal volunteers, with associated diuresis and natriuresis. This study examines the effects of UK 69,578 in patients with mild heart failure. UK 69,578 was administered as an intravenous infusion over 20 min in a placebo-controlled, cross-over study to six patients with stable (NYHA Class 2) chronic heart failure. The atriopeptidase inhibitor was well tolerated and no side effects were encountered. Mean baseline plasma ANF was elevated at 88 pg/mL (normal less than 50), and increased 2- to 5-fold after UK 69,578 administration. Plasma ANF did not change significantly following placebo. There was a marked diuresis after UK 69,578 compared to placebo. Urinary sodium excretion doubled for 4 to 6 h, but there was no significant rise in potassium excretion. There was no increase in plasma active renin concentration during the study period. Noninvasive hemodynamic monitoring revealed no significant changes in heart rate, systemic arterial blood pressure, or echocardiographic left ventricular dimensions. However, invasive measurements using a Swan-Ganz catheter demonstrated falls in mean right atrial and pulmonary artery wedge pressures after UK 69,578. There was no change in cardiac output. Thus, inhibition of endopeptidase 24:11 by UK 69,578 results in significant elevation of plasma ANF, with associated diuresis, natriuresis and venodilatation. The compound was well tolerated in these patients with mild chronic heart failure.

Adult↗
PubMed1976

Significance of diuresis-provoked bacteriuria.

Of 52 clinically healthy, ambulant elderly subjects with urine that was sterile or contained less than 0.2 X 10(5) bacteria/ml before diureisi, 11 (21.2%) responded to oral water loading and intravenous treatment with furosemide with a bacterial excretion rate of greater than 2.4 X 10(5)/min. Subjects with bacteriuria had decreased blood pressure, rate of creatinine clearance, maximal level of urinary creatinine, and maximal urinary flow. Twenty-nine of the nonbacteriuric and eight of the subjects who developed bacteriuria after diuresis were retested one to two years later. No subject had received antibacterial agents in the interim. The infections of four of the original subjects who had developed bacteriuria had cleared up and showed functional improvement. The remaining four subjects who had developed bacteriuria during the first study and three subjects who had been nonbacteriuric during the first study had concentrations of bacteria ranging from 0.05 X 10(5) to 1.80 X 10(5)/ml before diuresis in the second study, and excreted increasing numbers of bacteria (from 0.12 X 10(5) to 9.0 X 10(5)/min) in response to the diuretic loading. Two of the subjects who were bacteriuric in both surveys were infected with different bacteria during the two studies. The data show the high frequency of occult bacteriuria in ostensibly healthy elderly patients that is revealed only by forced diuresis, the detectable functional deficits, the improvement after clearing of the infections, and the rapid turnover between infected and clear periods.

Aged↗
PubMed2006

Polynocturia in chronic kidney disease is related to natriuresis rather than to water diuresis.

BACKGROUND: Nocturnal polyuria has been well known in renal insufficiency. Recently, we found that as renal function deteriorated in chronic kidney disease (CKD), natriuresis was enhanced during the night with nocturnal blood pressure elevation. In the present study, we investigated whether nocturnal polyuria in CKD was due to the inability to concentrate urine, as previously proposed, or based on osmotic diuresis mainly by natriuresis. METHODS: In 27 CKD patients, circadian rhythms of urinary sodium, potassium, urea and osmolar excretion rates (U(Na)V, U(K)V, U(urea)V, U(osm)V) as well as of urinary volume (V) and free-water clearance (C(H(2)O)) were estimated during both daytime (6:00 to 21:00) and nighttime (21:00 to 6:00). Then, the night/day ratios of these parameters were analysed in relation to creatinine clearance (C(cr)) as a marker of glomerular filtration rate. RESULTS: C(cr) had significantly negative relationships with night/day ratios of V (R = -0.69; P < 0.0001), U(osm)V (R = -0.54; P = 0.004) and U(Na)V (R = -0.63; P = 0.0005), but no correlation with night/day ratios of C(H(2)O) (R = -0.33; P = 0.1), U(K)V (R = -0.29; P = 0.1) or U(urea)V (R = -0.31; P = 0.1). Linear and multiple regression analysis identified nocturnal natriuresis rather than urea excretion as an independent determinant of nocturia. CONCLUSION: As renal function deteriorated, nocturnal polyuria was seen, being consistent with classical recognition. Furthermore, this increase in nocturnal urine volume seemed related to osmotic diuresis mainly by natriuresis rather than to water diuresis or urea excretion.

Blood Pressure↗
PubMed1997

Value of diuresis renography in the post-natal period of assumed physiological renal immaturity.

The aim of this study was to determine if it is possible to exclude renal obstruction using diuresis renography in the first 6 weeks of life (the period of physiological renal immaturity), thus avoiding unnecessary invasive procedures, such as the Whitaker test or surgery. Diuresis renography with 123I-hippuran was performed in 27 patients aged less than 6 weeks and in 50 older children who acted as a reference group (age 6 weeks to 1 year, n = 28; age 1-10 years, n = 22). All 27 patients had significant dilatation of the pelvicalyceal system on ultrasonography. Renal curves were evaluated by mathematical curve characteristics (split renal function, counts, T-max, etc.) as the visual grade of obstruction. Whole-kidney regions of interest were defined on images summed over 30 min; renal parenchyma on images summed over 5 min. The renal curves of 18/27 patients indicated tracer accumulation and led to frusemide administration. Only two patients showed no significant response to frusemide and had to be further investigated by the Whitaker test. The frequency of kidneys with no response to frusemide revealed no significant differences in the three groups. Whole-kidney evaluation resulted in an overestimation of obstruction in 9/150 kidneys, which matches the lower correlation to the DMSA separation values for this method of evaluation. In contrast with the literature, significant post-renal obstruction can be excluded by diuresis renography in most cases in spite of renal immaturity and can help to avoid invasive procedures.

Child↗