Comparison of Inulin, Iothalamate, and 99mTc-DTPA for Measurement of Glomerular Filtration Rate (original) (raw)
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Clinical science, 1968
The standard method of estimating the rate of glomerular filtration (G.F.R.) in man has been by the renal clearance of inulin since it was demonstrated. that this plant polysaccharide is neither secreted nor reabsorbed by the renal tubules. The criteria which must be satisfied by a substance for its renal clearance to cive a valid measure of glomerular filtration rate have been discussed in detail by Smith (1951). Chemical methods for the determination of inulin in plasma and urine have been rather unsatisfactory (Smith 1951) and a variety of substances have been studied in an attempt to find a substitute for inulin. The endogenous creatinine clearance is widely used for clinical purposes but the creatinine/inulin clearance ratio exceeds unity in many human subjects indicating a variable deree of tubular secretion of creatinine (Smith 1 951 , Berlune et al 1 964) and this clearance is not a reliable measure of glomerular filtration in man. Recently a number of compounds labelled with radioisótopes have been studied and found to have clearances similar to'that of inulin. Al.lyl inulin labelled with 1251 has a clearance virtually identical to that of inulin in tae dog (Concannon et al 1961 +) but is not rea¡._.ly
Clinica Chimica Acta, 2012
Among issues susceptible to hamper a reliable measurement of inulin clearance, those regarding the dosage of inulin are largely neglected. We have compared the analytical performances of 2 commonly used methods of inulin dosage (one "acid" and one "enzymatic" method) and studied their potential impact on the glomerular filtration rate (GFR) value given by inulin clearance. Repeatability, uncertainty and the beta-expectation limits were evaluated from predetermined serum and urine pools of inulin. Agreement between the two methods was analyzed from 99 inulin clearances performed in renal transplant patients. Impact of the method of dosage on GFR evaluation was simulated according to the respective beta-expectations limits of each method. Overall, intra-assay coefficient of variability and relative bias were inferior to 5% and 10% for both methods. Contrary to the acid method, analytical performance of the enzymatic method was not influenced by the presence of glucose. The relative difference in GFR values obtained with the two methods in transplant patients was − 0.4 ± 10%. Simulations suggested that changes in inulin concentration attributable to analytical error could modify the value of GFR from − 12% to + 28%. In conclusion, while analytical performances are globally acceptable for both methods, they are not strictly equivalent. The impact on the determination of GFR, albeit limited, is not negligible and adds to other sources of inaccuracy. International standardization for the dosage of inulin is necessary.
Kidney International, 2002
opaque dye in x-ray imaging of the kidney excretory system (intravenous urography, IVU); moreover, for many years it has been used to estimate GFR when it is radio-Key words: mannitol, remnant kidney, measurement of fluid reabsorplabeled with 125 I [2]. However, the potential for significant tion, Jv, single nephron GFR, free flow micropuncture, estimating glomerular filtration rate. radioactive exposure is considerable, so in the early 1990s non-radiolabeled iothalamate measured by high-pres
Clinica Chimica Acta, 1970
I. Measurements of glomerular filtration rate (GFR) using inulin, %rEDTA, and a phosphate infusion technique were compared in order to assess their relative accuracy. 2. GFR was determined from phosphate data in a series of 66 infusions in 50 subjects. Comparison with simultaneous inulin clearance (180 measurements during 38 infusions) gave a ratio of GFR derived from phosphate data (GFR,)/mean inulin clearance of 1.00 & 0.03 (S.E.). Comparison with simultaneous 51CrEDTA clearance (189 measurements in 33 infusions) gave a ratio of %rEDTA clearance/GFR, of 0.94 & 0.03 (S.E.). 3. Separate direct comparison of renal inulin clearance with 51CrEDTA clearance in another series of 65 measurements from 15 infusions gave a ratio of %rEDTA clearance/inulin clearance of 0.96 Jr 0.02 (S.E.). 4. The method of determining GFR without urine collection was also used to compare inulin with WrEDTA. In 13 infusions this urineless GFR ratio of 51CrEDTA/ inulin was 0.92 & 0.04 (S.E.). The urineless GFR gave significantly higher absolute values than mean standard clearances, in the ratio of 1.07 for both inulin and 51CrEDTA; the discrepancy was probably due to incomplete equilibration resulting from purposely shortened infusion times. 5. It was concluded that an infusion technique based on the measurement of phosphate alone gives an accurate measure of GFR, that GFR is consistently underestimated by the use of 51CrEDTA, and that the method without urine collection overestimates renal clearance when infusion times are shorter than 4 h.
2003
The purpose of this study was to evaluate the validity of the single injection of inulin (PCIn) compared with standard exogenous creatinine clearance (CCr) in dogs with renal artery stenosis. Two methods for evaluating glomerular filtration rate (GFR), after single bolus intravenous administration of inulin, were assessed in 15 dogs with renal artery stenosis to reduce blood flow ranging from 30% to 80%. The first method was calculated by determination of plasma clearance of inulin using the quotient of the administered dose of inulin (1 g) divided by the area under the plasma inulin concentration vs. time curve (PCIn1) while the second method was calculated using a two-compartment model (PCIn2). The relationship between CCr and the plasma concentration of inulin 75 minutes (C75) after single bolus intravenous administration of inulin was also determined. Results indicated a significant correlation between either of PCIn1, PCIn2 or C75 with conventional CCr. These results support th...
Comparison of renal extraction efficiencies for radioactive agents in the normal dog
Journal of Nuclear …, 1981
tection of renal disease or for evaluation of renal func tion,it iscustomaryto measure andcomparetheirrel ative blood and plasma clearances, urinary excretion, and organ distribution at various time intervals after intra venous injection. Renal clearance is also calculated under steady-state conditions from the total quantity excreted in the urine in a given time, divided by the average plasma level. Renal clearance, however, is not applicable to substances that are stored, synthesized, or metabolized by the kidney (1 ). This would include several radioactive agents that accumulate in the renal parenchyma.
American Journal of Veterinary Research, 2020
OBJECTIVE To establish a reference interval for glomerular filtration rate (GFR) determined by measuring serum clearance of a single IV dose of inulin in clinically normal cheetahs (Acinonyx jubatus) and compare serum symmetric dimethylarginine (SDMA) concentration in cheetahs with GFR. ANIMALS 33 cheetahs housed at 3 institutions. PROCEDURES A single bolus of inulin (3,000 mg/m2) was administered IV, and 5 serial blood samples were collected and analyzed for serum inulin concentration with the anthrone technique. The GFR was estimated with a modified slope-intercept method for the slow component of the serum concentration-versus-time curve. Blood urea nitrogen and serum creatinine concentrations were measured in samples obtained immediately prior to inulin administration, and serum SDMA concentration was measured in stored samples. RESULTS Mean ± SD measured GFR was 1.58 ± 0.39 mL/min/kg, and the calculated reference interval was 0.84 to 2.37 mL/min/kg. There were significant negat...
European Journal of Nuclear Medicine, 1991
Simultaneous measurements of the clearance rates of technetium 99m diethylenetriaminepentaacetie acid (99mTc-DTPA) and chronium 51 ethylenediaminetetraaeetic acid (SICr-EDTA) were performed in 30 patients with a range of renal function (glomerular filtration rates between 9 and 120 ml/min). Using multiple blood samples, the two clearance values correlated well (r=0.991, standard error 3.9 ml/min), but DTPA clearance was systematically higher by 7.6%. For each radiopharmaceutical, an equation was derived to correct clearance values obtained using only plasma samples taken at 2 and 4 h for the systematic error inherent in this technique compared with analysis of the complete plasma concentration-time curve. The root mean square error remaining after application of these equations was 1.9 ml/min for both the EDTA and DTPA data. The corresponding errors obtained using the equation derived by Brochner-Mortensen for EDTA plasma clearance were 2.2 ml/min and 1.9 ml/min, respectively, these values were not significantly different from those obtained using the equations derived in this study. Key words: Glomerular filtration rate -Technetium 99m diethylenetriaminepentaacetic acid -Chromium 51 ethylenediaminetetraaeetic acid Eur J Nucl Med (1991) 18:391-395
Rapid microtiter plate assay for determination of inulin in human plasma and dialysate
Journal of Pharmaceutical and Biomedical Analysis, 2002
A rapid, sensitive, and reproducible microtiter plate assay for the determination of inulin in human plasma, dialysate, and phosphate-buffered saline (PBS) was developed. Plasma or PBS samples (100 ml aliquots) were prepared by the addition of indole-3-acetic acid (150 ml) and HCl (3 ml) and then briefly vortex-mixed. Samples were then incubated in a 60°C water bath for 20 min, cooled in a room temperature water bath for 40 min, then diluted with deionized, distilled water (DDW; 3 ml) and again vortex-mixed. Finally, an aliquot (200 ml) of each sample was transferred to a 96-well microtiter plate and read spectrophotometrically at 490 nm. Dialysate samples were processed in a similar manner, but required an initial enzymatic step in order to remove dextrose and minimize assay interference. Samples (100 ml aliquots) were prepared by the addition of glucose oxidase/catalase solution (100 ml), briefly vortex mixed, and then incubated in a 37°C water bath for 60 min, samples were then reacted with indole-3-acetic acid as before. Calibration curves were linear over the concentration range of 0.5-4 mg/ml or 0.025-0.4 mg/ml for plasma or PBS and dialysate, respectively; correlation coefficients (r 2 ) were \ 0.99. The intraand inter-day coefficients of variation in plasma, PBS, and dialysate were B15%. This method is well suited for the rapid analysis of large numbers of samples and is currently being used for in vitro investigations of solute removal by hemodialysis.