Intraspecies allometry: correlation between kidney weight and glomerular filtration rate vs. body weight

1982 ◽  
Vol 242 (3) ◽  
pp. R303-R305 ◽  
Author(s):  
H. Hackbarth ◽  
D. Buttner ◽  
K. Gartner

Allometric equations of the form of Y = a*BWb were calculated between body weight (BW) on the one hand and either kidney weight (KW) or glomerular filtration rate (GFR) on the other. By using strain and sex means obtained from 24 different inbred strains of adult mice or F1-hybrids environmental and genetical influences could be separated statistically. Thus, allometric equations reported in this study describe exclusively genetic influence. The parameters for intraspecies allometric equations obtained in these studies were compared to those in the literature presenting interspecies relationships. The double logarithmic regressions of KW vs. BW gave results different from the interspecies equation. The difference between intra- and interspecies results of allometric relationships may be due to the experimental exclusion of environmental influences. The regression parameters for GFR vs. BW obtained for the inbred strains, however, agreed very well with those of the empirical equation for interspecies relationship and also with the theoretically expected value. The dependence of GFR on BW was found to be GFR = 0.036*BW0.74 +/- 0.15, where GFR is measured in ml/min and BW in g. The exponent of 0.74 seems to be a valid biological constant that is genetically determined within and across species lines.

1999 ◽  
Vol 67 (7) ◽  
pp. S156 ◽  
Author(s):  
C. B. Hughes ◽  
E. J. Bergstralh ◽  
T. S. Larson ◽  
M. D. Stegall ◽  
J. A. Velosa

1991 ◽  
Vol 81 (2) ◽  
pp. 271-279 ◽  
Author(s):  
P. G. McNally ◽  
F. Baker ◽  
N. Mistry ◽  
J. Walls ◽  
J. Feehally

1. Nifedipine ameliorates cyclosporin A-induced renal impairment in surgically intact (two-kidney) rats. This study investigates the effect of nifedipine on cyclosporin A nephrotoxicity in spontaneously hypertensive rats after either uninephrectomy or uninephrectomy with contralateral renal denervation. 2. Fourteen days after uninephrectomy pair-fed rats were injected for 14 days with cyclosporin A (25 mg/kg body weight) via the subcutaneous route and with nifedipine (0.1 mg/kg body weight) via the intraperitoneal route. Renal and systemic haemodynamics were measured in conscious unrestrained rats. 3. Whole-blood levels of cyclosporin A did not differ between groups (overall 352 ± 22 ng/ml, means ± sem). After uninephrectomy, cyclosporin A decreased the glomerular filtration rate (olive oil versus cyclosporin A: 0.96 ± 0.04 versus 0.70 ± 0.06 ml min−1 100 g body weight, P < 0.02) and effective renal plasma flow (1.94 ± 0.10 versus 1.38 ± 0.13, P < 0.01), and increased renal vascular resistance {(20.2 ± 1.8) × 104 versus (31.6 ± 3.3) × 104 kPa l−1 s [(20.2 ± 1.8) × 103 versus (31.6 ± 3.3) × 103 dyn s cm−5], P < 0.02} and mean arterial pressure (146.7 ± 6.7 versus 167.3 ± 2.9 mmHg, P < 0.05). Neither renal denervation nor nifedipine prevented the reduction in glomerular filtration rate or effective renal plasma flow induced by cyclosporin A. 4. This study infers that the sympathetic nervous system does not play an active role in cyclosporin A nephrotoxicity and demonstrates that the concomitant administration of nifedipine to rats with reduced renal mass does not ameliorate cyclosporin A-induced renal impairment.


1997 ◽  
Vol 92 (4) ◽  
pp. 397-407 ◽  
Author(s):  
JAN Carstens ◽  
Kaare T. Jensen ◽  
Erling B. Pedersen

1. The renal efficacy of urodilatin in humans has only been partly investigated. It is unknown whether intravenously infused urodilatin has an effect on sodium reabsorption in both the proximal and distal part of the nephron. 2. Twelve healthy subjects participated in this double-blind, placebo-controlled study in a crossover design. They received, in a randomized order, a short term (60 min) infusion of urodilatin in three different doses (10, 20 and 40 ng min−1 kg−1 of body weight) and placebo. Renal haemodynamics were estimated by clearance technique with radioactive tracers, and proximal tubular handling of sodium was evaluated by lithium clearance. 3. The 20 ng min−1 kg−1 dose increased the urinary sodium excretion and urinary flow rate compared with the effects of placebo. It increased the glomerular filtration rate and decreased the effective renal plasma flow. In addition, the dose increased the lithium clearance compared with placebo, but did not significantly change the fractional excretion of lithium. On the other hand, it markedly decreased the distal fractional reabsorption of sodium. It also had a suppressive effect on renin secretion. The systemic arterial blood pressure was unchanged, but the dose increased the pulse rate and the haematocrit. The highest dose (40 ng min−1 kg−1) induced a wide variation in the natriuretic and diuretic responses, probably due to a blood-pressure-lowering effect. 4. We conclude, that the urodilatin dose of 20 ng min−1 kg−1 of body weight was most efficacious in this short-term infusion study, and that it had potent natriuretic and diuretic qualities, probably due to stimulation of the glomerular filtration rate and inhibition of sodium reabsorption in the distal part of the nephron.


1981 ◽  
Vol 15 (2) ◽  
pp. 125-128 ◽  
Author(s):  
H. Hackbarth ◽  
E. Baunack ◽  
M. Winn

Bodyweight, kidney weight and glomerular filtration rate showed significant differences between strains-70% of the total variance was ascribed to the between-strain variance component-while the renal plasma flow showed only a slight strain difference due to a high within-strain variance component (63%). Heritability in the broad sense was 0·78 for bodyweight, 0·85 for kidney weight, 0·66 for glomerular filtration rate and 0·35 for renal plasma flow. There were significant genetic correlations between bodyweight and kidney weight (0·90), bodyweight and glomerular filtration rate (0·73), and between glomerular filtration rate and renal plasma flow (0·71), but not between kidney weight and kidney functions. Significant environmental correlations could be calculated only between bodyweight and all other variables, so that for comparison between strains it seems better to correct renal functions for bodyweight than for kidney weight, which would increase the variation of glomerular filtration rate.


1999 ◽  
Vol 67 (7) ◽  
pp. S91
Author(s):  
J. H. H. Nguyen ◽  
E. J. Bergstralh ◽  
J. M. Gloor ◽  
T. K. Neuharth ◽  
S. Sterioff ◽  
...  

1989 ◽  
Vol 30 (4) ◽  
pp. 383-389 ◽  
Author(s):  
A. Nygren ◽  
H. R. Ulfendahl ◽  
A. Fasching

The effects of a slow intravenous injection of contrast media (CM) on renal function and haemodynamics were investigated in euvolaemic and dehydrated rats. Iodine-equivalent doses (1600 mg I/kg body weight) of ioxithalamate, ioxaglate, iopamidol and iohexol were used. Glomerular filtration rate (GFR) and renal plasma flow (RPF) were assessed with clearance techniques. In euvolaemic rats no statistically significant decrease in GFR or RPF was found after CM injections. In the dehydrated rats the changes in GFR were more pronounced and this was significantly decreased in the ioxithalamate and iopamidol groups while RPF was still not decreased. This study indicates that dehydration potentiates adverse effects of CM on GFR and that there may be differences between the effects of low-osmolar and high-osmolar CM on GFR and also between different low-osmolar CM.


1997 ◽  
Vol 92 (6) ◽  
pp. 579-585 ◽  
Author(s):  
Herbert J. Kramer ◽  
Kriemhild Schwarting ◽  
Angela Backer ◽  
Harald Meyer-Lehnert

1. Obstructive jaundice predisposes the kidney to acute renal failure. Endothelin (ET), a potent renal vasoconstrictor and modulator of the tubular action of arginine vasopressin, has been suggested to play a pathogenetic role in acute renal failure. In the present study we therefore investigated renal function and the renal ET system in rats on day 4 after bile-duct ligation (BDL) or sham-operation (SO), without (n = 7 in each group) and with treatment with bosentan, a combined ETA/ETB receptor blocker, (n = 5 in each group). 2. On day 4 after BDL, serum bilirubin had increased to 226 ± 10 μmol/l (SEM) as compared with 6 ± 2 μmol/l in SO rats. Endogenous creatinine clearance, an index of glomerular filtration rate, was significantly reduced to 0.7 ± 0.1 ml min−1 g−1 of kidney weight after BDL as compared with 1.1 ± 0.1 ml min−1 g−1 of kidney weight after SO (P < 0.05). Bosentan prevented the decrease in glomerular filtration rate (1.0 ± 0.2 ml min−1 g−1 of kidney weight), as well as polyuria and defective concentrating ability, in BDL rats. 3. Plasma ET concentration on day 4 after surgery (28.2 ± 1.5 pmol/l) was higher (P < 0.01) in BDL than in SO rats (12.9 ± 1.5 pmol/l) and rose further in bosentan-treated BDL and SO rats (43.4 ± 5.1 compared with 21.9 ± 6.6 pmol/l). Urinary ET excretion was significantly higher in BDL rats than in SO rats (1.58 ± 0.22 compared with 1.28 ± 0.18 pmol 24h−1 100 g−1 of body weight; P < 0.05). 4. ET synthesis by glomeruli isolated from BDL rats was lower [81 ± 19 fmol h−1 (mg of protein)−1] than that from SO-rats [139 ± 28 fmol h−1 mg of protein)−1; P < 0.05], whereas papillary ET synthesis was higher in BDL [10 ± 3 fmol h−1 (mg of protein)−1] than in SO rats [4 ± 1 fmol h−1 (mg of protein)−1; P < 0.05]. 5. The results indicate that BDL is associated with increased plasma ET concentration and suppression of GFR. Enhanced renal inner medullary collecting-duct ET synthesis, which is reflected by increased urinary ET excretion, may reduce distal tubular water absorption in BDL rats. Increased circulating and renal papillary ET synthesis may thus contribute to renal dysfunction and predispose the kidney to acute renal failure in obstructive jaundice.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hasan M. Al-Dorzi ◽  
Abdulmajeed A. Alsadhan ◽  
Ayman S. Almozaini ◽  
Ali M Alamri ◽  
Hani Tamim ◽  
...  

The performance of glomerular filtration rate- (GFR-) estimating equations was studied against creatinine clearance measured by 24-hour urine collection (CrCl24h-urine) in critically ill patients. Methods. In this substudy of the PermiT trial (https://clinicaltrials.gov/ct2/show/ISRCTN68144998), patients from King Abdulaziz Medical City-Riyadh who had CrCl24h-urine were included. We estimated GFR using Cockroft–Gault (CG), modification of diet in renal disease study (MDRD), chronic kidney disease epidemiology collaboration (CKD-EPI), and Jelliffe equations. For the CG equation, we entered the actual weight in one calculation (CGactual-wt), and if BMI ≥30 kg/m2, we entered the ideal body weight (CGideal-wt) and the adjusted body weight (CGadjusted-wt) in two calculations. We calculated the MDRD equation based on 4 (MDRD-4) and 6 variables (MDRD-6). The performance of these equations was assessed by different ways including Spearman correlation, bias (difference between estimated GFR and CrCl24h-urine), precision (standard deviation of bias), and Bland–Altman plot analysis. Results. The cohort consisted of 237 patients (age 45 ± 20 years, males 75%, mechanically ventilated 99% with serum creatinine 101 ± 94 µmol/L and CrCl24h-urine 108 ± 69 ml/min/1.73 m2). The correlations between the different equations and CrCl24h-urine were modest (r: 0.62 to 0.79; p < 0.0001 ). Bias was statistically significant for CGactual-wt (21 ml/min), CGadjusted-wt (12 ml/min), and MDRD-6 (-10 ml/min) equations. Precision ranged from 46 to 54 ml/min. The sensitivity of equations to correctly classify CrCl24h-urine 30–59.9 ml/min/1.73 m2 was 17.2% for CGactual-wt, 30.0% for CGideal-wt, 31.0% for CGadjusted-wt, 31.0% for MDRD-4, 39.1% for MDRD-6, 13.8% for CKD-EPI, and 34.5% for Jelliffe equation. Conclusions. Commonly used GFR-estimating equations had limited ability to properly estimate CrCl24h-urine and to correctly classify GFR into clinically relevant ranges that usually determine dosing of medications.


2000 ◽  
Vol 98 (4) ◽  
pp. 439-444 ◽  
Author(s):  
A. M. PETERS ◽  
B. L. HENDERSON ◽  
D. LUI

The conventional way in which to scale or index a measurement of glomerular filtration rate (GFR) is to express it in relation to body surface area (BSA). However, BSA may not be appropriate for infants and children because, as individuals increase in size, their relative BSA decreases. Several other whole-body variables have been suggested as alternatives, including extracellular fluid volume (vECF). The purpose of the present study was to compare BSA and vECF as variables against which to index GFR, and in particular to look at this comparison in children versus adults. A total of 130 patients (age range 1–80 years; 40 patients < 12 years) undergoing clinically indicated routine measurement of GFR using the bolus-injection single-compartment technique were included in the study. GFR was measured as the plasma clearance of [51Cr]EDTA as assessed from three peripheral venous blood samples taken between 2 and 4 h after injection of [51Cr]EDTA. Volume of distribution (Vd) was obtained by extrapolation of the clearance curve to zero time. GFR was scaled to a BSA of 1.73 m2. GFR and GFR/1.73 m2 were corrected to account for the assumption of a single compartment. The rate constant of the exponential between 2 and 4 h was also corrected to give GFR/litre ECF. GFR and GFR/1.73 m2 were both divided by GFR/litre ECF, to give vECF and vECF/1.73 m2 respectively. Weight per unit BSA increases as a linear function of BSA. vECF is always less than Vd, on average by about 30%. vECF increased as an exponential function of BSA and as a linear function of body weight. vECF/70 kg body weight was higher in children (16.2±3 litres) than adults (13.4±2.3 litres), but vECF/1.73 m2 was lower in children (9.7±1.7 litres) compared with adults (12.4±2 litres). vECV/1.73 m2 increased as a function of both age and BSA, but vECF/kg decreased. GFR/12.5 litres vECF was higher than GFR/1.73 m2 in children, but these values were similar in adults, with the ratio of these two forms of indexed GFR falling significantly with both age and BSA. Although this was not a normal population, but one with a wide range of renal function, GFR/vECF showed a strong inverse association with age, whereas for GFR/BSA the association was weak. In conclusion, these data provide further evidence that vECF is more valid physiologically for indexing GFR than is BSA, especially in children. Nevertheless, a GFR measurement in a child should ideally be expressed as a percentage of normal for that child's age. However, such normal values are not yet available.


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