Renal glomerular filtration rate and hepatic blood flow during voluntary diving in Weddell seals

1983 ◽  
Vol 245 (5) ◽  
pp. R743-R748 ◽  
Author(s):  
R. W. Davis ◽  
M. A. Castellini ◽  
G. L. Kooyman ◽  
R. Maue
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Hepatic Blood Flow ◽  
Filtration Rate ◽  
Hepatic Function ◽  
Inulin Clearance ◽  
Weddell Seals ◽  
Icg Clearance ◽  
The Mean

Renal and hepatic function were studied during voluntary dives in Weddell seals by measuring the clearance rate of inulin and indocyanine green (ICG). Inulin is cleared exclusively by the kidneys and measures renal glomerular filtration rate (GFR). ICG is cleared by the liver and is blood flow dependent at concentrations used. Studies were conducted from a portable hut with a trapdoor placed over an isolated hole in the sea ice near McMurdo Station, Antarctica. An intravertebral extradural catheter was inserted percutaneously under light anesthesia in subadult seals weighing 130-200 kg. When released into the ice hole, the seals made voluntary dives, but always had to return to breathe. Serial blood samples were taken after single injections of inulin and ICG and analyzed within 24 h. The mean half time (t 1/2) for inulin clearance while resting at the surface was 27.3 +/- 13.0 min (n = 43) and the mean t 1/2 for ICG clearance was 18.3 +/- 7.3 min (n = 23). The mean resting GFR was 3.6 ml X min-1 X kg-1 (range 3.2-3.9, n = 3). Inulin and ICG clearance rates did not change from resting levels during dives shorter than the seal's aerobic dive limit (ADL). Inulin clearance decreased over 90% during dives longer than the ADL, but there was no significant reduction in ICG clearance during dives lasting up to 23 min. It appears that normal renal GFR and hepatic blood flow continue during natural aerobic dives. During dives that exceed the ADL, GFR is reduced but hepatic blood flow may be maintained.

A single-injection method for measuring glomerular filtration rate

1977 ◽  
Vol 232 (1) ◽  
pp. F72-F76 ◽  
Author(s):  
J. E. Hall ◽  
A. C. Guyton ◽  
B. M. Farr
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Single Injection ◽  
Extracellular Fluid ◽  
Inulin Clearance ◽  
Time Curve ◽  
Single Intravenous Injection ◽  
Injection Techniques ◽  
The Mean

A method for estimating glomerular filtration rate (GFR) has been developed that is based on an analysis of the total area under the plasma radioactivity-time curve after a single intravenous injection of [125I]iothalamate. Glomerular filtration rates obtained by this method (method A) and those obtained with two widely used single-injection techniques, the slope-intercept method (method B), and the two-compartment method (method C), were compared with GFRs obtained by standard inulin clearance techniques in 14 dogs. Method B consistently over. estimated inulin clearances more than 30%. Method C also overestimated inulin clearance considerably in dogs with an increased extracellular fluid volume, but was fairly reliable in normal dogs. Glomerular filtration rates obtained by the new method (method A) were in excellent agreement with inulin clearances in all dogs, regardless of the state of body hydration. The mean inulin clearance for all 14 experiments was 72.7+/-6.0 SE ml/min, while GFRs obtained by method A averaged 75.1+/-6.0 ml/min. The data from this study suggest that method A is a reliable means for estimating GFR that is especially useful in chronic experiments.

125I-Sodium Iothalamate in the Determination of the Glomerular Filtration Rate

1967 ◽  
Vol 06 (03) ◽  
pp. 204-310
Author(s):  
B. Malamos ◽  
A. S. Dontas ◽  
D. A. Koutras ◽  
S. Marketos ◽  
J. Sfontouris ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Clinical Practice ◽  
Creatinine Clearance ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Close Correlation ◽  
Inulin Clearance ◽  
Endogenous Creatinine Clearance ◽  
The Mean

SummaryOne hundred 125I-sodium iothalamate and endogenous creatinine clearances in 36 subjects were compared with standard inulin clearance measurements. There was a very close correlation of the urine/plasma ratios between any two of the three clearances studied, hence both labelled iothalamate and creatinine can be relied upon for the estimation of the glomerular filtration rate in clinical practice. The mean ratio of 125I-sodium iothalamate to inulin clearance was 1.01 and that of creatinine to inulin 1.03. It is concluded that the clearance of 125I-sodium iothalamate can be substituted for the clearance of inulin in clinical determinations of the glomerular filtration rate but that in centres without radioisotope facilities the endogenous creatinine clearance can be used instead.

Distribution of Renal Blood Flow in Patients with Heart Disease

1972 ◽  
Vol 42 (5) ◽  
pp. 627-634
Author(s):  
D. C. Fluck ◽  
T. R. Evans ◽  
D. C. Siggers ◽  
J. Crawley ◽  
S. A. Srivongse
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Filtration Rate ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Component Group ◽  
The Mean

1. The renal blood flow distribution has been studied by the Xe washout method in nineteen patients undergoing routine left-sided cardiac catheterization. 2. It was found that there were two separate groups, one in which the washout curve could be analysed by curve stripping into four exponentials, and one in which only three could be detected. 3. The mean cardiac output was found to be lower in the three-component group, whereas the mean glomerular filtration rate did not differ significantly between the two groups. 4. In the four-component group but not in the three-component group, significant linear correlations were detected between cardiac output and glomerular filtration rate, and between glomerular filtration rate and intrarenal blood flow distribution. 5. One suggestion was that the three component distribution of renal blood flow was associated with increasing renal autoregulation and the maintenance of renal function in the presence of a low cardiac output. 6. A second suggestion was that the differences between the three- and four-component group were primarily due to the more intensive diuretic therapy given to the patients in the three-component group.

scholarly journals Effects of levosimendan on renal blood flow and glomerular filtration in patients with acute kidney injury after cardiac surgery: a double blind, randomized placebo-controlled study

Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Maria Tholén ◽  
Sven-Erik Ricksten ◽  
Lukas Lannemyr
Keyword(s):  
Blood Flow ◽  
Cardiac Surgery ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Filtration Rate ◽  
Kidney Injury ◽  
Controlled Study ◽  
Double Blind ◽  
The Mean

Abstract Background Acute kidney injury (AKI) is a common and serious complication after cardiac surgery, and current strategies aimed at treating AKI have proven ineffective. Levosimendan, an inodilatating agent, has been shown to increase renal blood flow and glomerular filtration rate in uncomplicated postoperative patients and in patients with the cardiorenal syndrome. We hypothesized that levosimendan through its specific effects on renal vasculature, a preferential vasodilating effect on preglomerular resistance vessels, could improve renal function in AKI-patients with who did not have clinical indication for inotropic support. Methods In this single-center, double-blind, randomized controlled study, adult patients with postoperative AKI within 2 days after cardiac surgery, who were hemodynamically stable with a central venous oxygen saturation (ScvO2) ≥ 60% without inotropic support were eligible for inclusion. After randomization, study drug infusions, levosimendan (n = 16) or placebo (n = 13) were given for 5 h. A bolus infusion of levosimendan (12 µg/kg), were given for 30 min followed by 0.1 µg/kg/min for 5 h. Renal blood flow and glomerular filtration rate were measured using infusion clearance of para-aminohippuric acid and a filtration marker, respectively. As a safety issue, norepinephrine was administered to maintain mean arterial pressure between 70–80 mmHg. Intra-group differences were tested by Mann–Whitney U-tests, and a linear mixed model was used to test time and group interaction. Results Twenty-nine patients completed the study. At inclusion, the mean serum creatinine was higher in the patients randomized to levosimendan (148 ± 29 vs 127 ± 22 µmol/L, p = 0.030), and the estimated GFR was lower (46 ± 12 vs 57 ± 11 ml/min/1.73 m2, p = 0.025). Levosimendan induced a significantly (p = 0.011) more pronounced increase in renal blood flow (15%) compared placebo (3%) and a more pronounced decrease in renal vascular resistance (− 18% vs. − 4%, respectively, p = 0.043). There was a trend for a minor increase in glomerular filtration rate with levosimendan (4.5%, p = 0.079), which did differ significantly from the placebo group (p = 0.440). The mean norepinephrine dose was increased by 82% in the levosimedan group and decreased by 29% in the placebo group (p = 0.012). Conclusions In hemodynamically stable patients with AKI after cardiac surgery, levosimendan increases renal blood flow through renal vasodilatation. Trial registration NCT02531724, prospectly registered on 08/20/2015. https://clinicaltrials.gov/ct2/show/NCT02531724?cond=AKI&cntry=SE&age=1&draw=2&rank=1

Reversible Renal Nerve Denervation in the Cat: Effects on Haemodynamic and Excretory Functions of the Ipsilateral and Contralateral Kidneys

1982 ◽  
Vol 63 (s8) ◽  
pp. 215s-217s ◽  
Author(s):  
R. Golin ◽  
A. Stella ◽  
A. Zanchetti
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Renal Nerves ◽  
Renal Nerve ◽  
Contralateral Kidney ◽  
Cooling Period ◽  
Renal Changes ◽  
Water And Sodium Excretion

1. In anaesthetized cats, reversible nenal nerve denervation (cooling of the renal nerves on one side at 4°C for 16 min) was performed and its effects on haemodynamic and excretory functions of the ipsilateral and the contralateral kidneys were studied. 2. Renal nerve cooling did not cause any change in arterial pressure. Slight increase in blood flow, no change in glomerular filtration rate and a large increase in water and sodium excretion occurred in the ipsilateral kidney; simultaneously, no change in blood flow, a slight and transient decrease in glomerular filtration rate, and a significant decrease in diuresis and natriuresis were observed in the contralateral kidney. 3. Ipsilateral and contralateral renal changes were equally evident in the early (minutes 0 to 8) and late phases (minutes 8 to 16) of the cooling period. 4. When renal nerve cooling was repeated after surgical denervation of the contralateral kidney all contralateral effects were abolished.

Effects of growth hormone and IGF-I on renal function in rats with normal and reduced renal mass

1990 ◽  
Vol 259 (5) ◽  
pp. F747-F751 ◽  
Author(s):  
S. B. Miller ◽  
V. A. Hansen ◽  
M. R. Hammerman
Keyword(s):  
Growth Hormone ◽  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Mass ◽  
Filtration Rate ◽  
Inulin Clearance ◽  
Mass Reduction ◽  
Contralateral Kidney ◽  
Igf I

To characterize actions of growth hormone (GH) and insulin-like growth factor ( (IGF-I) on renal function in rats with normal and reduced renal mass, we administered recombinant bovine growth hormone (bGH) or human IGF-I (hIGF-I) to normal rats or to rats that had undergone unilateral nephrectomy and two-thirds infarction of the contralateral kidney, and measured inulin and p-aminohippurate clearances over 10-17 days. Administration of either bGH (100-200 micrograms/day) or hIGF-I (200 micrograms/day) to rats with normal renal mass increased inulin and p-aminohippurate clearances compared with those measured in animals that received vehicle. Filtration fractions were not affected by either bGH or hIGF-I. Inulin clearance was decreased to approximately 17% of normal 1 day after reduction of renal mass in rats. Over the next 3 days insulin clearance increased significantly in rats with reduced renal mass that were administered vehicle. No further enhancement occurred during the next 7 days. Neither bGH nor hIGF-I affected inulin clearance in rats with reduced renal mass. We conclude that both GH and IGF-I enhance glomerular filtration rate when administered to rats with normal renal mass, but not when administered in the same quantities to rats in which renal functional mass is reduced. Glomerular filtration rate increases within 4 days of renal mass reduction independent of exogenous GH or IGF-I.

scholarly journals Albuminuria and glomerular filtration rate in obese children and adolescents

2019 ◽  
Vol 41 (2) ◽  
pp. 193-199
Author(s):  
Luciana Satiko Sawamura ◽  
Gabrielle Gomes de Souza ◽  
Juliana Dias Gonçalves dos Santos ◽  
Fabíola Isabel Suano-Souza ◽  
Anelise Del Vecchio Gessullo ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Children And Adolescents ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Cross Sectional Study ◽  
Systemic Arterial Pressure ◽  
Model Assessment ◽  
Obese Children ◽  
Cross Sectional ◽  
The Mean

Abstract Objective: To describe the frequency of albuminuria in overweight and obese children and adolescents and to relate it to the severity of obesity, pubertal staging, associated morbidities and the glomerular filtration rate. Method: Cross-sectional study including 64 overweight and obese children and adolescents between 5 and 19 years of age. Data collected: weight, height, waist circumference and systemic arterial pressure. Laboratory tests: lipid profile; glycemia and insulin, used to calculate the Homeostasis Model Assessment (HOMA-IR); C-reactive protein; glutamic-pyruvic transaminase and albuminuria in an isolated urine sample (cutoff <30 mg/g). Creatinine was used to calculate the estimated glomerular filtration rate (eGFR, mL/min/1.73 m2). Results: The mean age was 11.6 ± 3.4 years, 32 (50%) and 29 (45.3%) were male and prepubertal. Forty-six (71.9%) had severe obesity. The frequency and median (min/max) of the observed values for albuminuria (> 30 mg/g) were 14 (21.9%) and 9.4 mg/g (0.70, -300.7 mg/g). The mean eGFR was 122.9 ± 24.7 mL/min/1.73 m2. There was no significant correlation between body mass index, pubertal staging, insulin and HOMA-IR with albuminuria values and neither with eGFR. Children with albuminuria tended to have higher values of diastolic blood pressure (75.0 ± 12.2 vs. 68.1 ± 12.4, p = 0.071). Conclusion: Albuminuria, although frequent in children and adolescents with obesity, was not associated with other morbidities and the glomerular filtration rate in these patients.

scholarly journals Profile of estimated glomerular filtration rate of children with Human Immunodeficiency Virus/ Acquired Immune Deficiency Syndrome

2019 ◽  
Vol 6 (5) ◽  
pp. 1931
Author(s):  
Gabriel O. Ezeh ◽  
Oluseyi Oniyangi ◽  
Iretiola B. Babaniyi ◽  
Vincent E. Nwatah ◽  
Felicia U. Eke
Keyword(s):  
Glomerular Filtration Rate ◽  
Hiv Infection ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Developed Countries ◽  
People Living With Hiv ◽  
Schwartz Formula ◽  
Cross Sectional ◽  
Female Ratio ◽  
The Mean

Background: Kidney disease is more common in people of African descent in developed countries. Studies reporting estimate Glomerular Filtration Rate (eGFR) in African populations and people living with HIV have been carried more frequently on adults than children. The study aimed to assess eGFR by use of the SCHWARTZ formula in HIV infected children seen at tertiary hospital.Methods: A descriptive, prospective and cross sectional study of 221 children with HIV infection. Schwartz formula was used to determine eGFR. The main outcome measures were eGFR. The study population comprised HIV infected children attending Paediatric out-patients’ clinic and those admitted into the Paediatric wards, aged between 6 months and 15 years. Data was analysed using SPSS version 20 and results presented in tables and figures. Results: The age range of the study subjects was 12 months to 15 years with the mean age and SD of 8.21±3.61 years. There were 129 (58.4%) male and 92 (41.6%) female children with male to female ratio 1: 0.7.  The mean age for males was 7.87±3.49 years while that for females was 8.70±3.71 years. The eGFR for the study as determined by Schwartz formula had a range of 49.21 to 463.67 ml/ min/ 1.73m2 with the mean of 159.56±59.04 ml/min. The mean eGFR for the males and females were 166.39±63.54ml/ min and 149.99±45.01 ml/ min respectively. Conclusion: The study, in comparison with other studies, observed a lower prevalence of CKD in HIV infected children. Detection of CKD in HIV infection children may be more optimal if combined methods are employed.

Genetic co-segregation of renal haemodynamics and blood pressure in the spontaneously hypertensive rat

1988 ◽  
Vol 74 (1) ◽  
pp. 63-69 ◽  
Author(s):  
S. B. Harrap ◽  
A. E. Doyle
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Filtration Rate ◽  
Spontaneously Hypertensive Rat ◽  
Plasma Renin ◽  
Spontaneously Hypertensive

1. To determine the relevance of renal circulatory abnormalities found in the immature spontaneously hypertensive rat (SHR) to the genetic hypertensive process, glomerular filtration rate and renal blood flow were measured in conscious F2 rats, derived from crossbreeding SHR and normotensive Wistar–Kyoto rats (WKY), at 4, 11 and 16 weeks of age by determining the renal clearances of 51Cr-ethylenediaminetetra-acetate and 125I-hippuran respectively. Plasma renin activity was measured at 11 and 16 weeks of age. 2. Mean arterial pressure, glomerular filtration rate and renal blood flow increased between 4 and 11 weeks of age. Between 11 and 16 weeks the mean glomerular filtration rate and renal blood flow did not alter, although the mean arterial pressure rose significantly. At 11 weeks of age, during the developmental phase of hypertension, a significant negative correlation between mean arterial pressure and both glomerular filtration rate and renal blood flow was noted. However, by 16 weeks when the manifestations of genetic hypertension were more fully expressed, no correlation between mean arterial pressure and renal blood flow or glomerular filtration rate was observed. Plasma renin activity was negatively correlated with both glomerular filtration rate and renal blood flow, but the relationship was stronger at 11 than at 16 weeks of age. 3. These results suggest that the reduction in renal blood flow and glomerular filtration rate, found in immature SHR, is genetically linked to the hypertension and may be of primary pathogenetic importance. It is proposed that the increased renal vascular resistance in these young animals stimulates the rise of systemic arterial pressure which returns renal blood flow and glomerular filtration rate to normal.

Sign in / Sign up

Export Citation Format

Share Document