Clearance Methods in the Rat

1978 ◽  
pp. 23-40 ◽  
Author(s):  
Susan Opava Stitzer ◽  
Manuel Martinez-Maldonado
Keyword(s):  
2018 ◽  
Vol 55 (3) ◽  
pp. 332-334 ◽  
Author(s):  
Andra Elena Balcangiu Stroescu ◽  
Maria Daniela Tanasescu ◽  
Alexandru Diaconescu ◽  
Laura Raducu ◽  
Daniela Gabriela Balan ◽  
...  

The survival of CKD patients has known significant improvement with the appearance of extrarenal clearance methods. Being a domain in a rapid progression, the hemodialysis membranes have been, in time, one of the key modifying points. In this paper will make a short presentation of the features of hemodialysis membranes and will point out aspects which need future research.


1995 ◽  
Vol 59 (3) ◽  
pp. 614-620 ◽  
Author(s):  
David J. Cook ◽  
Robert E. Anderson ◽  
John D. Michenfelder ◽  
William C. Oliver ◽  
Thomas A. Orszulak ◽  
...  

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Ashish Bhoyar ◽  
Vinant Bhargava ◽  
Ashwani Gupta ◽  
Anurag Gupta ◽  
Vaibhav Tiwari ◽  
...  

Abstract Background and Aims Glomerular filtration rate (GFR) is estimated traditionally from 24-hour urinary creatinine clearance. Creatinine is mainly filtered by glomerulus. The collection of 24-hour urinary sample is a difficult task with many patients fail to collect all the urine samples. As measuring GFR is cumbersome, expensive, and not easily available in all centers, various equations are developed for estimating GFR from creatinine like MDRD, CKD EPI creatinine. GFR obtained from serum creatinine shows wide variation as muscle mass and dietary protein intake are important determinants of serum creatinine concentration. Literature shows very few studies with GFR estimation with reference to age in Indian population. Hence, this study is planned to develop age specific nomogram for GFR in healthy kidney donor population as well as to study agreement between GFR obtained by 99m Tc DTPA three sample method and GFR estimated by 24-hour urinary creatinine. The aim of this stidy was to develop age-specific nomogram GFR in healthy kidney donor population and to study the agreement between the GFR measured by Technetium-99m diethylene triamine pentaacetic acid (99m Tc DTPA) and 24-hour urinary creatinine method. Method This study was conducted at Sir Ganga Ram hospital, New Delhi. All healthy individuals aged more than 20 years and less than 65 years, undergoing evaluation as prospective kidney donor at our hospital were the part of this study. GFR was measured by 99m Tc DTPA clearance using 3 sample method. GFR measured by DTPA method was used to develop nomogram. Creatinine Clearance was calculated from 24-hour urinary creatinine by formula U x V/P where, U is urinary creatinine level, P is plasma creatinine level and V is total volume of urine. Nomogram was developed with respect to these 3 Age groups; namely, 20 to 40 years, 40 to 50 years and 50 to 65 years Results Total 100 kidney donors were included in this study. Enrolled subjects were divided into 3 age groups; 20 to 40 years (n=28), 40 to 50 years (n=46) and 50 to 65 years (n=26). Majority of the donors were females (n=80). The agreement between GFR obtained by 99m Tc DTPA and 24-hour urinary creatinine clearance methods was 92.6 vs. 94 ml/min, 80.4 vs. 76 ml/min and 76.3 vs. 70 ml/min in respective age groups. Conclusion In the younger age group (20 to 40 years), there is better agreement in GFR measured by 99m Tc DTPA method and 24-hour urinary creatinine clearance methods.


1962 ◽  
Vol 64 (5) ◽  
pp. 661-665 ◽  
Author(s):  
Jay N. Cohn ◽  
Thomas E. Liptak ◽  
Edward D. Freis

2020 ◽  
Vol 319 (2) ◽  
pp. F323-F334
Author(s):  
Lei Yang ◽  
Gustavo Frindt ◽  
Yuanyuan Xu ◽  
Shinichi Uchida ◽  
Lawrence G. Palmer

We investigated the regulation of Na+ and K+ excretion and the epithelial Na+ channel (ENaC) in mice lacking the gene for aldosterone synthase (AS) using clearance methods to assess excretion and electrophysiology and Western blot analysis to test for ENaC activity and processing. After 1 day of dietary Na+ restriction, AS−/− mice lost more Na+ in the urine than AS+/+ mice did. After 1 wk on this diet, both genotypes strongly reduced urinary Na+ excretion, but creatinine clearance decreased only in AS−/− mice. Only AS+/+ animals exhibited increased ENaC function, assessed as amiloride-sensitive whole cell currents in collecting ducts or cleavage of αENaC and γENaC in Western blots. To assess the role of aldosterone in the excretion of a K+ load, animals were fasted overnight and refed with high-K+ or low-K+ diets for 5 h. Both AS+/+ and AS−/− mice excreted a large amount of K+ during this period. In both phenotypes the excretion was benzamil sensitive, indicating increased K+ secretion coupled to ENaC-dependent Na+ reabsorption. However, the increase in plasma K+ under these conditions was much larger in AS−/− animals than in AS+/+ animals. In both groups, cleavage of αENaC and γENaC increased. However, Na+ current measured ex vivo in connecting tubules was enhanced only in AS+/+ mice. We conclude that in the absence of aldosterone, mice can conserve Na+ without ENaC activation but at the expense of diminished glomerular filtration rate. Excretion of a K+ load can be accomplished through aldosterone-independent upregulation of ENaC, but aldosterone is required to excrete the excess K+ without hyperkalemia.


1986 ◽  
Vol 6 (4) ◽  
pp. 481-485 ◽  
Author(s):  
U. I. Tuor ◽  
W. Fitch ◽  
D. I. Graham ◽  
A. D. Mendelow

The relationships between CBF in gray and white matter to those of the fast and slow components of xenon-133 clearance curves remain uncertain. CBF was measured in 13 anaesthetized baboons under a variety of conditions, using both the xenon-133 clearance technique and [14C]iodoantipyrine quantitative autoradiography. There was a linear relationship between CBF, as determined by the stochastic (height/area) analysis of the clearance curve, and mean CBF determined from the autoradiograms ( r = 0.94, p < 0.001, slope = 0.86 ± 0.09). There was also a linear correlation between the fast-flow component (measured with xenon-133) and blood flow in the cerebral gray matter (measured with [14C]iodoantipyrine) ( r = 0.92, p < 0.001, slope = 0.69 ± 0.15) and between the slow-flow component (with xenon-133) and blood flow in white matter (with [14C]iodoantipyrine) ( r = 0.79, p < 0.01, slope = 0.81 ± 0.10). In the primate brain, the fast- and slow-flow indices therefore appear to be representative of CBF in gray matter and white matter, respectively, whereas the stochastic analysis provides a stable measure of mean CBF within the tissue monitored.


1964 ◽  
Vol 206 (6) ◽  
pp. 1379-1383 ◽  
Author(s):  
Joseph M. Letteri ◽  
Laurence G. Wesson

The effects of mercaptomerin on Tmpah in man and the pentobarbital-anesthetized dog were studied by standard clearance methods. Tmpah was depressed to 60% of control values during the 4th to 6th hr of pentobarbital anesthesia. Mercaptomerin administration to the pentobarbitalized dog prevented the depressant effect of pentobarbital on Tmpah from appearing, in that no significant difference in Tmpah was noted between control periods and postmercurial periods in these experiments. Injection of dimercaprol to pentobarbitalized animals receiving mercaptomerin depressed Tmpah to values expected in anesthetized animals which had received no mercaptomerin. Dimercaprol had no effect in anesthetized animals not receiving mercaptomerin. In man, mercaptomerin depressed Tmpah to 50% of control values whether the mercurial was injected before or after commencement of PAH-loading.


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