Endothelin-3 Modulates Glomerular Filtration Rate in the Isolated Perfused Rat Kidney

1992 ◽  
Vol 15 (6) ◽  
pp. 325-333 ◽  
Author(s):  
H. Schramek ◽  
C.C. Willinger ◽  
G. Gstraunthaler ◽  
W. Pfaller
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Rat Kidney ◽  
Isolated Perfused Rat Kidney ◽  
Perfused Rat Kidney ◽  
Endothelin 3

Natriuretic and kaliuretic activities of guanylin and uroguanylin in the isolated perfused rat kidney

1998 ◽  
Vol 275 (2) ◽  
pp. F191-F197 ◽  
Author(s):  
Manasses C. Fonteles ◽  
Richard N. Greenberg ◽  
Helena S. A. Monteiro ◽  
Mark G. Currie ◽  
Leonard R. Forte
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Biological Effects ◽  
Rat Kidney ◽  
Second Messenger ◽  
Maximal Increase ◽  
Isolated Perfused Rat Kidney ◽  
Water Homeostasis ◽  
Perfused Rat Kidney

Guanylin and uroguanylin are novel peptides that activate membrane guanylate cyclases found in the kidney and intestine. We compared the effects of these peptides in the isolated perfused rat kidney. Both peptides are natriuretic and kaliuretic in this preparation. Uroguanylin (0.19–1.9 μM) increased glomerular filtration rate from 0.77 ± 0.07 to 1.34 ± 0.3 ml ⋅ g−1⋅ min−1at the highest concentration. A maximal increase in Na+excretion was achieved at 0.66 μM uroguanylin, with a reduction in fractional Na+reabsorption from 78.7 ± 1.7 to 58.8 ± 4.4%. The highest dose of uroguanylin increased kaliuresis by 50%. Osmolar clearance doubled at the highest concentration of uroguanylin tested ( P< 0.05). Guanylin also elicited a natriuresis and kaliuresis but appeared to be less potent than uroguanylin. The highest concentration of guanylin (1.3 μM) decreased fractional Na+reabsorption from 73.9 ± 2.4 to 64.5 ± 4.0%, but lower doses were ineffective. Guanylin stimulated urine K+excretion at the lowest concentration tested (0.33 μM) without any effect on Na+excretion. These peptides may influence salt and water homeostasis by biological effects in the kidney that are mediated by the intracellular second messenger, cGMP.

Removal and excretion of immunoreactive rat growth hormone by the isolated kidney

1981 ◽  
Vol 240 (4) ◽  
pp. F282-F287
Author(s):  
R. Rabkin ◽  
T. I. Gottheiner ◽  
V. S. Fang
Keyword(s):  
Growth Hormone ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Rat Kidney ◽  
Renal Circulation ◽  
Isolated Kidney ◽  
Perfused Rat Kidney ◽  
Rat Growth ◽  
Tubular Absorption ◽  
Organ Clearance

The renal uptake of immunoreactive rat growth hormone (rGH), molecular weight 21,500 daltons, was examined in the isolated perfused rat kidney to determine whether peritubular removal of a protein greater than 12,000 daltons occurs and to assess the functional characteristics of renal GH uptake. Organ clearance of rGH (OCGH) in control kidneys was 1,039 +/- 99 microliters/min and was unaffected by an excess of insulin but markedly depressed by col (10 degrees C( and KCN. Although glomerular filtration rate (GFR) did not differ significantly from OCGH in the control rats, we suspected that filtration could not account for all the rGH removed because of glomerular protein sieving. However, GFR was significantly less than OCGH with cold and KCN treatment, indicating the occurrence of peritubular removal. In nonfiltering kidneys, rGH removal exceeded that of [14C]inulin (P less than 0.05), demonstrating peritubular rGH removal. Tubular absorption of rGH was unaffected by insulin but markedly depressed by cold and KCN. We conclude that rGH is removed from the renal circulation mainly by the glomerular filtration-tubular absorptive pathway, but, in addition, as with smaller proteins, that peritubular removal occurs.

Influence of Contrast Media on Single Nephron Glomerular Filtration Rate in Rat Kidney: A Comparison between Diatrizoate, Iohexol, Ioxaglate, and Iotrolan

1992 ◽  
Vol 33 (6) ◽  
pp. 596-599
Author(s):  
J. Ueda ◽  
A. Nygren ◽  
P. Hansell ◽  
U. Erikson
Keyword(s):  
Glomerular Filtration Rate ◽  
Contrast Media ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Rat Kidney ◽  
Control Value ◽  
Osmotic Effect ◽  
Micropuncture Technique ◽  
Single Nephron

The effects of slow (10 min) i.v. infusions of contrast media (CM, 1 600 mg I/kg b.w.) on single nephron glomerular filtration rate (SNGFR) in the rat kidney were investigated using a micropuncture technique. Diatrizoate, iohexol, or ioxaglate did not change SNGFR, although a tendency towards a transient suppression was seen during the infusion phase. Iotrolan infusion, however, decreased SNGFR (p < 0.05) and the value still remained below the control value 25 min after the start of infusion. Iotrolan is a nonionic dimeric CM and has a lower osmotic effect in the tubules than the ionic dimeric CM and the monomeric CM when given in iodine equivalent doses. These characteristics of iotrolan have probably some influence on the depression of SNGFR after iotrolan injection.

scholarly journals Rapid diagnosis and quantification of acute kidney injury using fluorescent ratio-metric determination of glomerular filtration rate in the rat

2010 ◽  
Vol 299 (5) ◽  
pp. F1048-F1055 ◽  
Author(s):  
Exing Wang ◽  
Ruben M. Sandoval ◽  
Silvia B. Campos ◽  
Bruce A. Molitoris
Keyword(s):  
Acute Kidney Injury ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Fluorescence Probe ◽  
Rat Kidney ◽  
Kidney Injury ◽  
Rapid Diagnosis ◽  
Fluorescent Intensity ◽  
Two Photon

The rapid diagnosis and quantification of acute kidney injury (AKI) severity remain high clinical priorities. By combining intravital fluorescent ratiometric two-photon kidney imaging and the two-compartment pharmacokinetics model, we demonstrate that rapid quantification of glomerular filtration rate (GFR) can be achieved in physiologic and AKI rat kidney models. Using a bolus infusion of a mixture of FITC-inulin and a 500-kDa Texas Red dextran, a full spectrum of GFR values, ranging from 0.17 to 1.12 ml·min−1·100 g−1, was obtained. The GFR values thus determined correlated well with values obtained by the standard 2-h inulin infusion clearance method with a Pearson's correlation coefficient of 0.85. In addition, postischemia deterioration was studied by measuring GFR using the two-photon approach during 24 h following a 45-min bilateral ischemia clamp model. The GFR was found to decline sharply during the initial 4 h followed by a nadir with little sign of rising over the ensuing 24-h period. Moreover, a FITC-labeled 5-kDa dextran was identified as having nearly identical filtration characteristics as FITC-inulin, but had markedly increased fluorescent intensity, thus minimizing the quantity needed for individual studies. The technique reported allows for very rapid GFR determinations, within 10–15 min, based on plasma clearance of a freely filtered fluorescence probe, instead of a prolonged one-compartment interstitial space reporter molecule clearance employed by other technologies.

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