Lysine Infusion in Cystinuria: Theoretical Renal Thresholds for Lysine

1973 ◽  
Vol 44 (2) ◽  
pp. 99-111 ◽  
Author(s):  
Frances T. Lester ◽  
D. C. Cusworth
Keyword(s):  
Amino Acids ◽  
Intravenous Infusion ◽  
Tubular Reabsorption ◽  
Water Diuresis ◽  
Renal Handling ◽  
The Third ◽  
Lysine Concentration ◽  
Renal Tubular Reabsorption ◽  
Renal Tubular ◽  
Normal Adults

1. The renal handling of lysine was studied during the intravenous infusion of a lysine load given in such a way that the plasma lysine concentration was constantly increasing. Theoretical renal thresholds, and maximum rates of renal tubular reabsorption of lysine, have been determined in three normal adults, five homozygous cystinuric patients, and three persons, two ‘completely’ and the third ‘incompletely’ recessive, heterozygotes for cystinuria. All the cystinuric patients were found to have thresholds at less than 1 mg of lysine/100 ml of plasma; the thresholds of all three heterozygotes fell within the same range as those of the three normal persons, that is, at values only two to three times the fasting plasma lysine concentration. 2. Not only was the lysine load shown to greatly increase the excretion of cystine, arginine and ornithine in the normal and heterozygous persons, but it was also shown to increase the already high clearance of these three amino acids in three of the homozygous cystinuric patients. 3. It was shown that a water diuresis alone will not cause increased excretion of any amino acids except taurine.

Renal Vasodilatation: Effect on Renal Handling of Phosphate

1971 ◽  
Vol 41 (2) ◽  
pp. 109-121 ◽  
Author(s):  
J. J. Ahumada ◽  
S. G. Massry
Keyword(s):  
Tubular Reabsorption ◽  
Combined Effects ◽  
Renal Handling ◽  
Sodium Calcium ◽  
Reabsorptive Capacity ◽  
Renal Tubular Reabsorption ◽  
Calcium Magnesium ◽  
Calcium And Magnesium ◽  
Renal Tubular ◽  
Filtered Load

1. The combined effects of unilateral renal vasodilatation produced by acetylcholine or bradykinin and intravenous infusion of angiotensin on phosphate excretion and reabsorption were investigated in fourteen anaesthetized dogs. The influence of these manoeuvres on the excretion of sodium, calcium and magnesium was also evaluated. 2. Unilateral renal vasodilatation alone produced an increase in the excretion of phosphate, calcium, magnesium and sodium; and the infusion of angiotensin caused further augmentation of the excretory rates of these ions from the vasodilated kidney in most experiments. 3. The maximal tubular reabsorptive capacity (Tm) for phosphate was decreased by renal vasodilatation. 4. There was a close and significant correlation between the fraction of the filtered load of phosphate, calcium, and magnesium which was excreted and that of sodium. 5. The results indicate that renal vasodilatation with or without the infusion of angiotensin causes a decrease in the renal tubular reabsorption of phosphate, calcium, magnesium and sodium.

Effect of parathyroid hormone on renal tubular reabsorption of amino acids

Metabolism ◽  
1974 ◽  
Vol 23 (8) ◽  
pp. 715-727 ◽  
Author(s):  
Elizabeth M. Short ◽  
Louis J. Elsas ◽  
Leon E. Rosenberg
Keyword(s):  
Amino Acids ◽  
Parathyroid Hormone ◽  
Tubular Reabsorption ◽  
Renal Tubular Reabsorption ◽  
Renal Tubular

Effect of Various Amino Acids on the Renal Tubular Reabsorption of Inorganic Sulfate in the Dog

1956 ◽  
Vol 185 (3) ◽  
pp. 539-542 ◽  
Author(s):  
Fredrik Berglund ◽  
William D. Lotspeich
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Tubular Reabsorption ◽  
Acid Inhibition ◽  
Maximal Rate ◽  
Renal Tubular Reabsorption ◽  
Renal Tubular ◽  
Inorganic Sulfate

Various amino acids depress the sulfate-Tm in the dog. The effects of l-alanine, glycine, d-alanine and l-arginine are compared. The capacity of any one of these amino acids to depress sulfate-Tm correlates directly with maximal rate of reabsorption of the amino acid. The nature of the amino acid inhibition, its relation to amino acid reabsorption, the amino-acidurias and some general problems of renal tubular reabsorption are discussed.

Effects of Phenylalanine Analogues on Renal Tubular Reabsorption of Amino Acids in the Rat

1977 ◽  
Vol 53 (4) ◽  
pp. 355-364
Author(s):  
C. W. I. Owens
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Concentrations ◽  
Tubular Reabsorption ◽  
Urinary Flow ◽  
Serial Determination ◽  
Forced Diuresis ◽  
Renal Tubular Reabsorption ◽  
Renal Tubular

1. A method is described for the serial determination of renal tubular reabsorption of amino acids in the ethanol-anaesthetized rat. It utilizes intravenous radio-labelled inulins, automated amino acid analysis and forced diuresis. 2. Intravenous loading with phenylalanine and infusion of phenylalanine analogues in this preparation decrease reabsorption of endogenous amino acids in accordance with existing concepts of amino acid transport. 3. Maximal tubular reabsorption (Tmax.) could not be demonstrated for phenylalanine at plasma concentrations below 9 mmol/l. 4. Infusion of phenylalanine analogues into phenylalanine-loaded (‘phenylketonuric’) rats did not specifically inhibit tubular reabsorption of phenylalanine and it is unlikely that any of the substances tested have a potential therapeutic use in man. 5. p-Guanidino derivatives of phenylalanine, in contrast to p-amino derivatives, appear to cause a dose-related basic aminoaciduria. 6. Consideration of urinary flow rates and sodium excretion suggests that the ethanol anaesthesia does not modify amino acid reabsorption through effects on sodium transport or antidiuretic hormone.

INHIBITORY EFFECT OF CERTAIN AMINO ACIDS ON RENAL TUBULAR ABSORPTION OF PHOSPHATE

1967 ◽  
Vol 45 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Alfred F. Michael ◽  
Keith N. Drummond
Keyword(s):  
Amino Acids ◽  
Parathyroid Hormone ◽  
Inhibitory Effect ◽  
Tubular Reabsorption ◽  
Hormone Action ◽  
Basic Amino Acids ◽  
Phosphate Excretion ◽  
Renal Tubular Reabsorption ◽  
Tubular Absorption ◽  
Renal Tubular

Infusion of certain neutral L-amino acids (alanine, glycine, valine, and tryptophan) into dogs resulted in an inhibition of the renal tubular reabsorption of phosphate and increased phosphate excretion. This was seen in both the parathyroidectomized animal and under conditions of exogenous parathormone infusion, indicating that the phosphaturia induced by amino acids is independent of parathyroid hormone action. This effect was stereospecific and did not occur with D-alanine; no effect was observed after infusion of the basic amino acids L-arginine and L-lysine.

scholarly journals THE CONTROL OF THE RENAL EXCRETION OF WATER

1942 ◽  
Vol 76 (4) ◽  
pp. 387-399 ◽  
Author(s):  
James A. Shannon
Keyword(s):  
Experimental Data ◽  
Diabetes Insipidus ◽  
Antidiuretic Hormone ◽  
Intravenous Infusion ◽  
Renal Excretion ◽  
Tubular Reabsorption ◽  
Posterior Pituitary ◽  
Hormone Administration ◽  
Renal Tubular Reabsorption ◽  
Renal Tubular

1. The administration of the posterior pituitary antidiuretic hormone by constant intravenous infusion has been used to examine the two characteristic actions of the hormone; namely, the facilitation of the active renal tubular reabsorption of water distally in the nephron and the inhibition of the renal tubular reabsorption of sodium proximally. 2. Experimental evidence was obtained which indicates that variations in the excretion of water and electrolyte involve the integration of these two actions with obscure variables which are discemible in the experimental data but are not subject to definition at this time. 3. Graded antidiuresis in the animal with diabetes insipidus, when normally hydrated, was only obtained in the range of 0.001 to 0.005 unit (pressor) per hour. This range of hormone administration was also found to be physiologically active in the normal animals. These observations together with others permit the placing of the normal rate of liberation of the antidiuretic hormone in a10 to 15 kilo dog in the range of 0.001 to 0.005 unit per hour.

Renal Handling of Beta2-Microglobulin in Patients with Cystic Fibrosis

DICP ◽  
1989 ◽  
Vol 23 (12) ◽  
pp. 1013-1017 ◽  
Author(s):  
Gregory L. Kearns ◽  
Phillip L. Berry ◽  
Joseph A. Bocchini ◽  
Bettina C. Hilman ◽  
John T. Wilson
Keyword(s):  
Cystic Fibrosis ◽  
Creatinine Clearance ◽  
Fractional Excretion ◽  
Tubular Reabsorption ◽  
Hospitalized Patients ◽  
Normal Children ◽  
Renal Handling ◽  
Renal Tubular Reabsorption ◽  
Proximal Tubular ◽  
Renal Tubular

We evaluated the renal handling of beta2-microglobulin (β2-M) and creatinine in healthy outpatients (n = 6), normal children hospitalized for infections treated with antibiotics (not including an aminoglycoside) (n = 4); outpatients with cystic fibrosis (CF; n = 12), and hospitalized patients with CF (n = 6) who received a 10- to 14-day course of antibiotic treatment that included an aminoglycoside. The serum β2-M concentrations in the normal outpatients (2020.1 ± 276.6 μg/L) were significantly lower (p <0.05) than those observed for outpatients (2833.3 ± 202.6 μg/L) or patients with CF (2861.8 ± 340.5 μg/L. There were no significant differences found for creatinine clearance or fractional excretion of β2-M when subjects without CF were compared with those with the disease. Furthermore, no significant differences were observed in hospitalized patients with CF when creatinine clearance and fractional excretion of β2-M were compared between the initiation and conclusion of aminoglycoside treatment. Glomerular filtration and proximal tubular reabsorption of β2-M were not altered in patients with CF. These findings do not support a global defect in proximal renal tubular reabsorption as the underlying cause for altered aminoglycoside clearance in patients with CF.

Renal Excretion of Radioiodide in the Dog

1956 ◽  
Vol 187 (3) ◽  
pp. 529-535 ◽  
Author(s):  
Gerhard Giebisch ◽  
Martha B. MacLeod ◽  
Frederic Kavaler
Keyword(s):  
Renal Excretion ◽  
Indirect Evidence ◽  
Tubular Reabsorption ◽  
Water Reabsorption ◽  
Water Diuresis ◽  
Osmotic Diuresis ◽  
Sodium Salts ◽  
Nonspecific Effects ◽  
Renal Tubular Reabsorption ◽  
Renal Tubular

Radioiodide and creatinine clearances were measured simultaneously in dogs. Osmotic diuresis was induced by loading with mannitol, sodium salts of various anions such as chloride, bromide, iodide, nitrate and ferrocyanide, and by the administration of mercurial diuretics. Results of these experiments are compared with those obtained during water diuresis. No evidence for active tubular reabsorption of radioiodide could be observed. Renal tubular reabsorption of I131 was found to be chiefly determined by the degree of tubular water reabsorption and hence the transtubular diffusion gradient of radioiodide. Nonspecific effects of other anions in the tubular urine may modify passive tubular reabsorption: anions less readily reabsorbed displace I131 from the urine and depress its renal clearance. Indirect evidence suggests that about 95% of filtered radioiodide is reabsorbed at a tubular site proximal to that of final water reabsorption.

scholarly journals Early post-transplantation hypophosphatemia is associated with elevated FGF-23 levels

2011 ◽  
Vol 164 (5) ◽  
pp. 839-847 ◽  
Author(s):  
Andrea Trombetti ◽  
Laura Richert ◽  
Karine Hadaya ◽  
Jean-Daniel Graf ◽  
François R Herrmann ◽  
...  
Keyword(s):  
Renal Transplantation ◽  
Tubular Reabsorption ◽  
Phosphate Metabolism ◽  
Multivariate Models ◽  
Intact Pth ◽  
Post Transplantation ◽  
Estimated Gfr ◽  
Renal Tubular Reabsorption ◽  
Renal Tubular ◽  
Fgf 23

BackgroundWe examined the hypothesis that high FGF-23 levels early after transplantation contribute to the onset of hypophosphatemia, independently of parathyroid hormone (PTH) and other factors regulating phosphate metabolism.MethodsWe measured serum phosphate levels (sPi), renal tubular reabsorption of Pi (TmPi/GFR), estimated GFR (eGFR), intact PTH (iPTH), calcitriol, intact (int) and C-terminal (Cter) FGF-23, dietary Pi intake and cumulative doses of glucocorticoids in 69 patients 12 days (95% confidence interval, 10–13) after renal transplantation.ResultsHypophosphatemia was observed in 43 (62%) of the patients 12 days after transplantation. Compared with non-hypophosphatemic subjects, their post-transplantation levels of intact and CterFGF-23 were higher (195 (108–288) vs 48 (40–64) ng/l, P<0.002 for intFGF-23; 205 (116–384) vs 81 (55–124) U/ml, P<0.002, for CterFGF-23). In all subjects, Cter and intFGF-23 correlated inversely with sPi (r=−0.35, P<0.003; −0.35, P<0.003, respectively), and TmPi/GFR (r=−0.50, P<0.001; −0.54, P<0.001, respectively). In multivariate models, sPi and TmPi/GFR were independently associated with FGF-23, iPTH and eGFR. Pre-transplant iPTH levels were significantly higher in patients developing hypophosphatemia after renal transplantation. Pre-transplant levels of FGF-23 were not associated with sPi at the time of transplantation.ConclusionIn addition to PTH, elevated FGF-23 may contribute to hypophosphatemia during the early post-renal transplant period.

Renal tubular reabsorption of trace alkaline earths compared with calcium

1965 ◽  
Vol 208 (6) ◽  
pp. 1165-1170 ◽  
Author(s):  
W. Joseph Rahill ◽  
Mackenzie Walser
Keyword(s):  
Protein Binding ◽  
Transport Mechanism ◽  
Tubular Reabsorption ◽  
Constant Infusion ◽  
Constant Power ◽  
Calcium Clearance ◽  
Renal Tubular Reabsorption ◽  
Order Of Magnitude ◽  
Alkaline Earths ◽  
Renal Tubular

Simultaneous clearances of inulin, calcium, and either Be7, Ba140, or Ra226, given by constant infusion, were measured in salt-depleted dogs or dogs undergoing mild saline, mannitol, or sulfate diuresis. Urine-to-plasma ratios of all three cations less than 0.5 were noted, suggesting that all can be actively reabsorbed. Clearances of barium and radium were correlated with calcium clearance, but the clearance of beryllium was unpredictable. Protein binding of beryllium was shown to be of the same order of magnitude as other alkaline earths when errors due to adsorption of Be7 onto containers were minimized. Protein binding of barium averaged 54%. The excreted-to-filtered ratio for barium was a constant power (.54) of the ratio for calcium. The data do not exclude the possibility that these cations are reabsorbed by a common transport mechanism with calcium.

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