Dextran clearance as a measure of glomerular permeability a preliminary note

Wallenius, G

doi:10.3109/00365515209060638

Cited by 33 publications

(46 citation statements)

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“…This value agrees well with that predicted from the glomerular permeability values obtained for inert macromolecules having a comparable size (45)(46)(47).…”

Section: Discussionsupporting

confidence: 81%

The renal handling of low molecular weight proteins

Waldmann¹,

Strober²,

Mogielnicki³

1972

J. Clin. Invest.

235

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A B S T R A C T The present study was directed toward determining the role of the kidney in the metabolism of various classes of serum proteins and to define the urinary protein excretion patterns and the pathogenesis of disorders of protein metabolism in patients with proteinuria. To this end, the metabolic fates of a small protein, X-L chain (mol wt 44,000), and a protein of intermediate size, IgG (mol wt 160,000), were studied in controls and patients with renal disease. Controls metabolized 0.28%/hr of circulating IgG and 22.3%/hr of circulating X-L chain. All the IgG and 99% of the X-L chain was catabolized with the remaining X-L chain lost intact into the urine. The kidney was shown to be the major site of catabolism for small serum proteins. Three distinct disorders of protein metabolism were noted in patients with renal tubular disease and tubular proteinuria, glomerular disease (the nephrotic syndrome), and disease involving the entire nephrons (uremia), respectively. Patients with renal tubular disease had a 50-fold increase in the daily urinary excretion of 1540,000 molecular weight proteins such as lysozyme and X-L chains. Serum IgG and X-L chain survivals were normal; however, the fraction of the over-all X-L chain metabolism accounted for by proteinuria was increased 40-fold whereas endogenous catabolism was correspondingly decreased. Thus, tubular proteinuria results from a failure of proximal tubular uptake and catabolism of small proteins that are normally filtered through the glomerulus. Patients with the nephrotic syndrome had a slight increase in X-L chain survival whereas IgG survival was decreased and the fraction of IgG lost in the urine was An abstract of this work appeared in J. Clin. Invest. 1970. 49: 99a. (Abstr.)

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“…This value agrees well with that predicted from the glomerular permeability values obtained for inert macromolecules having a comparable size (45)(46)(47).…”

Section: Discussionsupporting

confidence: 81%

The renal handling of low molecular weight proteins

Waldmann¹,

Strober²,

Mogielnicki³

1972

J. Clin. Invest.

235

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“…Clearance of dextran in this dog was 0.6 ml/min and compared with the normal inulin clearance under these conditions of approximately 60 ml/min indicates that less than 1% of the circulating dextran was filtered. This value agrees with the observation of Wallenius that no dextran of molecular weight exceeding 55,000 appears in the urine (9). (3) Control solution: To evaluate the effect of the salt and fluid volume associated with the albumin and dextran solutions, a 127 mEq/liter of NaCl solution was infused in the same manner as the albumin and dextran solutions and recollection samples were obtained from five dogs.…”

Section: Methodssupporting

confidence: 64%

Depression of fractional sodium reabsorption by the proximal tubule of the dog without sodium diuresis

Howards¹,

Davis²,

Knox³

et al. 1968

J. Clin. Invest.

104

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A B S T R A C T The effect of infusions of hyperoncotic solutions on fractional sodium reabsorption by the pro)imal tubule of the dog was studied by the recollection micropuncture method. Tubule fluid to plasma inulin concentration ratios were measured for identified proximal tubule segments before and after infusion of 25%o albumin or dextran solutions. Results were compared with changes in fractional reabsorption during saline diuresis. Plasma volume increased 66% + SE 5.8 after infusion of albumin solution and 94% + SE 8.2 after infusion of dextran solution. Fractional sodium reabosorption by the proximal tubule was depressed after infusion of both of these hyperoncotic solutions. Nevertheless, changes in sodium excretion after infusion of albumin and dextran were small. In contrast, after infusions of isotonic sodium chloride solution, which increased plasma volume 61 % + SE 5.8, a decrease in fractional reabsorption of 50.7%o + SE 7.2 was associated with large changes in sodium excretion.

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“…Factors other than size and shape that may also influence the rate of diffusion of a molecule through a membrane (4) are considered negligible. Although indirectly applicable to proteins, clearance studies in animals utilizing dextrans of varying molecular weight (5,6) have demonstrated the distribution of "pore size" in the normal glomerulus within a range of molecular weights from 5,000 to 85,000. In addition, these studies confirm the relationship between clearance of a molecule and its molecular weight.…”

mentioning

confidence: 99%