Nephrotoxicity and Studies on the Reabsorption and Disposal of Alpha 2U-Globulin
Alpha-2u-globulin, a low-molecular weight (LMW) protein of 19,000 dalton, is synthesised by the male rat liver as a family of isoforms; pI = 4.6–5.2. This protein is an important constituent of the physiological proteinuria in adult male rats. At maturity the total urinary protein is 20–30% alpha-2u and 10% albumin. At 160 days of age the excretion of albumin and total urinary proteins are markedly increased. By one year, albumin represents nearly 60% of the total protein while alpha-2u is less than 10%. This reversal in relative content may be the consequence of a progressive glomerulonephrosis, associated with an apparent spontaneous accumulation of hyaline droplets. The nephrotic condition may be the consequence of the burden of excreting alpha-2u. Its early onset is sexdependent; female rats do not exhibit the proteinuria until a later age.
KeywordsExcretion Rate Tranexamic Acid Lysyl Residue Renal Tubule Cell Total Urinary Protein
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- 1.O.W. Neuhaus, Renal reabsorption of low-molecular weight proteins in adult male rats: alpha-2u globulin, Proc. Soc. Expt. Biol. Med. 182:531 (1986) .Google Scholar
- 2.B.E. Sumpio and T. Maack, Kinetics, competition and selectivity of tubular absorption of proteins, Am. J. Physiol. 243:F379 (1982).Google Scholar
- 3.K. Baumann, C. Cojocel and W. Pape, Effect of molecular charge of protein on its reabsorption in microperfused proximal renal tubules, In: “The Pathogenicity of Cationic Proteins”, P.P. Lambert, P. Bergmann and R. Beauwens, eds., Raven Press, New York (1983).Google Scholar
- 4.C.E. Mogensen, K. Soiling and E. Vittinghus, Studies on mechanisms of proteinuria using amino acid-induced inhibition of tubular reabsorption in normal and diabetic man, In “Contributions to Nephrology”, G.M. Berlyne, S. Giovannetti and S. Thomas, eds., S. Karger, Basel (1981).Google Scholar