Protein clearances in chronic renal failure: a contribution to the pathophysiology of tubular dysfunction.

Glomerular selectivity is still conserved in chronic renal failure (CRF), although it is poor when compared with non-CRF. In addition, clearances per unit nephron of 15 plasma proteins (Cprot./Ccr X 100) are markedly elevated in CRF. This reflects an effect of osmotic diuresis on tubular reabsorption of proteins, which may partially account for the tubular dysfunction shown by the augmented excretion of the low molecular proteins, such as lysozyme and insulin. Besides this, there exists certainly tubular damage, since tubuloglomerular protein ratio (Clysozyme/Ctransferrin) rises with the progress of glomerular injury.