Excretion and synthesis of basement membrane disaccharide units in Masugi nephritis.

During nephrotoxic nephritis in the rat, an increased urinary excretion of glucosyl-galactosyl hydroxylysine and of galactosyl-hydroxylysine has been observed in the autologous phase of the disease. This due mainly to an elevation of the polypeptide-bound fraction of these hydroxylysyl glucosides with a molecular weight over 1,000 daltons. The levels of both urinary hydroxylysyl glucosides were correlated with proteinuria. Their increased excretion appears to originate in the lysed glomerular basement membrane. At the same stage of nephrotoxic nephritis, an increased glucosyl transferase activity could be demonstrated in the isolated glomeruli, correlated with albuminuria, attesting a higher turn-over of the disaccharide units of the glomerular basement membrane.