Molecular sieving by glomerular basement membrane isolated from normal and nephrotic rabbits.

Analog chromatography with glomerular basement membrane isolated from normal and nephrotic rabbits was performed to see if there was a molecular sieving effect by the basement membrane. In a normal glomerular basement membrane column, 125I-labeled human serum globulin and 131I-labeled human serum albumin were eluted at the same position, probably at the void volume of the column. However, 125I-labeled insulin and tritiated water appeared with a delay and gave separated peaks. In nephrotic glomerular basement membrane, 125I-labeled human globulin, 131I-labeled serum albumin, 125I-labeled insulin and tritiated water gave four distinctly separated peaks in that order. By analogy with Sephadex, the sieving effect of glomerular basement membrane was demonstrated.