Chemical properties of human glomerular basement membrane in the nephropathy with electron dense deposits inside the basement membrane.

Glomerular basement membranes containing electron dense deposits have been isolated from human kidneys. The presence of electron dense material could not be accounted for by the accumulation of an exogenous substance such as gamma globulin. Chemical analyses of abnormal membranes demonstrated that the electron microscopic findings are the consequence of the accumulation of a basement membrane glycoprotein material slightly different from that normally present.