Mechanical extraction of the water-soluble antigen that induces nephrotoxic antiserum from rat glomerular basement membrane.

Nephrotoxic antibody-inducing antigen was extracted in a water-soluble form with adequate ultrasonic treatment of rat glomeruli. Antiserum against this antigen induced severe proliferative glomerulonephritis when it was injected into rats. This mechanically extracted antigenic material had the character of glycoprotein. Moreover, the immunological and biochemical properties of this antigen were strikingly similar to those of the nephrotoxic antibody-inducing antigen (glycoprotein) which has been obtained with tryptic digestion of GBM. This glycoprotein seems to be an important membrane-unit of normal GBM.