Immunofluorescence Studies on the Anatomic Distribution of the Soluble Antigen Responsible for the Production of Nephrotoxic Serum Nephritis

Abstract

Normal human kidney, lung, aorta, heart, muscle and liver were stained with fluorescein-labeled antiserum to intact human ST-GBM (the tryptic-digested ultrasupernatant substance of intact human glomerular basement membrane) for the purpose of elucidating the anatomic distribution of the specific antigen that is responsible for the production of nephrotoxic serum nephritis. These particular organs were investigated because we have previously demonstrated that antiserum against the ST of these organs (rat) could produce typical glomerulonephritis in rats. The characteristic distribution of fluorescence in these organs was as follows: kidney, glomerular basement membrane and tubular basement membrane; lung, alveolar capillary basement membrane; aorta, probably the sarcolemma of muscle cells in the tunica media; skeletal and cardiac muscle, sarcolemma of muscle cells; and liver, sinusoidal walls. Besides this specific distribution, fluorescence was also found in blood vessels and epithelial basement membrane. Further investigation is necessary to clarify the relationship between the antigenic substance in epithelial basement membrane and the production of nephrotoxic antiserum.