Irreversible glomerular damage following heterologous serum albumin overload

Rats injected intraperitoneally with 1 g of bovine serum albumin (BSA) daily for 5 days develop heavy proteinuria and there is swelling and loss of the foot processes of the glomerular epithelial cells. Initially the urinary protein consists of about 55 per cent. BSA and about 40 per cent. rat serum albumin. Proteinuria persists when the injections of BSA are stopped. BSA disappears from the urine and 80-90 per cent. of the urinary protein is rat serum albumin. The persisting proteinuria is caused by glomerular damage resulting from disruption and necrosis of the glomerular epithelial cells leading to complete sclerosis of glomeruli. This damage does not appear to be immunologically determined.