EXPERIMENTAL proteinuria may be produced in rats by the injection of anti-rat-kidney serum (Smadel, 1936 ; Heymann and Lund, 1951), the injection of the nucleoside of Puromycin (Frenk et al., 1955; Fiegelson et al., 1957) and the injection of uranium nitrate (Magee and Foreman, 1958). I n all three instances proteinuria is thought to result largely from increased permeability of the glomerulus to plasma protein (Spector, 1954; Goodman and Baxter, 1956; Magee and Foreman, 1958; Harkin and Recant, 1958).
METHODSAnti-rat-kidney serum was prepared by a modification of the method of Lippman, Marti and Campbell (1952). Rat kidneys were perfused i n situ via the abdominal aorta with 60 ml. of isotonic saline. The capsule and fat were then removed and the organ homogenised in isotonic saline with a Potter-Elvejhem homogeniser .