In a recent communication1 it was shown that uremia could be reproduced in its minutest details in the presence of normal kidneys. Suppression of urine was previously shown to occur, not because the kidneys became impermeable but because the water was held in a firmer combination with the colloids of the blood and tissues.2 The nitrogen retention cannot be the cause of nephritic syndromes, as many cases of uremia in which the blood nitrogen values were normal have been reported in the recent literature. Again, suppression of urinary excretion per se for very long periods (over three weeks) has not caused uremic manifestations either experimentally or clinically.
With these points in view the urinary proteins were studied not only in cases of experimental uremia but in ether nephritides in dogs. Small samples were collected every ten to fifteen minutes, and each sample that contained protein was tested against
ANDREWS E, THOMAS WA. THE ORIGIN OF URINARY PROTEINS. JAMA. 1928;90(7):539-540. doi:10.1001/jama.1928.02690340041016