AMINO NITROGEN CHANGES OF THE BLOOD IN NEPHRITIS

Amino nitrogen and peptide nitrogen content of the blood in nephritic patients have been frequently determined since the introduction of suit-able micro methods. Gasometric determinations of amino nitrogen and peptide nitrogen of plasma and red blood cells separately have, however, not yet been done. That colorimetric analyses of the same blood samples give lower results for amino acid nitrogen than the gasometric method or the formaldehyde titration, and that colorimetric recovery of amino acids added to blood is incomplete, have been reported by Van Slyke and Kirk (18). The use of different analytical methods may accordingly explain the conflicting results reported in the literature. Thus most observers using the colorimetric method of Folin (Berglund (2), Greene, Sandiford and Ross (6), Schmidt (16), Witts (20), Feinblatt and Shapiro (5)) found no deviation from the normal in series of patients with nephritis, including several cases of uremia. Slightly or moderatel