The Determination of Ammonia in Blood and Other Biological Fluids

In 1912 Folin and Denis (1) published a series of methods for the analysis of blood and urine, all based on the principle of Nesslerization, and among those met.hods was one for the determination of ammonia in blood. By the help of this method Folin and Denis proved the then important point t.hat the relatively high ammonia content of portal blood is mostly putrefactive ammonia absorbed from the gut. After having further found by a general survey t’hat nothing else of physiological or clinical significance could be elucidated by the method we lost interest in it, and we failed to grasp t’he fact that the blood ammonia values found by the new method might be too small to account for the very large quantities of ammonium sa1t.s occurring in urine. Several years later, in 1921, Nash and Benedict (2) seemingly proved by substantially the same method that the ammonia found in urine must be liberated in the kidneys. Bliss (3), at my suggestion, repeated the essential parts of t.he work of Nash and Benedict and confirmed their finding that the blood of the renal arteries contains less ammonia than the blood of the renal veins. Later, Bliss continued t’he work from a new point of view, and he has endeavored to prove that there is probably ammonia formation in all Cssues, but that this ammonia, originally used to neutralize acids formed in the tissues, is carried in the blood in the form of amide nitrogen contained in the blood protein of the corpuscles from which it is liberated as ammonia in the kidneys. This paper has no bearing on the controversy over the validity of Bliss’ findings and interpretations.