Vividiffusion Experiments on the Ammonia of the Circulating Blood.

The fact that the ammonia content of shed blood under aseptic conditions increases is well known and is taken into account as much as possible by a.rapid procedure in methods for the determination of preformed ammonia. Suggestions as to the source of this slowly liberated ammonia have as yet led to no positive findings. My experiments were undertaken to determine whether with aseptic measures the formation of ammonia occurs in diffusible constituents of the blood after their separation from the non-diffusible constituents according to the vividiffusion method of John J. Abel' and his collaborators. The dialysate, obtained when the vividiffusion apparatus was attached to the femoral artery and femoral vein of a dog for periods varying from three to seven hours, was studied for the production of ammonia in excess of that present at the time of dialysis. The results were compared with those from shed blood under similar conditions. It was found that in a dialysate obtained from circulating blood there is no liberation of ammonia comparable to that which takes place under aseptic conditions in shed blood. Milligrams of Blood NHt-N pr 100 cc. Sample taken at dose of dialysis .................................... 0.30 Sample taken at cose of dialysis and allowed to stand 36 hours......... 0.63