Uric Acid, Total Non-Protein Nitrogen and Urea Nitrogen in Blood
(The Figures represent Milligrams per 100 grams of Blood.)
| Uric acid. | Non-protein nitrogen. | Urea nitrogen. | |
|---|---|---|---|
| Rabbit (6 cases) | 0·05 | 31 | 13 |
| Sheep (mixed blood) | 0·05 | 28 | 13 |
| Pig (mixed blood) | 0·05 | 32 | 14 |
| Horse (1 case, anti-toxin animal) | 0·05 | 54 | 28 |
| Monkey (1 case, poliomyelitis) | 0·05 | 60 | 38 |
| Beef (mixed blood) | 0·2 | 24 | 14 |
| Cat (2 cases, diet, liver) | 0·2 | 60 | 34 |
| Cat (2 cases, diet, milk and eggs) | 0·2 | 67 | 37 |
| Cat (2 cases, diet, rice and cream) | 0·2 | 31 | 20 |
| Chicken (6 cases, mixed blood) | 4·9 | 32 | 8 |
| Duck (4 cases, mixed blood) | 4·8 | 34 | 7 |
| Goose (1 case) | 4·8 | 26 | 8 |
The most striking feature of these findings is the marked contrast between the uric acid blood content of mammals as opposed to avians. In the former the amount is minimal—0·2 mg. or less per 100 grams of blood. On the other hand, in the blood of birds, in whose instance the origin of uric acid is so different, it is present in relatively large amounts. As Folin and Denis observe, the small amounts of urea in the blood of birds, as compared with that of mammals, is also worthy of note.
Reverting now to the findings in human subjects, as observed by Folin and Denis, these have been summarised as follows by Walker Hall:—