Experimental Uranium Nephritis. 



133 



dition. The possible etiological bearing of the retention of 

 creatinine is being considered from the standpoint of experimental 

 nephritis. 



Estimations of total solids, total nitrogen, chlorides, sugar, and 

 cholesterol have been made in all our cases in addition to the 

 above determinations. In our earlier estimations of creatinine, 

 Shaffer's suggestions for the estimation of creatinine in dilute 

 solutions were followed, but recently we have employed Folin's 

 new method which has been found very satisfactory. 



82 (899) 



The significance of the non-protein nitrogen of the blood in 

 experimental uranium nephritis. 



By Herman O. Mosenthal. 



[From the Department of Medicine and the Laboratory of Bio- 

 chemistry, Columbia University.] 



The increase in the non-protein nitrogen content of the blood 

 in the experimental uranium nephritis of dogs may be due to: 



1. Diminished secretory activity of the kidney. This is un- 

 doubtedly the case in those instances of severe nephritis in which 

 the urinary nitrogen is diminished. 



2. Increased protein catabolism. In poisonings of less intensity 

 but sufficient to produce a nephritis of considerable severity as 

 indicated by the albuminuria, there may be an increased amount 

 of nitrogen in the urine as compared to the intake. In these 

 instances the amount of non-protein nitrogen in the blood rises 

 considerably. Such an increase, not being due to nitrogen re- 

 tention on the part of the kidney, may be ascribed to an increased 

 protein catabolism. 



3. Inspissation of the blood. A polyuria, resulting in loss of 

 water to the animal in this form of nephritis, may cause an ap- 

 parent rise in the non-protein nitrogen of the blood. 



4. The chemical combination in which the non-protein nitrogen 

 of the blood exists. Animals with a certain degree of uranium 

 nephritis are capable of putting out extremely high amounts of 

 nitrogen in the urine. (A dog of 15 kilos daily eliminated 23 gm. 



