14 Journal of the Mitchell Society [May 



in the general blood pressure rise and in the vascular response 

 of the kidnej. 



4. In certain of these animals the flow of urine is increased 

 bj these diuretics while in other animals the urine flow is unin- 

 fluenced. 



5. Histologically the vascular pathology of the kidney is 

 similar in those animals which show a diuretic effect and in 

 those animals which remain anuric. 



6. Those animals which remain anuric show a physiological 

 vascular response on the part of the kidney vessels similar to 

 the resj)onse which is obtained in the diuretic animals. The 

 physiological and the pathological reaction of the kidney ves- 

 sels in the anuric and in the diuretic animals are, there- 

 fore, similar. 



7. The two groups of animals differ, however, in the degree 

 of involvement of the epithelial element of the kidney. The 

 anuric animals show an epithelial involvement which is severe 

 and which results anatomically in an encroachment upon, or 

 occlusion of, the lumen of the tubules, while in the diuretic 

 animals the epithelial changes are less marked and are insuffi- 

 cient to j)roduce a mechanical obstruction of the tubular lumen. 



8. The pathology of the kidney of those animals with an 

 early uranium nephritis which were examined prior to the use 

 of an anesthetic showed a vascular pathology which in general 

 was similar to the vascular pathology of the anuric, practically 

 anuric and diuretic animals. The tubular epithelium of these 

 animals which were polyuric, showed but slight changes, and in 

 their epithelial reaction the kidneys of these animals were more 

 nearly comparable to the kidneys of the diuretic animals than 

 they were to the kidneys of the anuric animals. 



The physiological and anatomical observations which have 

 been made in this investigation indicate that in a uranium 

 nephritis the epithelial changes are more responsible for a re- 

 duction in the output of urine or an anuria than are the vascu- 

 lar changes. The way in which these changes influence the 

 output of urine will furnish the basis for a subsequent investi- 

 gation. 



