96 



Scientific Proceedings (33). 



46 (384) 



An experimental study of the influence of kidney extracts and 

 of the serum of animals with renal lesions upon 

 the blood pressure. 



By RICHARD M. PEARCE, M.D. 



[^From the Carnegie Laboratory of the University and Be/levue 

 Hospital Medical College, New York City.'\ 



1. Extracts of the rabbit's kidney injected into the rabbit cause 

 a slight increase in blood pressure which is barely more than that 

 due to the mechanical effect of the injection. 



2. Extracts of the dog's kidney injected into the dog cause a 

 decided fall in pressure ; an equal fall may be caused by the dog's 

 urine. A series of control experiments indicates that the fall caused 

 by the kidney extract may be due to the urinary salts which it 

 contains. 



3. Extracts of cat's kidney cause a rise in pressure ; as the cat's' 

 urine causes a fall, this rise in pressure indicates the possibility of 

 a kidney extract containing a pressor substance which cannot be 

 influenced by the depressor substance of the urine. 



4. Rabbit's kidney which in the rabbit produces a slight rise 

 when injected into the dog causes a drop comparable to that caused 

 by the dog's kidney itself. Similarly the dog's kidney, which in- 

 jected into the dog causes a drop, produces in the rabbit a rise 

 analogous to that produced by rabbit's kidney. It is evident there- 

 fore that these pressor and depressor substances of the kidneys in 

 question do not have a constant effect on all animals as do the 

 extracts of the adrenal gland. 



5. Extracts of kidneys which are the seat of various forms of 

 nephritis cause the same effect as extracts of normal kidneys. 



6. The serum of dogs with considerable reduction of kidney 

 substance causes a slight fall in pressure ; the serum of dogs with 

 spontaneous nephritis gives divergent results, as does also the 

 serum of rabbits with various forms of acute nephritis. The serum 

 of dogs with chromate nephritis causes a slight rise, while that of 

 dogs with uranium nephritis produces a sharp and decided fall in 

 pressure. Although there is no uniformity in these results, their 



