Observations on Metabolism. 



129 



68 (406) 



The depressor substance of dog's urine ; its disappearance in 

 experimental acute nephritis. 



By RICHARD M. PEARCE. 



[^Fi'07n the Carnegie Laboratory of the New York University and 

 Bellevue Hospital Medical College^ 



The urine of a normal dog when injected intravenously into 

 another dog in doses of three cubic centimeters causes an immedi- 

 ate fall in blood pressure varying from 25 to 96 mm. of Hg. This 

 effect, constant for normal urine, is not always obtained when the 

 urine from a chromate or uranium nephritis of the third to fifth day 

 is used. It is still obtained, however, in arsenic and cantharidin 

 nephritis of the same periods. This difference suggests that in the 

 tubular lesions of chromate and uranium nephritis, which are 

 characterized by extensive epithelial destruction, some substance 

 normally eliminated is retained while in the glomerular nephritis 

 caused by arsenic and cantharidin poisoning this retention does 

 not occur. The elimination of the depressor substance would ap- 

 pear therefore to be a function of the tubular epithelium. 



In animals with experimental nephritis of the tubular type the 

 disappearance of the depressor substance from the urine is fre- 

 quently associated with a lowering of the blood pressure which 

 would appear to indicate that the retained depressor substance has a 

 definite effect on the general blood pressure. This observation is 

 not based however on blood pressure determinations on the same 

 animal before and after the development of nephritis but by con- 

 trasting the pressure in animals with tubular nephritis with that of 

 normal animals and those with glomerular nephritis. 



The nature of the depressor substance has not been determined. 



69 (407) 



Observations on the metabolism of a subject of diabetes. 

 By PHILIP A. SHAFFER. 



\_Fro))i the Laboratory of Pathological Chemistry , Department of 

 Experimental Pathology, Cornell Medical College 

 The subject of the observations was a patient in the service of 

 Dr. Warren Coleman in Bellevue Hospital. Different known 



