Difference in Response to Uranium Nitrate. 159 



regime. The criticism which may be made of experiments with 

 short chain aldehydes, ketones, ketoacids, etc., in dogs prepared 

 by fasting and phlorhizin alone are not applicable to the results 

 obtained with animals which have been subjected to cold until 

 all glycogen has been exhausted ; nor is it necessarily implied that 

 alanine, aspartic acid, lactates, propionates, and many other bland 

 substances which have been studied might not yield entirely 

 satisfactory results even in the presence of a residue of glycogen. 



99 (9i6) 



On the difference in the response of animals of different ages to a 

 constant quantity of uranium nitrate. 1 



By Wm. deB. MacNider. 



[From the Laboratory 0} Pharmacology, University of North Carolina.] 



The following report is based upon the difference in the response 

 of forty-eight animals of different ages to a constant quantity of 

 uranium nitrate. 



Dogs have been employed in all of the experiments. The 

 animals have varied in age from puppies of four months old, to 

 animals of extreme old age, one of the animals having reached the 

 age of twenty years. 



All of the animals have received uranium nitrate in the dose of 

 6.7 mgs. per kilogram on two successive days. The uranium was 

 given subcutaneously. 



The animals were fed on raw meat and bread. 



In a recent publication 2 it has been shown that when a constant 

 quantity of uranium nitrate is given to young and full grown 

 animals, that the age of the animal influences the total output of 

 urine and also the composition of the urine. The total output of 

 urine in a twenty-four hour period was greater in the adult animals. 

 The percentage of glucose in the urine (Benedict determination) 

 was greater in the adult animals than in the puppies. 



In the urine of the puppies acetone was either absent or present 



1 Aided by a grant from the fund for Scientific Research of the American Medical 

 Association. 



3 MacNider, Jour, of Pharm. and Exper. Ther., IV, 6, 1913. 



