PROTEIN METABOLISM IN STARVATION. 837 



fifth day of starvation from 1850 to 1600 calories, or from 32.4 to 30 per 

 kilo, and it remained nearly unchanged, if referred to the unit of body 

 weight. 1 In man the average daily energy consumption in starvation 

 amounts to about 30-32 calories per kilo. 



The extent of the metabolism of proteins, or the elimination of nitrogen 

 by the urine, which is a measure of the same, diminishes as the weight 

 of the body diminishes. This decrease is not regular or the same during 

 the entire period of starvation, and the extent depends, as the experi- 

 ments made upon carnivora have shown, upon several circumstances. 

 During the first few days of starvation the excretion of nitrogen is greatest, 

 and the richer the body is in protein, due to the food previously taken, 

 the greater is the protein catabolism or the nitrogen elimination, accord- 

 ing to VOIT. The nitrogen elimination diminishes the more rapidly 

 that is, the curve of the decrease is more sudden the richer in proteins 

 the food was which was taken before starvation. This condition is 

 apparent from the following table of data of three different starvation 

 experiments made by VoiT 2 on the same dog. This dog received 2500 

 grams of meat daily before the first series of experiments, 1500 grams of 

 meat daily before the second series, and a mixed diet relatively poor in 

 nitrogen before the third series. 



Day of Starvation. Grams of Urea Eliminated^ Twenty-four g Hou. 



First 60.1 26.5 . 13.8 



Second 24.9 18.6 11.5 



Third 19.1 15.7 10.2 



Fourth 17.3 14.9 12.2 



Fifth 12.3 14.8 12.1 



Sixth 13.3 12.8 12.6 



Seventh 12.5 12.9 11.3 



Eighth 10.1 12.1 10.7 



In man and also in animals sometimes a rise in the nitrogen excretion 

 is observed about the second or third starvation day, which is then fol- 

 lowed by a regular diminution. This rise is explained by PRAUSNITZ, 

 TIGERSTEDT, LANDERGREN, 3 as follows: At the commencement of star- 

 vation the protein metabolism is reduced by the glycogeri still present 

 in the body. After the consumption of the glycogen, which takes place 

 in great part during the first days of starvation, the destruction of pro- 

 teins increases as the glycogen action decreases, and then decreases again 

 when the body has become poorer in available proteins. 



Other conditions, such as varying quantities of fat in the body, have 

 an influence on the rapidity with which the nitrogen is eliminated during 



1 See also Tigerstedt and collaborators in Skand. Arch. f. Physiol., 7. 



2 See Hermann's Handbuch. 6, Thl. 1, 89. 



3 Prausnitz, Zeitschr. f. Biologic, 29; Tigerstedt and collaborators, 1. c.; Landergren, 

 Undersokningar ofver menniskans agghviteomsattning, Inaug.-Diss. Stockholm, 

 1902. 



