METABOLISM D URING INANITION. 887 



METABOLISM DURING INANITION. 



The problems of metabolism naturally subdivide themselves into 

 those which concern the fate of the foodstuffs after they are absorbed 

 and before they reach the tissues, and those which concern the fate 

 of the stuffs which form the tissues, or which undergo changes within 

 and by the agency of the tissues. The simplest condition of meta- 

 bolism is therefore obtained when food is altogether withheld, as under 

 these circumstances we have only to determine the changes which 

 occur in the bodystuffs. On this account a very large amount of 

 attention has been paid, both recently and previously, to the changes 

 which occur in the tissues, as evidenced by the excreta during inanition 

 in animals and man. 



There is one main fact which comes out in all experiments on 

 inanition, namely, that in spite of the withholding of food, all the 

 excretions continue, not certainly to their normal amount, but at least 

 to a considerable extent. This is even the case with the faeces 

 which, in the absence of food, might be expected not to be formed. 

 But, as a matter of fact, it is found that, during starvation, animals 

 pass, if not every day, at least every two or three days, a fairly regular 

 amount. This is composed of mucus and of inspissated digestive juices, 

 a good deal altered in their composition, together with epithelial cells 

 and other debris. Urine is also regularly passed during a period of 

 inanition. The secretion of the skin is given off; carbon dioxide and 

 water continue to be exhaled from the lungs ; and in consequence of all 

 these losses from the body the animal gradually loses in weight. 

 The greatest proportionate amount lost is always during the first day 

 of a fasting period. This is owing to the fact that the products of 

 metabolism of the proteid food previously absorbed and that still within 

 the alimentary canal are then got rid of. But after the first day or two 

 it is found that the loss in weight is pretty definite, and nearly regular 

 from day to day, and that fairly regular, or at least only gradually 

 decreasing, amounts of the various excreta are lost daily. 1 Thus Voit, 2 

 experimenting upon a cat, found that about 4 to 5 grms. of urea were 

 passed each day, representing a loss of tissue of from 25 to 30 grms., 

 and this with great regularity until the twelfth day, when there was a 

 marked rise in the amount of urea eliminated. And similar results 

 have been obtained both with other animals and men in a condition 

 of inanition. 



The time at which this regular daily loss of nitrogen begins, depends 

 upon the previous condition of nourishment. Thus, in a dog experi- 

 mented upon by Voit, three series of experiments were made, each 

 extending over eight days of total deprivation of food. The animal had 

 received before the first series, 2500 grms. of flesh daily ; before the 

 second, 1500 grrns. ; and before the third, a mixed diet with relatively 

 little proteid. The results obtained are shown in the table on p. 

 888. It will be seen that the regular loss begins at once in the third 

 series, but not until the fifth day in the first series, in which the animal 

 received most proteid during the previous period. The actual amount of 

 proteid excreted per diem and per kilo, bodyweight was found by Voit 



1 The amount of fat metabolised in the dog was found by Pettenkofer and Voit to be 

 less during the first days than during the subsequent period. 



2 Hermann's " Handbuch," Bd. vi. 



