SECTION II 

 METABOLISM DURING STARVATION 



IT will tend to simplify our task if we deal first with the results of the 

 experiments which have been made on the metabolic exchanges of animals 

 during starvation, i. e. during a period when the whole energy involved in 

 the maintenance of the movements of respiration and circulation, and' in 

 the maintenance of the body temperature, etc., is derived from the animal's 

 own tissues. It must be remembered that the tissues of an animal comprise 

 two distinct classes. In the first class must be placed the living machinery 

 of the body, generally composed of proteins or their near allies. In the 

 second class are the fatty tissues of the body, which form no part of the 

 ordinary machinery, but function simply as a storehouse of material which 

 can be utilised for the production of energy. In addition to the store of fat 

 there is, in a well-fed animal, a certain reserve of carbohydrate in the form 

 of glycogen, deposited in the liver and the muscles. This store of glycogen 

 is drawn upon to a large extent at the beginning of a period of starvation. 

 The total amount of glycogen present at any time is generally so small in 

 comparison with the fat of the body that it cannot provide the energy 

 necessary for the maintenance of life during prolonged inanition, although 

 it plays an important part during the first one or two days of a period of 

 starvation. 



Contrary to general belief, the condition of an animal which is completely 

 deprived of food is not a painful one. For this statement we have not only 

 such evidence as can be derived from inspection of animals placed in this 

 condition, but also evidence derived from men who have voluntarily or 

 involuntarily been deprived of food for considerable periods. Especially 

 instructive in this connection are the cases of the so-called professional 

 * fasting men,' two of whom, Succi and Cetti, have been subjected to com- 

 plete metabolic investigation during the period of their starvation. During 

 the first day or two there is a craving for food at meal-times. This how- 

 ever passes oiY. ;m<l during the later portions of the experiment even the 

 desire I'm- lon<l mav IK- entirelv absent. As might be expected, the restric- 

 tion of food is followed by a diminution in tin- amount of water required 

 by tin- animal. Tin- essential characteristic of the state of inanition is an 

 ever-increasin- weakness, accompanied by a strong disinclination to under- 

 take any mental or physical exertion whatsoever. The animal passes its time 

 in a state of sleep 01 semi-stupor. In the case of Succi, who fasted for thirty 

 days, considerable muscular exertion was undertaken on the twelfth and 

 on the twenty -third day of starvation without any appreciable ill-effects. 

 A strong effort of the will must have been necessary in his case to overcome 

 the automatic instinct to preservation of life by the utmost economy in the 

 expenditure of em-riiy. Hie pulse rate and the body temperature remain 



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