474 Influence of Inanition on Metabolism. 



ENERGY. 



In common with all living organisms, fasting man is constantly producing 

 and giving off heat as a result of katabolism. The amounts of heat produced, 

 the source of the energy, the factors influencing heat production, and all allied 

 topics have an unusual interest when studied with fasting man. 



Likhachev 161 experimented on a man fasting for 24 hours in the Pashutin 

 respiration apparatus modified so as to permit the direct measurements of heat. 



It has been necessary in all other inanition experiments to compute the 

 energy transformations from the data for the total katabolism, and since there 

 was no means of ascertaining whether the katabolized material other than 

 protein consisted of fat or glycogen, it was assumed that it was all fat. Hence, 

 the computations of the energy transformations were subject to all the errors 

 incidental to the determination of the amounts of katabolized protein and fat. 

 The measure of the protein katabolism was essentially that used in the present 

 day, but we have seen from the foregoing discussions that the amounts of fat 

 katabolized as computed from the total carbon output and the carbon of pro- 

 tein are materially different from those determined by the present method, in 

 which the direct measurement of the oxygen consumption permits an apportion- 

 ment of the total katabolism as protein, fat, and glycogen. The oxidation of 

 one gram of carbon in the form of glycogen gives rise to much less heat than 

 the oxidation of one gram of carbon in the form of fat, and hence the energy 

 transformations computed on the assumption that only fat and protein were 

 burned in the body must of necessity be erroneous. 



In the experiments here reported, not only were the total amounts of 

 katabolized protein, fat, and glycogen computed, but the type of apparatus also 

 permitted direct determinations of the amounts of heat eliminated. Since 

 there were varying amounts of heat residual in the body at the end of the 

 different days of the different experiments, corrections were applied to the 

 heat elimination to obtain the actual heat production. (See discussion, p. 46.) 



For the purpose of comparing the estimated energy derived from material 

 oxidized in the body, the heat production rather than the heat elimination 

 must be used. Heat elimination will first be considered in the following 

 discussion, and then the heat production. Aside from the kinetic energy 

 leaving the body there are considerable amounts of potential energy excreted 

 in the unoxidized material of the urine. For this reason, a particular section 

 of the report is reserved for the discussion of the energy of the urine. 



HEAT ELIMINATION. 



The calorimetric features of the respiration calorimeter were devised for 

 the special purpose of measuring directly the heat eliminated by man. 



The tests of the accuracy of the apparatus have been numerous and severe, 

 and in practically every instance, the results obtained have been all that could 



181 Dissertation, Russian (1893), St. Petersburg. 



