PART A 



ENDOGENOUS CATABOLISM, OR NORMAL 

 DETERIORATION OF LIVING MATTER 



(a) ENDOGENOUS CATABOLISM AND AUTOLYSIS 



As all living cells will die if kept without food for a 

 varying number of days (except when in a dry state), 

 it must be assumed that deteriorating changes in living 

 cells take place continuously, and can be counteracted 

 only by assimilation of food. These changes will 

 ultimately cause death of the cell if continued for too 

 long a time. Bacteria are no exception to this rule as 

 will be shown in the chapter on Death by Starvation 

 (p. 377). 



As defined by Folin (1905), this gradual and constant 

 decomposition of living matter may be called endogenous 

 catabolism. All measurements are limited to protein 

 changes, but other compounds may undergo similar 

 changes. Endogenous catabolism has been studied for 

 more than one hundred years with man and animals. 

 It is usually measured by the quantity of nitrogenous 

 matter excreted during starvation or with protein-free 

 diet. The quantity of nitrogen excreted by a starving 

 man seems to vary considerably, but the average is 

 about 6 to 10 gm. of nitrogen per person per day. This 

 means about 80 mg. per kg. of body weight, or, estimating 

 on 10 kg. of protein per average person, it amounts to 

 about 1 gm. of nitrogen for each kg. of dry protein, or 

 to 0.6% of the protein nitrogen. 



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