METABOLISM 

 METABOLISM IN FASTING 



6lQ 



The fasting treatment 1 is also being used with success in cases of diabetes 

 mellitus and in the treatment of obesity. 2 



In order to determine experimentally how the fasting metabolism differs from 

 normal metabolism proceed as follows : Ingest an ordinary mixed diet and col- 

 lect your urine (see page 598) for a day. Measure the volume and analyze the 

 sample for total nitrogen, ammonia, creatine, sodium chloride, total phosphates 

 and acidity 3 (for methods see Chapter XXVII). For the next few days (three to 

 seven as desired) ingest nothing but water and collect the urine accurately and 

 analyze for the constituents enumerated above. Tabulate your results and 

 compare them with those given hi the table above. 



30. Synthesis of Hippuric Acid in Human Body. -Hippuric Acid is 

 present in human urine in small amount, about 0.7 gram being excreted 

 per day. The urine of herbivorous animals contains much larger quan- 

 tities. This acid is formed in the animal body, by synthesis from ben- 

 zoic acid and glycocoll which takes place in the kidneys and elsewhere. 4 



Experiment. Ingest 2 grams of sodium benzoate or ammonium benzoate 

 before retiring at night. Collect the first fraction of urine voided the next morn- 

 ing. The benzoate has been synthesized with glycocoll to form hippuric acid. 

 The urine will therefore be found to contain much more of this acid than is nor- 

 mally present. Isolate the hippuric acid by one of the following methods : 



(a) First Method. Render the urine alkaline with milk of lime, boil for a few 

 moments and filter while hot. Concentrate the filtrate, over a burner, to a small 

 volume. Cool the solution, acidify it strongly with concentrated hydrochloric 

 acid and stand it in a cool place for 24 hours. Filter off the crystals of hippuric acid 



1 Allen: Amer. Jour. Med. Sci., 150, 480, 1915. 



2 Folin and Denis: Jour. BioL Chem., 21, 183, 1915. 



3 A more accurate experiment may be carried out by ingesting a uniform diet of known 

 composition (see page 602) for a few days before the fast. 



4 Kingsbury and Bell: Jour. BioL Chem., 21, 297, 1915. 



