390 Influence of Inanition on Metabolism. 



Somewhat similar results were obtained by Klercker. 68 



While in some ways it is difficult to harmonize the results of Folin and 

 Klercker with those here reported, both sets of experiments emphasize the fact 

 that it is difficult at times for the body to convert creatine to creatinine. 



It would appear, then, that if the body possesses a ferment which can 

 dehydrate creatine to creatinine, the secretion or possibly the activity of this 

 ferment is markedly decreased by fasting. 



In this connection, it is important to observe the rapidity with which the 

 body recovers its power to convert creatine to creatinine after the ingestion of 

 food. Thus, in experiment No. 76, the excretion of creatine which on the day 

 previous (seventh fasting day) was 0.488 gram was reduced to 0.274 gram, 

 although this day differs in no wise from the day preceding except in that the 

 following amounts of food were eaten: 651 grams modified milk, 123 grams 

 apple, 313 grams orange juice, 178 grams shredded wheat, and 10 grams gluten 

 crackers. 



Unfortunately, the determinations of total creatinine on the two following 

 days of experiment No. 76 could not be made, but from the determinations of 

 creatinine, made before heating with acid, the deduction may be made that 

 the normal elimination of creatinine had been reached on the second day of the 

 experiment, and that in all probability the amount of creatine excreted on this 

 day was very small. In fact, 3 days later, namely, March 14-15, the amount of 

 creatine was again determined and found to be but 0.073 gram. The power to 

 convert creatine was regained in an even more striking manner in nitrogen 

 metabolism experiment No. 2. The creatine excretion (as creatinine) of April 

 11-12 was 0.538 gram. On the next day with food (April 12-13) it was only 

 0.043 gram. This practical disappearance of creatine from the urine was 

 incidental to the ingestion of food on the first day that the subject was out of 

 the respiration chamber and subsisting on a creatine-free diet of his own selec- 

 tion. The kinds and amounts of food eaten this day are given in table 176. 



While in all cases, the creatine practically disappeared upon the ingestion 

 of food, there was no marked increase in the total creatinine from day to day, 

 which indicates that the creatine had simply been converted to creatinine and 

 excreted as such. In all of the food experiments following fast, care was taken 

 to avoid foods containing creatine and creatinine, though throughout the nitro- 

 gen metabolism experiments the diet was practically creatine-free, as the sub- 

 ject ate meat on only one or two occasions. On all days when samples were 

 taken for creatinine determinations no meat had been taken for 24 hours. 



Excretion of creatinine by periods. In experiments Nos. 75 and 76 the 

 determinations of preformed creatinine, i. e., creatinine determined before 

 heating with acid, were made on the samples collected during each period. 



^Zeit. f. gesammte Biochemie (1906), 8, p. 59. 



