Excretion of Creatine in Carbohydrate Starvation. 219 



creatinine in the urine was again very constant for the three days, lying 

 between 2 and 2-3 grm. On the first and second days the apparent creatine 

 was 0'12 grm., and on the third day it was 0"16, while no true creatine was 

 excreted. The apparent creatinine was not so low as in Experiments I and II, 

 but its difference from the true creatinine was quite definite enough to be 

 measured on the colorimeter. 



Discussion of Results. 



These three experiments show that the removal of carbohydrate from the 

 diet causes an excretion of aceto-acetic acid in sufficient amount to cause an 

 error in the estimation of creatinine, so that the results are too low and 

 creatine is apparently excreted. 



Cathcart(5), Benedict (2), Mendel and Eose (19) state that creatine occurs 

 in the urine under somewhat similar conditions to those under which we have 

 worked. The amounts of creatine they obtained were about the same as 

 those apparently obtained by us, before we removed the aceto-acetic acid, e.g. 

 the largest amount that Cathcart (5) found on a fat diet was 0"38 grm., which 

 is slightly more than the apparent creatine we found on the third day of 

 Experiment II. 



Cathcart remarks that the creatinine excretion diminishes to a certain 

 extent, as the result of a fat diet. We have found that it remains constant 

 throughout, and in the case of G. G. agreed very closely with the amount of 

 creatinine excreted 15 months before on a pure fat and carbohydrate diet (10). 

 However, the error caused by the presence of aceto-acetic acid in the urine 

 results in less creatinine being found than is actually present. 



Our experiments extended over about the same time as those of Cathcart, 

 but there was a slight difference, viz., that we had no preliminary starvation 

 day. However in Experiment I the condition of semi-starvation was really 

 very similar to that of one day's complete starvation, as only half a pint of 

 cream was taken and the calorie value was 1060. 



We have also published a case of carbohydrate starvation (10) lasting for 

 10 days in which the diet had a calorie value of only 1969 per diem. No 

 creatine was excreted at any time, and the creatinine excretion remained 

 constant throughout. 



From these results we draw the conclusion that mere carbohydrate starva- 

 tion itself does not cause an excretion of creatine in the urine. 



Naturally, no conclusion can be drawn from these experiments as to whether 

 creatine is excreted during prolonged periods of total starvation, but we 

 maintain that in all those many physiological and pathological conditions in 

 which acetone bodies are excreted in the urine, the estimations of creatinine 



