Creatinine and Creatine. 



391 



The data, therefore, furnish evidence as to the excretion of creatinine during 

 the different periods of the day. Such determinations as are available have been 

 placed in table 204. A comparison of the total amount in 24 hours as recorded 

 in this table and the corresponding amount as recorded in table 203 shows 

 slight discrepancies on the different days. The record in table 203 is that 

 determined on the daily composite sample, while that in table 204 is the sum of 

 the amounts of preformed creatinine for the four periods of each day. When 

 the large volumes of urine are taken into consideration the agreement is as 

 satisfactory as could well be expected. The table shows the actual amount of 

 preformed creatinine excreted in the periods from 7 a. m. to 1 p. m., from 1 

 p. m. to 7 p. m., and the total for the first 12 hours of the day, the amount for 

 the night being given in one column as was the case in table 198, showing the 

 distribution of nitrogen by periods. The unequal division of the night into a 

 4-hour and an 8-hour period makes this presentation of the results more 

 satisfactory. 



Table 204. Preformed creatinine by periods eliminated in urine in metabolism 



experiments Nos. 75 and 16. 



Exper- 

 iment 

 num- 

 ber. 



Subject and date. 



7 a.m. 



to 

 1 p.m. 



1 p.m. 

 to 



7 p.m. 



Total for 

 first 12 hours. 



Am'nt. 



Propor- 

 tion 



of total 

 for 24 

 hours. 



Total for 

 last 12 hours. 



Am'nt. 



Propor- 

 tion 



of total 

 for 24 

 hours. 



Total 



amount 



in 24 



hours. 



75.. 



76. 



1905. 

 S.A.B.: 



Mar. 4- 5 



Mar. 5- 6 



Mar. 6- 7 



Mar. 7- 8, 

 Mar. 8- 9 



Mar. 9-10 



Mar. 10-11 



S.A.B.: 



Mar. 11-12, 



Mar. 12-13. 



Mar. 13-14, 



Orams. 



0.340 

 .313 

 .236 

 .243 

 .169 

 .157 

 .148 



.263 

 .365 

 .348 



Orams. 



0.330 

 .256 

 .222 

 .212 



.148 

 .158 

 .175 



.302 

 .304 

 .350 



Per ct. 



45.4 

 45.6 

 47.5 

 41.7 

 51.2 

 51.5 

 55.6 



49.3 



45.7 

 48.1 



Grams. 



1.228 



1.045 



.873 



.780 

 .649 

 .650 



.728 



1.114 

 1.233 

 1.346 



Considering first the apportionment of the total preformed creatinine 

 excretion between the day and the night periods, the figures show that during 

 the day the per cent may be as low as 44.4 of the total and as high as 58.3. 

 The percentage excreted during the day has a distinct tendency to become 

 lower as the fast progresses. Aside from the 58.3 per cent on the fourth day of 

 the fast, the decrease is very constant. On the ingestion of food, the excretion 

 of performed creatinine during the first 12 hours of the day averages about 52 

 per cent. 



