ELIMINATION OF CAFFEIN IN NEPHRECTOMIZED RABBITS. 11 



days after double nephrectomy. The feces were in almost all cases 

 well formed and hard, but in a few animals they were soft. Diarrhea 

 after double nephrectomy was seldom observed. Caffein was admin- 

 istered by subcutaneous injection. The plan of the experiment, as 

 well as the method for the determination of caffein, was the same as 

 that given in Bureau of Chemistry Bulletin 157. No important 

 deviations were made, except that in most experiments the contents 

 of the various portions of the gastrointestinal canal of one rabbit 

 were examined instead of combining those of several subjects. 



ELIMINATION OF CAFFEIN DURING THE FIRST 22 HOURS (SERIES I, II, AND III). 



SERIES I : Rabbits 730 and 731. Gray; weight, 2,370 and 2,010 grams, respectively; 

 diet, oats, for several months. 



January 12: Nephrectomized at 5 p. m. 



January 13: Both subjects were alive and seemingly well, not having shown any 

 symptoms in the interim. They were chloroformed 22 hours after double nephrectomy. 

 The combined bile amounted to about 10 cc, and did not contain any caffein. The 

 combined stomach contents weighed about 150 grams and contained 1.16 per cent of 

 the caffein administered. The feces and intestinal contents of rabbit No. 730, which 

 was a pregnant female almost ready to deliver, contained 8.50 per cent of the caffein 

 administered. Of the quantity of caffein injected, 1.23 per cent was recovered from 

 the uterus and its contents, making a total of 10.89 per cent caffein recovered from 

 all sources following the subcutaneous injection of caffein (100 mg per kilo) 22 hours 

 previously. 



The elimination of caflfein in this experiment indicates a marked 

 compensation of the excretory function of the gut, since the amount 

 was several times as large as in normal rabbits fed on carrots and 

 nearly twice the amount of that in rabbits which received oats. 

 This may be seen on comparing the above data with those hi the 

 following experiment taken from Bulletin No. 157, page 17. 



Caffein recovered from normal rabbits killed 24 hours after injecting 150 mg per kilo. 



The difference in the elimination by the gut between the normal and 

 nephrectomized rabbits is therefore marked. While in the former 

 the maximum amount of caffein found was only 3.5 per cent, the 

 amount present in the gut of the nephrectomized rabbit was 8.5 

 per cent, or nearly two and one-half times as much as in the normal 

 rabbits. The quantity of caft'ein in the stomach was practically 

 the same in nephrectomized as in normal rabbits. This seems to 



