ELIMINATION OF CAFFEIN IN NEPHRECTOMIZED RABBITS. 13 



SERIES IV. Three nephrectomized rabbits which received 200 mg caffein per kilo. 



The relative and absolute amounts of caffein eliminated in this ex- 

 periment were much greater than in those already considered. Espe- 

 cially noteworthy is the rate of elimination hi rabbit No. 738, which 

 excreted in seven hours nearly one-sixth of the caffein injected. This, 

 it will be observed, is greater than the relative amounts excreted by 

 the kidney and gastrointestinal canal of the rabbits previously exam- 

 ined in this laboratory (see Bulletin 157) or of those of the present 

 investigation. The difference in the doses employed might have been 

 responsible for the greater output of caffein, but, as will be seen 

 later, this was not the case. Abnormality or accident might also be 

 thought of as factors in this connection. Before deciding, however, 

 that such was the case the necessity of obtaining additional data on 

 the rate of elimination of caffein at various intervals after its admin- 

 istration in nephrectomized rabbits presented itself, and the experi- 

 ments of the following series were undertaken with this object in 

 view. 



ELIMINATION OF CAFFEIN IN FROM 1 TO 3 HOURS (SERIES V). 



The kidneys were in all cases removed by the abdominal route 

 under ether anaesthesia. The operations were practically bloodless. 

 The recovery from the operation seemed to be very slow, the rabbits 

 remaining in a greatly weakened condition up to the end. After the 

 administration of caffein the rabbits became hypersensitive. 



SERIES V. Caffein elimination in nephrectomized rabbits after subcutaneous injection of 



150 mg per kilo. 



