14 



CAFFEIN IN NEPHRECTOMIZED RABBITS. 



It will be noticed that the rate of elimination was especially marked 

 in the intestines, the amounts of caffein varying considerably, but it 

 was not quite in proportion to the time which elapsed between the 

 administration of the caffein and the death of the animal. This is 

 far in excess of the relative amounts recovered from the urine of rab- 

 bits at a corresponding period of time after the injection of caffein. 

 As stated previously (Bulletin 157), from 3 to 4 per cent of the caffein 

 introduced was found in the urine three and three and a half hours 

 after the administration of the drug. 



As the striking results obtained in Series V and in rabbit No. 738 

 might have been due to abnormal conditions, the rabbits in all of 

 these cases having lived only a few hours after nephrectomy, it 

 seemed desirable to repeat the experiments on other rabbits, employ- 

 ing the usual route for the removal of the kidney. Caffein was in- 

 jected subcutaneously shortly after the kidneys were removed. 



ELIMINATION OP CAFFEIN IN 4 HOURS (SERIES VI). 



Double nephrectomy was performed by lumbar incision under 

 ether anaesthesia. The average time of the operations, which were 

 practically bloodless, was 15 minutes. The characteristic caffein 

 symptoms, such as increased sensitiveness, avoidance of light, and 

 extreme restlessness, were marked in each of the subjects, although 

 to a somewhat less degree in rabbit No. 757. The general condi- 

 tion of the rabbits remained favorable up to the end, there being no 

 manifestation of weakness. 



SERIES VI. Caffein elimination in nephrectomized rabbits after subcutaneous injection 



of 200 mg per kilo. 



The results obtained in this series were practically the same as 

 those in Series IV and V, the absolute and relative amounts of 

 caffein eliminated being quite large. The elimination by the intes- 

 tinal epithelium in the experiments of this series is interesting, as a 

 decided difference in the rate of elimination was observed in 

 rabbit No. 759, which amounted to about 1 to 2.5 per cent more than 

 in the other two rabbits. 



The experiments of Series VII were made to test the suggestion 

 that elimination is probably more rapid during the first few hours 



