TOXICITY OF CAFFEIN IN NEPHRECTOMIZED RABBITS. 29 



Since the duration of life in this series of experiments was not less 

 than 20 hours, the amounts of caffein injected, about 110 mg per 

 kilo, can not be regarded as fatal. That absorption was good is 

 indicated by the symptoms manifested by rabbit No. 794, as the 

 effects of caffein could be noticed in less than 2 hours after its admin- 

 istration. The condition of rabbit No. 796 was probably accidental 

 and not due to caffein nor to removal of the kidney, as paralysis 

 occurs sometimes spontaneously. On the other hand, those symp- 

 toms had never been observed so soon after nephrectomy or after 

 small doses of caffein. Moreover, since no symptoms of excitement 

 were present, this dose of caffein can not be regarded as toxic. 



EFFECT OF OPERATION ON TOXICITY (SERIES VII). 



As a further test of the resistance of the rabbit to caffein under this 

 condition, it seemed advisable to control the operative procedure 

 involved in the removal of the kidney, for it is possible that the 

 effect of exposing the kidney and the anaesthesia may modify the 

 toxicity of caffein independently of the removal of the organ. This 

 was carried out in the following experiments on 6 rabbits, Nos. 812, 

 813, 814, 824, 825, and 826. One, No. 813 (165 mg per kilo), showed 

 symptoms of severe intoxication in one and one-half hours after it 

 received caffein and died during the night; No. 812 (200 mg per 

 kilo) lived one and one-half hours; No. 824 (146 mg per kilo) was 

 found paralyzed the next day; No. 814 (150 mg per kilo) showed 

 mild symptoms of caffein intoxication and survived. The other two 

 showed no effect of caffein. The operation, aside from the removal 

 of the kidney, therefore increased the toxicity of caffein. This is 

 shown in the following protocols to the experiment: 



Rabbit 812. White female; weight, 1,950 grams. 



tyay 20: 3.05 p. m., kidney exposed by lumbar incision but not removed; 4.15 

 p. m., condition good, 15 cc of 2 per cent caffein injected subcutaneously; 5.45 p. m., 

 rabbit dead, stiff and warm. 



Rabbit 813. Black male; weight, 1,785 grams. 



May 20: 2.45 p. m., kidney exposed by lumbar incision but not removed, wound 

 closed; 4.20 p. m., 15 cc of 2 per cent caffein injected subcutareously; 5.45 p. m., 

 reflexes very much increased and rabb?t avoided light; symptoms of severe caffein 

 intoxication present. 



May 21: 9 a. m., found dead. 



Rabbit 814. Black male; weight, 2,080 grams. 



May 20: 3.35 p. m., kidneys exposed by lumbar incision and wound closed, but 

 kidney not removed; 4.17 p. m., 16 cc of 2 per cent caffein subcutaneously injected; 

 5.45 p. m., reflexes increased, but not very marked. 



May 21: 9 a. m., alive, in good condition. 



May 22: 11 a. m., weight, 1,935 grams, appetite good. 



May 23: Alive, condition good. 



Rabbit 825. Belgian hare, female; weight, 1,290 grama. 



