26 CAFFEIN IN NEPHRECTOMIZED RABBITS. 



sions. These results do not support, therefore, the view expressed 

 above, that substances antagonistic to caffein may form after 

 nephrectomy, for the rapid death of rabbits Nos. 800 and 801 shows a 

 decidedly increased toxicity of caffein when injected after the lapse 

 of a few hours following double nephrectomy. This may be due to 

 more rapid absorption at this time as has been shown for substances 

 other than caffein. Meltzer and Salant 18 observed increased absorp- 

 tion of salt solution from the peritoneal cavity of nephrectomized 

 rabbits. This was also found by Loeb and Fleischer under similar 

 conditions. Such being the case, the diminished resistance to caffein 

 may be expected to continue, and indeed become more marked the 

 longer the interval between double nephrectomy and the administra- 

 tion of caffein, since, as was shown by Archard and Loper, the 

 osmotic pressure of the blood increases steadily after removal of the 

 kidneys. That the toxicity, however, is less under these conditions 

 is shown in rabbits Nos. 815 and 816. The greater resistance as 

 compared with rabbits Nos. 800 and 801 suggests, oh the contrary, 

 the presence of substances which are capable of counteracting the 

 effect of caffein. Additional support is afforded by the following 

 experiments: 



SERIES V,* GROUP A. Caffein administered shortly after operation, under ether 



anesthesia. 



Rabbit 790. Gray female; weight, 1,810 grams. 



April 26: 11.55 p. m., double nephrectomy by lumbar incision; 2.30 p. m., 18.5 cc 

 of 2 per cent warm caffein solution injected subcutaneously in the back; 3.15 p. m., 

 reflexes increased moderately; 5.15 p. m., reflexes much more marked. 



April 27: 11 a. m., paresis of extremities and impaired coordination, dyspnoea, 

 spasms; died at 11.20 a. m. Lived 21 hours after injection of caffein. 



Rabbit 788. Gray female; weight, 1,520 grams. 



April 26: 11.30 a. in., double nephrectomy by lumbar incision; 2.30 p. m., 15.5 cc 

 of 2 per cent warm caffein solution injected subcutaneously in the back; 3.15 and 5.15 

 p. m., reflexes as in the other two rabbits of this series. 



April 27: 11 a. m., reflexes increased, moderate degree of incoordination of posterior 

 extremities, respiration deeper and slower. 



April 28: 2.45 p. m., rabbit alive, standing in cage, looked somewhat sick, depressed, 

 breathing more slowly than normal; 4.30 p. m., still alive. 



April 29: found dead; apparently died in convulsions. Lived more than 2 days. 



Rabbit 789. Gray female; weight, 1,630 grams. 



April 26: 11.30 p. m., bilateral nephrectomy performed by lumbar incision, loss of 

 blood slight (perhaps 1 cc); 2.30 p. m., 16.5 cc of 2 per cent warm solution of caffein 

 injected subcutaneously in the back; 3.15 and 5.15 p. m., reflexes as in rabbit No. 790. 



April 27: 8.45 a. m., rabbit found dead. 



Lived less than 18 hours. 



SERIES V, GROUP B. Caffein administered on day after operation. 



Rabbit 8%0. White and yellow female; weight, 1,885 grains. 

 May 22: 1 p. m., double nephrectomy. 



200 mg. caffein per kilo. 



