December 21, 1917] 



SCIENCE 



619 



The object of the present investigation was 

 to determine if catalase is decreased more 

 quickly and more extensively during chloro- 

 form anesthesia than during ether anesthesia 

 parallel with the greater decrease in oxida- 

 tion and the quicker and more powerful ac- 

 tion of chloroform. Cats were used in the 

 experiments. The anesthetics were admin- 

 istered by bubbling air through ether or chloro- 

 form in a bottle which was connected by a 

 rubber tube to a cone adjusted to the snout of 

 the animal. The catalase content of the blood, 

 taken from the external jugular vein, was de- 

 termined before the administration of the an- 

 esthetic and at intervals of 15 minutes during 

 the administration. The determinations were 

 made by adding 0.5 e.c. of blood to 250 c.c. of 

 hydrogen peroxide in a bottle at 22° C. and 

 as the oxygen gas was liberated it was con- 

 ducted through a rubber tube to an inverted 

 graduated cylinder previously filled with water. 

 After the volxmie of gas thus collected in ten 

 minutes had been reduced to standard atmos- 

 pheric pressure, after resulting volume was 

 taken as a measure of the amount of catalase 

 in the 0.5 c.c. of blood. The bottles were 

 shaken in a shaking machine during the de- 

 terminations at a rate of about 180 double 

 shakes per minute. 



The average amount of oxygen liberated by 

 the blood of three cats previous to the admin- 

 istration of ether was 812 c.c; that liberated 

 after the animals had been under ether for 15 

 minutes was 740 cc. ; that after 30 minutes of 

 ether anesthesia, 630 cc; that after 45 min- 

 utes, 475 cc; that after 60 minutes, 480 cc; 

 after 75 minutes, 400 cc. ; and that after 90 

 minutes, 380 cc. It will be seen that the cata- 

 lase of the blood was gradually decreased dur- 

 ing the 90 minutes of ether anesthesia, as is 

 indicated by the gradual decrease in the 

 amount of oxygen liberated, and that at the 

 end of 90 minutes the catalase had been de- 

 creased by about 54 per cent., as is indicated 

 by the decrease in the amount of oxygen 

 liberated from 812 cc. to 380 cc. 



Similarly determinations were made of the 

 catalase of the blood of cats previous to chlo- 

 roform anesthesia and at intervals of 15 min- 



utes during the anesthesia. The average 

 amount of oxygen liberated by the blood of 

 three cats previous to the administration of 

 chloroform was 900 cc; that liberated after 

 the animals had been under chloroform anes- 

 thesia for 15 minutes was 525 cc. ; that after 

 30 minutes, 325 c.c. ; that after 45 minutes, 

 334 c.c; that after 60 minutes, 320 c.c; after 

 75 minutes, 330 c.c; and that after 90 min- 

 utes, 310 c.c. It will be seen that the chlo- 

 roform produces a very abrupt decrease in the 

 catalase of the blood during the- first fifteen 

 minutes of the administration as is indicated 

 by the decrease in the amount of oxygen liber- 

 ated from 900 to 525 c.c, and that at the end of 

 90 minutes the catalase had been decreased by 

 about 65 per cent., as is indicated by the de- 

 crease in the amount of oxygen liberated from 

 900 to 310 c.c. 



By comparing the decrease in the catalase 

 produced by ether and by chloroform it will be 

 seen that the ether produced a gradual de- 

 crease as is indicated by the gradual decrease 

 in the amount of oxygen liberated by 0.5 c.c. 

 of the different samples of blood from hy- 

 drogen peroxide, whereas chloroform produced 

 a very abrupt decrease during the first fifteen 

 minutes of narcosis as is indicated by the 

 great decrease in the amount of oxygen liber- 

 ated from 900 to 325 c c. 



We have shown that small amounts of chlo- 

 roform or ether added to blood in vitro destroy 

 the catalase of the blood very rapidly. We 

 have also shovsm that the liver is the organ 

 in which catalase is formed, given off to the 

 blood carried to the tissues. 



The explanation that suggests itself for the 

 decrease in the catalase of the blood produced 

 during chloroform and ether anesthesia is the 

 direct destruction of the catalase of the blood 

 by the anesthetic and the decrease output of 

 the catalase from the liver brought about by 

 injury of the liver by the anesthetic. The 

 more powerful and dangerous effect of chlo- 

 roform as an anesthetic is attributed to the 

 fact that chloroform is more potent than ether 

 in producing a decrease in catalase, both by 

 direct destruction of the catalase of the blood 

 and by injuring the liver, thus decreasing the 



