PHENOMENA OF ANAPHYLAXIS 575 



larger than the minimum sensitizing dose, the proportion between the 

 two having been placed by Doerr and Russ as 1 : 1000, i. e. } if 0.001 c.c. 

 of serum is injected intraperitoneally in order to effect sensitization, 

 1 c.c. injected by the same route ten or twelve days later would in all 

 probability kill a half -grown guinea-pig, whereas 0.1 c.c. subcutaneously 

 would be followed by serious symptoms. 



Rabbit. Reference has been made elsewhere to the pioneer work of 

 Arthus, who first described the local anaphylactic reaction about the 

 site of subcutaneous injection. He also described objectively the most 

 important symptoms of acute anaphylactic death in the rabbit, as well 

 as the more ordinary type, which ends in recovery. 



In acute and fatal anaphylactic shock in the rabbit Auer 1 found slow 

 respiration, weak or absent heart action, with fall in blood-pressure, 

 general prostration, the sudden falling of the animal on its side, a short 

 clonic convulsion, increased peristalsis, and expulsion in feces and urine. 

 Death is ascribed to a vascular or cardiac shock or to a failure of the 

 heart action of peripheral origin, mostly affecting the right side, and due 

 to a form of chemical vigor. The muscle may be gray, stiff, very tough 

 to the finger-nail, and non-irritable. Further evidence of the importance 

 of heart failure in anaphylaxis in the rabbit is furnished by the electro- 

 cardiographic study of Auer and Robinson. 2 Blood coagulability is 

 delayed. 



Rabbits are by no means so easily sensitized nor to so high a degree 

 as guinea-pigs. Non-fatal anaphylaxis accompanied by fall in blood- 

 pressure, increased heart-rate, and active intestinal peristalsis is readily 

 produced, but there is considerable uncertainty in inducing acute 

 anaphylactic death. Sensitization is usually effected by two or three 

 intravenous injections of 1 c.c. of serum at intervals of three days. In- 

 toxication generally follows an intravenous injection of 1 to 5 c.c. of 

 serum about four to six weeks later. Much smaller doses than these 

 may, however, be used, as was occasionally shown during immuniza- 

 tion of rabbits with erythrocytes for the production of hemolytic ambo- 

 ceptor, when minute traces of serum, escaping the washing process, 

 served to sensitize, and at a later injection produced acute anaphylactic 

 shock and death within a very few minutes. 



Cats. Anaphylaxis in the cat has been studied especially by 

 Schultz, 3 who observed that cardiac disturbances followed. Horse 

 serum, however, was found markedly toxic in effect, even in the un- 



1 Jour. Exp. Med., 1911, xiv, 476. 2 Jour. Exp. Med., 1913, xviii, 450. 



3 Jour. Phar. and Exper. Therap., 1911-12, 3, 302. 



