482 IMMUNOLOGY 



in studying anaphylaxis in this anhnal. Kabler and Sherwood 

 (1933) reinvestigated the subject after discovering that the 

 Brodie reaction is not elicited by the intravenous injection of 

 relatively large doses of crystalline egg albumen. They attempted 

 to sensitize actively twenty adult eats and obtained entirely nega- 

 tive results. They were, however, able to sensitize passively 40 

 per cent of a series of eats to the same antigen by means of high 

 titered immune rabbit serum. As a result of further work, they 

 conclude that they were unable to sensitize cats actively because 

 the latter did not produce sufficient antibodies. The results of 

 their physiological studies of anaphylaxis in the passively sen- 

 sitized cat under ether anesthesia are partly summarized as 

 follows : 



1. The characteristic blood pressure response is a profound drop 

 followed by a slow return to normal. There may be a temporary- 

 return toward or to normal followed by a second drop and final 

 return. This is spoken of as the "three-phase" curve. 



2. During the period of low blood pressure there is a marked 

 slowing of the heart rate. 



3. There is a progressive decrease in the body temperature 

 throughout the experiment. 



4. There is an increase of intestinal pressure in the cannulated 

 loop of small intestine. This suggests an active participation of 

 the intestinal smooth muscle in the anaphylactic phenomenon. 



5. The intracystic (bladder) responses are variable. 



6. The kidney volume is consistently decreased during shock. 

 This suggests an active constriction of the renal blood vessels. 



7. There is no characteristic prolongation of the clotting time 

 of the blood such as is observed in the dog. 



8. The smooth muscle reaction can be demonstrated in vitro 

 when excised strips are removed from animals that can be shown 

 to be sensitive by the intravenous injection of antigen. 



Anaphylaxis in Rats. — Arthus (1903) was the first to study 

 the effects of repeated injections of a foreign antigen into white 

 rats. He claimed that he was able to produce specific sensitiza- 

 tion. Novy and De Kruif (1917) were unable to confirm his re- 

 sults. In 1924 Parker and Parker, working in Zinsser's laboratory, 

 succeeded in producing definite anaphylactic shock in white rats. 



