SOME ASPECTS OF ANAPHYLAXIS 437 



peutic intervention is possible if the investigator is in the dark concern- 

 ing these points. The first attempt to study anaphylaxis more thor- 

 oughly was made by Arthus in 1903. This investigator showed for the 

 first time that anaphylaxis in rabbits is characterized by a marked drop 

 in blood pressure. This drop in blood pressure Arthus considers the 

 most delicate indicator of anaphylaxis. In 1910 Cesaris-Demel de- 

 scribed the effects which were produced when the excised heart of a 

 sensitized rabbit was perfused with a dilute solution of the same pro- 

 teid which caused sensitization. He stated that such a heart rapidly 

 decreased the amplitude of its beat and assumed a condition of greater 

 tonus ; toxic effects were also noted on normal hearts, but by no means 

 as pronounced as in sensitized hearts. In 1911 Auer showed inde- 

 pendently that the heart of an intact anaphylactic rabbit of sufficiently 

 high sensitization rapidly fails to do its work, and that the animal suc- 

 cumbs for this reason. The functional basis for this heart failure was 

 shown to be a complete or almost complete loss of direct irritability of 

 the heart ventricles. On macroscopical examination of the heart 

 muscle, the right ventricle shows a toughening of the muscle bands on 

 its endocardial surface when scraped by the finger nail. The left ven- 

 tricle does not show this toughening, except now and then on its pap- 

 illary muscles. The same observer also demonstrated that these cardiac 

 changes were obtained after section of the vagi, and after destruction 

 of the central nervous system, thus proving that the fatal cardiac 

 reaction was not due to central, nervous influences, but was of periph- 

 eral origin. He also noted the absence of any marked disturbance of 

 the lungs in anaphylactic rabbits. 



In dogs, Biedl and Kraus, and later Arthus, proved that the main 

 symptom of anaphylaxis was a rapid, profound and long-lasting drop 

 in blood pressure. Experimental evidence led Biedl and Kraus to the 

 view that this fall was due to a paralysis of the vasomotor endings in 

 the splanchnic area. Associated with this drop in blood pressure the 

 same observers noted a diminution in the number of leucocytes, and an 

 extreme loss of coagulability of the blood. Blood drawn from a dog 

 during the anaphylactic state remained fluid for many hours, some- 

 times days. The respiratory function showed no noteworthy altera- 

 tions. The dogs recovered as a rule. 



The functional alterations produced by anaphylaxis in guinea-pigs 

 is entirely different from those observed in rabbits and dogs. In the 

 guinea-pig, Auer and Lewis showed that the functional interference 

 occurs in the lungs. Within a few seconds after the intravenous injec- 

 tion of an adequate " second " dose the animal shows greater and greater 

 difficulty in getting air into and out of its lungs, until finally a stage is 

 reached where no air at all enters on inspiration and this in spite of the 

 fact that the animal makes most violent inspiratory attempts. Three 



