Cause of Acute Anaphylactic Death in Guinea Pigs. 29 



chloride similar to the one administered to the surviving animal (B). 

 This means that the magnesium antagonizes the fatal effect of 

 barium. We are not ready to state definitely in what way this 

 action of magnesium is exerted. The poisonous effect of barium 

 is due to its action upon various functions and magnesium antago- 

 nizes some of them. We are engaged in the study of the parti- 

 culars of the subject. 



19 (429) 



A demonstration of the cause of acute anaphylactic death in 



guinea pigs. 



By J. AUER and P. A. LEWIS. 



\_From the Department of Physiology and Pharmacology of the 

 Laboratories of the Rockefeller Institute for Medical 

 Research^ 



In a preliminary communication, 1 we pointed out among other 

 things, (1) that the acute anaphylactic death of guinea pigs was 

 due to asphyxia ; (2) that this asphyxia was caused by the develop- 

 ment of a stenosis in the pulmonary air passages, so that practi- 

 cally no air enters or leaves the lung in spite of violent diaphrag- 

 matic contractions, the lungs remaining distended even after 

 opening of the chest; (3) that this stenosis was caused by a 

 peripheral action of the second or toxic injection, for the same 

 stenosis and striking lung picture was obtained after destruction of 

 the cord and medulla, artificial respiration being maintained ; (4) 

 that this stenosis was probably caused by a tetanic contraction of 

 the muscles of the bronchioli. 



In the demonstration, a sensitized guinea pig was immobilized 

 by curarin and artificial respiration instituted. This respiration was 

 of such a strength that the chest expanded and collapsed well. 

 Within from one to two minutes after the injection of one cubic 

 centimeter of normal horse serum, the respiratory oscillations of 

 the chest gradually became less and less and finally stopped, al- 

 though the respiration machine delivered the air with the same 

 rate, strength and amount as before ; now the chest remained 

 motionless in an inspiratory condition, thus demonstrating that the 



1 Auer and Lewis, Jour, of the American Med. Assoc., 1909, liii, 458. 



