PROTEIN SENSITIZATION OR ANAPHYLAXIS 323 



were not of a high order, another pig could be tried at once, 

 or after a few days longer incubation period. When a 

 uterus was found which gave a large and clear response 

 to, say, 1 in 100,000 human serum, the other horn, kept 

 meanwhile in warm oxygenated Ringer, could be suspended 

 in a small volume such as 10 c.c. of Ringer's solution. A 

 dose of the suspended material could then be added, and 

 if no reaction were produced it would be clear that the 

 dose contained less than 0.0001 c.c. of human serum, which 

 should be sufficient evidence, in any ordinary case, that 

 the blood under examination was not human. If, on the 

 other hand, a decided response were produced, it would 

 only be necessary to test further the action of the specimen 

 on a normal uterus, so as to exclude primary non-specific 

 toxicity." 



It has been demonstrated by Manwaring, 1 and confirmed 

 by Voegtlin and- Bertheim 2 that dogs sensitized to horse 

 serum do not respond on reinjection when the liver is 

 excluded from the circulation. 



Theories. Hamburger and Moro at one time suggested 

 that the first injection leads to the formation of precipitins, 

 and that on reinjection precipitates are formed, and induce 

 the anaphylactic symptom-complex by the formation of 

 capillary emboli. The formation of specific precipitins is 

 a reaction which occurs in vitro, but not in vivo. Besides, 

 the symptoms of anaphylaxis are not those due to emboli, 

 and finally, no emboli are formed. 



Gay and Southard thought that as a result of the first 

 injection there remains in the circulation a protein rest 

 which they named "anaphylactin," and that this continues 

 to stimulate the cells, creating an abnormal affinity for 

 the homologous protein which on reinjection leads to 

 anaphylactic shock. The transfer of this "anaphylactin" 

 to a fresh animal was supposed to explain passive anaphy- 

 laxis, a phenomenon first studied by these investigators. 



1 Zeitsch. f. Immunitatsforschung, 1910, viii, 1. 



2 Jour. Pharm., 1911, ii, 507. 



