372 HEMOLYSINS 



Noguchi, preserves the hemolytic activity in a remarkable degree. 

 Heating an immune serum at 56 C., for half an hour, as in the process 

 of inactivating complement, does not materially injure the hemolytic 

 activity of a potent serum. A temperature of 70 C. or above may 

 cause deterioration and finally destroy the amboceptors. 



As was previously mentioned, hemolytic amboceptors possess a 

 great affinity for the receptors of their homologous corpuscles, and will 

 readily unite with them at a low temperature. At incubator temperature 

 the union is quite rapid, so that corpuscles may be "sensitized" within 

 half an hour. 



Source of Hemolysins. As has been stated elsewhere, Metchnikoff 

 regards the leukocytes as the source of fixateur or amboceptor forma- 

 tion. Bulloch found that the amount of hemolytic amboceptor in a 

 serum runs parallel with the number of mononuclear leukocytes, and he 

 regards this as an indication of the activity of the lymphoid tissue in 

 general, which he considers as the main source of amboceptor formation. 

 While it is probable that endothelial cells and mononuclear leukocytes 

 are especially concerned in the process, our own investigations in this 

 field would indicate that the process is more general, being participated 

 in by cells of other tissues which possess suitable combining affinities 

 for the alien corpuscles. 



Antihemolysins. A further step in the study of hemolysins, but one 

 more of theoretic than of practical interest, was the discovery of anti- 

 hemolysins. By injecting guinea-pigs with normal rabbit serum con- 

 taining amboceptors for ox blood, Bordet secured a serum that inhibited 

 the action of anti-ox immune serum. Ehrlich and Sacks, by injecting a 

 goat with normal rabbit serum, likewise secured a serum that acted as 

 an anti-amboceptor against immune hemolytic amboceptors for ox 

 blood. Ehrlich argued that the anti-amboceptor acted against the com- 

 plementophile group of the amboceptor, which prevented union with a 

 complement from taking place. This view was advanced in support of 

 his theory concerning the two-armed character of the amboceptor and 

 that an anti-amboceptor may be produced against either the cytophile 

 or the complementophile group or both. In these particular serums, 

 however, the investigators may have been working with an anticomple- 

 ment instead of an anti-amboceptor. 



A specific hemolysin one, for example, specific for dog blood, de- 

 rived by treating a rabbit with dog cells is highly toxic for dogs, being 

 capable of producing hemolysis in vitro and a clinical condition known 

 as hemolytic jaundice. It is possible, however, gradually to immunize 



