HEMOLYSIS OR ERYTHROCYTOLYSIS 191 



This hemolysis occurs both in the test-tube and in the body, in 

 the latter case causing severe anatomical changes or even death. 

 In all respects the mechanism of hemolysis by serum seems to be 

 identical with that of bacteriolysis. Two substances are con- 

 cerned, one, the amboceptor, which resists heat and which is 

 increased by immunizing; the other, complement, which is 

 destroyed at 55 and which is present in normal serum. In 

 this case the substances may be referred to as hemolytic ambo- 

 ceptors and hemolytic complements. 1 



In spite of the availability of these particular cytolytic sub- 

 stances for study, very little has been learned of their exact 

 nature and properties. It is known that amboceptor is com- 

 bined with the red cells in a certain sense quantitatively, a cer- 

 tain amount being required to saturate a given amount of cor- 

 puscles so that they will all be hemolyzed when complement is 

 added ; and that this reaction is complete in less than fifteen 

 minutes at 45. What change this addition of amboceptor 

 brings about in the corpuscles is unknown. It has also been 

 shown that at the affinity between the amboceptor and the 

 corpuscle is greater than it is between amboceptor and comple- 

 ment, so that it is possible at this temperature to remove all the 

 amboceptor from a serum by treating it with red corpuscles, and 

 thus we can obtain complement free from amboceptor. This 

 experiment also shows that the two bodies exist side by side in 

 the serum without combining, and that combination occurs only 

 after the amboceptor has become united to the erythrocyte. 



The Atnboceptor. Amboceptor is, as a rule, destroyed 

 by heating to 70 or higher. Its place of origin is unknown. 

 Metchnikoff holds that it is derived chiefly from the leucocytes, 

 in support of which view is the fact that leucocytes dissolve red 

 corpuscles after ingesting them ; however, other phagocytic cells 

 have the same power, particularly endothelial cells, and it is an 

 open question whether the intracellular digestion of engulfed cells 

 is the same process as extracellular hemolysis ; probably it is 

 not, for there seem to be more disintegrative changes in intra- 

 cellular digestion than in hemolysis. Quinan 2 found that the 

 diffusible constituents of hemolytic serum played no role beyond 

 that of maintaining osmotic pressure. He was unable, however, 

 to localize the immune body in any of the proteid constituents. 

 Kyes found that a combination of hemolytic amboceptor of 

 venom and lecithin gave no biuret reaction. The amboceptors 



1 Bang and Forssmann (Hofmeister's Beitr., 1906 (8), 238) do not accept 

 the prevailing view. 



2 Hofmeister's Beitr., 1904 (5), 95. 



