HEMOJA'l<Ii^ BY SERUM 219 



serum. In this case tlie substances may be referred to as hemolytic 

 amboceptors and hemolytic complements. 



In spite of the availability of these particular cytolytic substances 

 for study, very little has been learned of their exact nature and 

 properties. It is known that amboceptor is combined with the red 

 cells in a certain sense quantitatively, a definite amount being re- 

 quired to saturate a given amount of corpuscles 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 addi- 

 tion of amboceptor brings about in the corpuscles is unknown. It 

 has also been shown that at 0° the alifinity between the amboceptor 

 and the corpuscle is greater than it is between amboceptor and com- 

 plement, 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 experi- 

 ment also shows that the two bodies exist side by side in the serum 

 without combining, and that combination occurs only after the ambo- 

 ceptor has become united to the erythrocyte. Hemolysis by immune 

 sera takes place best in a medium with a reaction corresponding to 

 that of the blood, acids being more harmful than alkalies; with un- 

 favorable reaction the complement does not unite with the ambo- 

 ceptor, although the latter unites with the corpuscle.-'-* 



The Amboceptor. — Amboceptor is, as a rule, destroyed by heating 

 to 70° or higher.-""^ Its place of origin is unknowai. ]\Ietchuikoff 

 holds that it is derived chiefly from the leucocj'tes, in support of which 

 view is the fact that leucocytes dissolve red corpuscles after ingest- 

 ing them ; however, other phagocytic cells have the same power, par- 

 ticularly endothelial cells, and it is an open question whether the in- 

 tracellular digestion of engulfed cells is the same process as extracel- 

 lular hemolysis; probably it is not, for there seem to be more disin- 

 tegrative changes in intracellular digestion than in hemolysis. Qui- 

 nan ^° found that the diffusible constituents of hemolj^tic serum 

 played no role beyond that of maintaining osmotic pressure. He 

 was unable, however, to localize the immune body in anj' of the pro- 

 tein constituents, and Liebermann and Fenyvess}* ^^ believe that they 

 have obtained the amboceptor in a protein-free condition, in which 

 it behaves like a weak acid. Amboceptors are insoluble in lipoids or 

 lipoid solvents (Meyer), ^- and they move towards the cathode in an 

 electric field, as do other antibodies.^^ The amboceptor complement 

 reaction resembles a bimolecular reaction which is accelerated by its 



29Michaelis and Skwirsky, Zeit. ImnumitUt.. 1900 (4K .357. 

 ' 29a Ultraviolet lio^ht destroys immune hemolysin (Stines and Ahelin, Zeit. 

 Immunitiit., 1914 (20), 598).' 

 " 30 Hofmeister's Beitr., 1904 (5), 95. 



3i,Jahresber d. Immunitat., 1911 (7), 2. 



32 Ibid., 1909, Vol. 3. 



33 Teague and Buxton, Jour. Exper. [Med.. 1907 (9), 254. 



