HEMOLYSIS AND PHAGOCYTOSIS OF RED BLOOD CORPUSCLES I3 



This is corroborated by the results of experiments with normal 

 haemolytic sera. The serum of a normal guinea-pig is slightly 

 haemolytic for the red blood cells of the rabbit. The serum of a normal 

 guinea-pig, the washed red blood cells of a rabbit, and washed human 

 leucocytes, were employed for phagocytic tests in vitro. It was found 

 that many of the leucocytes employed as the phagocytic agents 

 contained blood shadows, that is, instead of red blood cells they 

 contained clear circular spaces. In most films, if 100 polymorpho- 

 nuclears were counted, a few contained one or two apparently unchanged 

 red cells, and a few contained erythrocytes, more or less haemolysed. It 

 was thus possible to trace the gradations between apparently normal 

 red cells lying in the polymorphonuclear leucocytes and clear round 

 spaces representing the erythrocytes in a haemolysed condition. 



If, however, with such a serum heated at 50° C. - 60° C. for 15 

 minutes, phagocytic tests were performed, no evidence of phagocytosis 

 was observed. Neither blood shadows nor red blood cells were to be 

 seen in the leucocytes, except in a very few instances, where one or two 

 polymorphonuclears contained a single unchanged erythrocyte. The 

 opsonic action of the serum had been abolished. Yet there was 

 undoubtedly a considerable amount of haemolytic amboceptor present, 

 since it is not destroyed by heat at the temperature mentioned above, 

 and therefore we cannot assume that abolition of the opsonic effect of 

 the blood serum is due to destruction of the haemolytic amboceptor. 



That a destruction of the " opsonin " takes place may be seen from 

 the following experiment : — The opsonic power of the serum of a 

 guinea-pig unheated on the one hand and on the other heated at 55° C. 

 for 15 minutes, on the washed erythrocytes of the rabbit, was deter- 

 mined in the usual manner twice a day for three consecutive days, the 

 amount of phagocytosis being estimated by the percentage of poly- 

 morphonuclears containing blood shadows or red blood cells more or 

 less haemolysed. 



(313) 



