504 CYTOTOXINS 



complement-fixation and the epiphanin reactions and that of observing 

 the influence of cytotoxic serums upon cells grown in vitro (Lambert). 



Specificity of Cytotoxins. As has been stated elsewhere, the hemoly- 

 sins and the bacteriolysins are highly specific, especially the former 

 group. With the cytotoxins, however, this specificity is not observed. 

 Most cytotoxic serums are also hemolytic, notwithstanding the fact that 

 careful precautions have been taken to remove, so far as possible, all 

 traces of blood from the inoculum during the process of immunization. 

 Metchnikoff found a spermatotoxic serum to be also hemolytic, but he 

 believed that this property could be removed by treating the immune 

 serum with the corresponding corpuscles, and in this manner dissolve 

 out the hemolysin. Numerous other investigators have found, however, 

 that cytotoxic serums may attack the cells of other organs, as well as 

 those that have been used as their antigens. 



The subject has been very carefully investigated by Pearce. 1 The 

 injection of an antidog nephrotoxic serum prepared by immunizing 

 rabbits with washed dog kidney is followed by the development of a 

 tubular nephritis, with albuminuria and occasionally hemoglobinuria, 

 and accompanied by granular degeneration of the liver. These serums 

 are usually hemolytic in vitro. Similarly, in a study of hepatotoxic 

 serums, Pearce found that the most striking lesions were referable to 

 the hemagglutinating and hemolytic properties of the serum, causing 

 thrombosis, embolism, and hemorrhages, whereas secondary necroses 

 may be caused by a direct toxic action of the serum on certain parenchy- 

 matous cells. 



Pearce, Karsner, and Eisenbrey found that the serums of rabbits 

 injected repeatedly with the nucleoproteins, globulins, and albumins of 

 the liver and kidney of the dog, gave no evidence of organ specificity 

 in vitro or in vivo experiments. These investigators were not able to 

 support the view put forward that nucleoproteins play an important 

 part in the production of cytotoxic immune serums. 



Lambert 2 has recently studied the subject with cultures of rat sar- 

 coma and rat embryo skin and their immune serums, and found that 

 these cytotoxins were not specific for the tissue injected. 



These results are not 'surprising when it is remembered that all the 

 body-cells have a common origin, and that, although the cells of various 

 organs may differ considerably in morphologic and functional characters, 

 they have certain receptors in common, and, as Pearce originally main- 



1 Jour. Exper. Med., 1914, xix, 277. 



2 Univ. Penna. Med. Bull., 1903, xvi, 217; Jour. Med. Research, 1904, xii, 1 



