CHAPTER XXV 

 CYTOTOXINS 



IN Chapter XXIII the cytolysins in general were considered, 

 especially their theoretic structure and the mechanism of their action. 



It will be remembered that the general name "cytolysin" is applied 

 to an amboceptor or antibody of the third order of receptors that is 

 capable of preparing its antigen for the disintegrative or lytic action of a 

 complement. The two best known and most important members of 

 this group of antibodies have been considered, namely, the hemolysins 

 and the bacteriolysins. 



Following the discovery of the hemolysins and the bacteriolysins 

 and of the mechanism of their action, it was not long before similar 

 studies were undertaken with other cells, with the result that attempts 

 have been made to prepare immune cytolytic serums for practically 

 every organ of the body. This outcome was but natural, in view of the 

 enormous theoretic importance of specific cytolysins, not only from the 

 additional light that may be thrown upon physiologic and pathologic 

 processes in general, but also from the standpoint of specific therapeutics. 



Nomenclature. While actual lysis or solution of erythrocytes and 

 bacteria may be brought about by antibodies of this order, yet actual 

 solution is not apparent with most other body-cells, although a distinct 

 toxic action may be observed. For instance, an antispermatozoa 

 serum will cause these cells to lose their motility, but does not actually 

 dissolve them. Hence the name cytotoxin has been applied to these 

 immune serums. This is probably a better term than cytolysin; but 

 it is to be remembered that, so far as is now known, both cytolysins and 

 cytotoxins are antibodies that possess the same nature and structure, 

 except that in the former group the process is complete and ends in 

 actual lysis of the cell. The term cytolysin is, therefore, more appro- 

 priately applied to the bacteriolysin and hemolysins; whereas the term 

 cytotoxin is reserved for those immune serums that injure their cells without 

 complete lysis (a toxic action), such as nephrotoxin, hepatotoxin, etc. 

 This chapter is mainly concerned with the latter group. 

 i Nature and General Properties of Cytotoxins. As previously 

 stated, cytotoxins are amboceptors or antibodies of the third order, and 



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