340 



CYTOLYSINS 



Varieties of Cytolysins. The cytolysins produced by bacteria are 

 known as bacteriolysins, i. e., antibodies producing disintegration and 

 lysis of bacteria. The cytolysins known as hemolysins cause lysis or 

 hemolysis of the erythrocytes. Similar cytolysins may be formed for 

 practically all cells, such as leukocytes, epithelium, liver, kidney, spleen, 

 etc., and to these the general name cytotoxin has been given; thus we 

 have leukotoxin, hepatotoxin, nephrotoxin, neurotoxin, etc., these 



FIG. 95. FORMATION OF CYTOLYSINS (HEMOLYSINS, BACTERIOLYSINS, CYTOTOXINS). 



The central white area represents a molecule of a cell; the shaded portion repre- 

 sents the cell itself; the surrounding area represents the body-fluids about the cell. 



R, Receptor of the molecule '(third order) ; R 2 , overproduction of receptors, which 

 are being cast off; A, a cast-off receptor which now constitutes the antibody or am- 

 boceptor; C, molecule of complement free in the body-cells and body-fluids; A 2 A 4 , 

 amboceptors in combination with molecules of a cell (antigen) and a complement; 

 A 3 , an amboceptor in combination with a molecule of a cell. The cell (antigen) is 

 now said to be sensitized. Lysis does not occur because a complement is not united. 



terms being more nearly correct and expressive of the actual mechanism 

 by which their action is produced. 



Nomenclature. In no other field of immunity have so many differ- 

 ent names been applied to the same substances as have been applied to 

 this order of antibodies. This confusion of terms, added to the various 

 interpretations placed upon their significance, has rendered the subject 

 incomprehensible to those not specially interested. 



The ferment-like and thermolabile substances present in all serums 

 and actively concerned in lytic processes have been given the name of 



