CYTOLYTIC SERA 235 



Endotheliolytic Serum.--Every attempt at imniuniziiiK an animal with any sort 

 of fixed tissue must of necessity involve the injection of endothelial cells as well as 

 the cells specific to the tissue studied. Therefore, it is possible that cytotoxic 

 serum so obtained will contain endothelial toxins, and so complicate any results of 

 intra vilam experiments. There is every reason to believe that endotheliolytic 

 substances are produced in this way. Ricketts "" found that serum of animals 

 immunized against lymph-glands was toxic to endothelial cells, which was indicated 

 by hemorrhages at the point of injection, and marked desquamation of endothelium 

 when the injection was made into a serous cavity. In snake-venom poisoning the 

 extensive hemorrhages are also due to an endotheliolytic principle, called by Flexner 

 hc7nnrrhagin. 



Lymphatolytic Serum. — This serum has been studied by Ricketts and by Flex- 

 ner, who immunized animals with lymph-glands. As might be expected from the 

 structure of the injected glands, the resulting serum contained endotheliotoxin, 

 leucocytotoxin, hemolysin, hemagglutinin, leucocyto-agglutinin, and precipitins. 

 When injected into animals, this serum has a marked effect upon the spleen and 

 lymph-glands, producing great enlargement and congestion of these structures. 

 The bone-marrow is also somewhat affected, and when marrow is used in immuniz- 

 ing, the myelotoxic serum produces marked proliferative changes in the lymph- 

 glands as well as in the marrow. 



Nephrolytic Serum. — It has been claimed that if a kidney is destroyed by li- 

 gating its vessels or ureter, the remaining kidney develops serious degenerative 

 changes, which are not present if one kidney is entirely removed. This has been 

 attributed to the development of nephrotoxic substances produced in reaction to 

 the absorption of the injured renal tissue that has been left in the body. Other 

 methods of renal injury have been thought to produce similar effects, and serum of 

 animals with kidney disease was said to injure the kidneys of normal animals. 

 Upon this basis it has been thought possible to explain the progressive nature of 

 the chronic nephritides as the result of nephrotoxins produced through the ab- 

 sorption of the injured cells, which nephrotoxins injure still other renal cells. ^^ 

 Such a process, however, involves the production of cell toxins in an animal that 

 are toxic for its own cells, that is, autocytotoxins; and as it has so far been extremely 

 difficult to produce autolysins of other sorts, it is not altogether probable that the 

 kidney is an exception. Furthermore, Pearce^* was unable to produce isonephro- 

 toxins, and could not corroborate the statements as to the changes said to have 

 been found in the remaining kidney after ligating the vessels of its mate. He 

 did obtain an active heteronephrolysin, but also found that immunization with 

 liver produced nearly as actively nephrolytic serum as did immunization with 

 kidney. 



Neurolytic Serum. — Even as highly specialized cells as those of the nervous 

 tissue seem to produce a reaction with the formation of immune bodies. Perhaps 

 the most positive results are those of Ricketts and Rothstein,^^ who found that 

 serum of rabbits immunized against the brains or cords of guinea-pigs w'as highly 

 toxic when injected into the vessels of guinea-pigs, causing death with various 

 symptoms only explainable on the assumption of nervous lesions. Microscopi- 

 cally, the ganglion cells showed marked changes in those animals that survived 

 the injection long enough. All the results so far obtained have been with hetero- 

 geneous serum. 3s Venoms, particularly that of cobra, possess strong neurolytic 

 substances that are the chief toxic agents in most of the venoms (rattlesnake venom 

 excepted). 



Thy rely tic Serurh. — There are but few reports on this serum, but that of 

 Portis^' indicates that after removal of all hemolysis as a factor there do occur 

 changes, in the nature of excessive absorption of colloid, and proliferation after 

 the order of that seen in thyroid regeneration. However, the clinical pictvire of 

 thryoidectomy was not produced in any case, and the anatomic changes w'ere 

 not great. By immunizing against nucleoproteins derived from thyroid tissue, 



" See Kapsenberg, Zeit. Immunitat., 1912 (12), 477. 

 " Univ. of Penn. Med. Bull., 1903 (16), 217. 

 55 Trans. Chicago Path. Soc, 1903 (5), 207. 



'^ An attempt to obtain a specific neurotoxin with corpus striatum was un- 

 successful. (Lillian Moore, Jour. Immunol., 1916 (1), 525.) 

 " Jour. Infectious Diseases, 1904 (1), 127. 



