44 The Chemistry of the Injured Cell 



AMYLOID INFILTRATION 



This mysterious condition presents a challenge that has defied 

 investigators for many years. The composition of amyloid is still 

 not known, although it probably consists of proteins and sulphated 

 mucopolysaccharides akin to heparin and it possesses a micellar 

 structure. When animals are injected for a long time with bacteria 

 or their products, foreign proteins such as casein, ribonucleate or 

 antitoxin, they develop amyloid disease. While this is happening 

 the blood undergoes a striking dysproteinaemia characterised by 

 increase of serum p globulin and a fall in albumin. Serum hexo- 

 samine also increases. Amyloid disease can be made to disappear; 

 the p globulin level falls as the amyloid is resorbed (Richter, 1956; 

 Giles and Calkins, 1958) . But what lies behind these disturbances 

 has still to be discovered. Some workers believe that disturbed func- 

 tion in the cells of the reticulo-endothelial system cause the blood 

 changes and the associated amyloid infiltration of organs such as 

 the liver, kidney, spleen and intestine. 



DISTURBANCES DUE TO TOXIC ACTION ON CELLS 



We have already discussed the best investigated examples of this 

 group and now add a few more instances. Carbon tetrachloride, 

 hepatotoxic serum and x-rays increase the cytoplasmic p globulins 

 when their action is mild but lead to a decrease with an increase in 

 y globulins when severe (Demling, 1954). Carbon tetrachloride 

 induces a considerable rise in RNA and a smaller increase in DNA 

 in the liver of rats fed on protein-free or 23 per cent casein diet in 

 forty-eight hours when regeneration is going on actively. The RNA 

 increase is much less in fasting animals (Campbell and Kosterlitz, 

 1952) . Spectrophotometric analysis discloses a build up of DNA 

 in the nucleus before the cell divides and persistent abnormal 

 nuclear masses after regeneration is complete (Hoffmann et al., 

 1955) . A marked decrease in RNA has been recorded in the liver 

 cells of dogs damaged by administration of phosphorus (Barone 

 and Parisi, 1954) . We have noted elsewhere the apparent affinity 

 of triethyltin for liver proteins and the interesting suggestions that 

 may arise from this demonstration. Similar affinities between car- 

 cinogenic agents, especially certain azo dyes and thioacetamide, 



