Fats 21 



this ordered cycle. Running through the whole set of complexities 

 is, in all likelihood, a number of genetical and constitutional factors 

 which provide the fine adjustment for the more cumbersome 

 homeostatic mechanisms. Each and every one of these guides and 

 catalysts have their work to do in the cell but we are profoundly 

 ignorant of the way in which they achieve their purpose. 



HOW MUCH AND WHAT KIND OF FAT ACCUMULATES 

 WHEN A CELL IS DAMAGED? 



Information about this key question is sadly lacking, largely 

 because analytical methods of the past were cumbersome and time- 

 consuming. Most of our knowledge is confined to the liver which 

 occupies a central position in the metabolism of lipids. The normal 

 liver contains about 3.5 g. neutral fat, 12-14 g. phospholipid, 0.25 g. 

 total cholesterol (mainly cholesterol esters) per 100 g. fresh tissue. 

 A fatty liver is considerably enriched in its lipid fractions, especially 

 in the neutral fats or glycerides, but the figures vary according to the 

 state of the cells, especially the water content and the extent of 

 associated necrosis. Thus the liver of rats poisoned with bromoben- 

 zene shows a decrease in total lipid, lecithin and cephalin, but an 

 increase of total cholesterol when necrosis is pronounced (Cor- 

 natzer and Gallo, 1956) . High lipid levels (22 per cent and over) 

 have been recorded in fatty livers, with reduction of glycogen, 

 pyruvic acid and a-keto-glutaric acid (Frunder et al., 1955) . The 

 extensive fatty change and necrosis in the liver induced by carbon 

 tetrachloride is associated with phosphatide increase followed by 

 decrease in the later stages (Schulze, 1952) . Potassium cyanide 

 gives a considerable reduction in the phosphatides of the rat's liver 

 and kidneys with marked reduction in oxygen uptake in their 

 tissues (Goebel et al., 1952) . A fatty liver of unknown origin in an 

 eight-year-old donkey contained 80 per cent dry weight lipids, 

 chiefly fats, but only 0.17 per cent phosphatides and 0.4 per cent 

 unsaponifiable fat. Fatty acid analysis showed myristic acid 0.3 per 

 cent, palmitic acid 36.2 per cent, palmitoleic acid 17.9 per cent, 

 stearic acid 3.7 percent and oleic acid 41.9 per cent (Bernhard and 

 Scheitlin, 1952) . Livers of rats receiving intravenous injections of 

 cerium and other rare earths with low atomic numbers develop 



