Table 62. — -Liver jat in rats of different body 

 weight maintaining weight on SPM, SPB, and 

 SPPB diets 



Diet and body weight 

 (grams) 



Rats 



Average 



body 



weight 



Liver fat 

 on dry- 

 weight basis 



SPM: 



Less than 500 . 

 500 to 599 



Number 



2 

 3 

 4 

 2 



3 



2 



7 

 1 



3 

 1 

 5 



7 



Grams 



434 

 575 

 659 



774 



441 

 549 

 654 

 740 



444 

 550 

 667 



777 



Percent 



16. 9 

 20. 8 



600 to 699 .- 



23. 



700 and over 

 SPB: 



Less than 500- 



500 to 599 --. 



29. 7 



19.6 

 20. 1 



600 to 699. 



19. 



700 and over . . 

 SPPB: 



Less than 500 

 500 to 599 



19. 



17.3 

 19. 7 



600 to 699 _- 



23. 6 



700 and over 



25. 5 



the same whether the diets contained 10 or 41 

 percent liver. 



Reussner and Thiessen (156) reported 29.3 

 percent fat in the large livers from rats fed an 

 egg and bacon diet, in contrast to 12.5 percent 

 for a cereal and milk diet and 15.1 percent for a 

 milk diet. These differences in liver fat were not 

 related to the level of fat in the diet. In spite of 

 the high liver fat, the bacon and egg diet resulted 

 in good survival of rats on long-term feeding. 



Okey (140) fed diets containing 1 percent 

 cholesterol to rats from weaning throughout middle 

 and old age, and observed no significant differ- 

 ences in growth, health, and survival between 

 control and cholesterol-fed rats in spite of the high 

 fat and cholesterol content of the livers of the 

 latter. Histological examination of the livers 

 showed fatty infiltration rather than degeneration 

 of functioning tissues. 



Ridout, Lucas, Patterson, and Best (157) re- 

 ported a progressive increase with increasing 

 dietary cholesterol in the accumulation of both 

 glycerides and cholesterol esters in the livers of 

 rats. 



Okey and Lyman (143) reported the results of 

 feeding 5, 10, and 15 percent coconut oil or 

 cottonseed oil with or without added cholesterol. 

 The response of female rats was occasionally 

 quite different from males and, for comparison 

 with the results reported in this publication, only 

 the results with males will be discussed. In the 

 absence of dietary cholesterol, elevated liver fats 

 were observed only when coconut or cottonseed 

 oil was fed at the 15-percent level. In the 

 presence of cholesterol, liver lipids and total 

 cholesterol increased with increasing concentra- 

 tion of dietary fat and were consistently higher 

 with cottonseed oil than with coconut oil. 



Okey, Lyman, Harris, and others (145) also 

 compared the response of rats to 13 different fats 



with iodine numbers varying from 8 to 143, each 

 fed at the 10-percent level. Liver fat and choles- 

 terol values in the absence of dietary cholesterol 

 were not exceedingly high with any of the 13 

 edible fats investigated. There was a tendency to 

 relatively low values with the more highly satu- 

 rated fats. When cholesterol was included in the 

 diet, liver fat and cholesterol increased; the 

 increase in cholesterol was generally smallest in 

 rats fed fats with low iodine numbers. According to 

 the author, not one but a number of factors appear 

 to influence the effect of composition of dietary 

 fat on liver lipids. 



Choline has been found effective in preventing 

 various types of fatty livers in rats (24). In a 

 diet free from cholesterol, Best, Lucas, Patterson, 

 and Ridout (23) reported that regardless of the 

 kind of fat used, total liver lipids were essentially 

 normal when the amount of choline chloride pres- 

 ent was between 0.12 and 0.16 percent. According 

 to Benton, Harper, and Elvehjem (19), the type of 

 dietary fat had little effect on the deposition of 

 liver fat when the diet of the rat contained 

 adequate amounts of choline and protein. Rid- 

 out, Lucas, Patterson, and Best (157) found that 

 the amount of choline needed to maintain liver 

 glycerides within or slightly above normal when 

 the diet contains cholesterol does not necessarily 

 prevent the accumulation of cholesterol esters in 

 the liver. 



Jackson (100) observed a tendency to fatty 

 livers with degenerative abnormalities when rats 

 were fed a diet containing 80 percent sucrose. 

 This diet, however, did not appear detrimental to 

 growth and general health. On diets containing 

 45 percent sucrose or starch, no marked differ- 

 ences were observed in size or histological structure 

 of livers or kidneys. 



Summary. — The results with BHE rats reported 

 in this publication indicate that age may or may 

 not be a factor in the percentage of fat in the 

 liver, depending on the diet under investigation. 

 The increase that occurred with age on some of 

 the diets appeared to be related to an increase in 

 the number of extremely heavy animals on these 

 diets. Differences in liver fat were not neces- 

 sarily related to level of dietary fat. The per- 

 centage of fat in the diet containing beef was 

 somewhat higher than that in the diets containing 

 egg, milk, or peanut butter, but liver fat for rats 

 fed this diet was generally low when compared 

 with the results for the other diets. Liver fats 

 were high in rats fed the diet containing 25 per- 

 cent egg and much higher than were obtained with 

 the extremely high fat diet consisting of 100 per- 

 cent egg yolk. The results with rats fed 8 or 16 

 percent HVO, lard, or butter also showed no 

 consistent relation between level of dietary fat 

 and liver fat, although these results were compli- 

 cated by the weight loss occurring in moribund 

 rats. 



Damaged kidneys were a frequent finding in 

 BHE rats regardless of diet, and they were not 



75 



