634 VI. OCCURRENCE OF LIPIDS IN THE ANIMAL 



an accumulation of excess fat in the liver." 547 The term was first employed 

 in 1935 by Best, Huntsman, and Ridout 552 to describe the action of choline 

 in the prevention and cure of fatty livers. 



Finally, physiologic and pathologic fatty livers can be differentiated by 

 the resultant effects on metabolism. When a physiologic fatty liver de- 

 velops as a result of fasting, hyperlipemia and ketosis appear. Anything 

 which accelerates the metabolism of carbohydrate will tend to abolish the 

 physiologic fatty liver. This is effected by the injection of insulin into the 

 diabetic animal, or by the administration of glucose or other metabolizable 

 carbohydrate to the animal having the physiologic type of fatty liver as a 

 result of complete starvation or of carbohydrate starvation. However, 

 lipotropic agents which ameliorate the condition of pathologic fatty livers 

 are entirely ineffective in the physiologic type. 553 - 554 



On the other hand, it has been stated that the animal with the pathologic 

 fatty liver does not ordinarily exhibit a ketosis or hyperlipemia, but fre- 

 quently has a hypolipemia. However, Deuel et al. m demonstrated that a 

 ketonuria does obtain in fasting rats having fatty livers as a result of a cho- 

 line-deficient diet. This endogenous ketonuria is "physiological," since 

 the same sex difference exists as in normal fasting human subjects, and in 

 rats having an exogenous ketonuria. The cholesterol esters and phospho- 

 lipids, particularly, are reported to be reduced 555 in the serum, while an un- 

 usually large proportion of the fat in the liver consists of phospholipids. 549 

 The pattern of the liver lipids varies consistently with the types of patho- 

 logic fatty livers, but depends upon the circumstance responsible for the ori- 

 gin of the condition. 520 - 556-559 The administration of carbohydrate has no 

 effect in reducing the liver lipids. In fact, Best and Hershey 560 indicated 

 that there is an increased glucose tolerance and a decrease of the insulin re- 

 quirement, in depancreatized dogs, associated with the development of 

 fatty livers. There is no increase in fat utilization when a pathologic fatty 

 liver exists. When the appropriate lipotropic agent is given, the fat leaves 

 the liver, the normal pattern of liver lipids is restored, the blood lipids return 

 to normal, and the fat depots become filled with the characteristic depot fat. 



552 C. H. Best, M. E. Huntsman, and J. H. Ridout, Nature, 135, 821-822 (1935). 



553 L. R. Dragstedt, C. Vermeulen, W. C. Goodpasture, P. B. Donovan, and W. A. 

 Geer, Arch. Internal Med., 64, 1017-1038 (1939). 



654 A. I. Lewin, Z. ges. exptl. Med., 96, 532-547, 548-560 (1935). 



555 1. L. Chaikoff and A. Kaplan, J. Biol. Chem., 106, 267-279 (1934). 



656 C. H. Best, H. J. Channon, and J. H. Ridout, J. Physiol., 81, 409-421 (1934). 



657 C. H. Best, M. E. H. Mawson, E. W. McHenry, and J. H. Ridout, /. Physiol, 86, 

 315-322(1936). 



568 E. P. Ralli, S. H. Rubin, and C. H. Present, Am. J. Physiol, 122, 43-47 (1938). 

 669 De W. Stetten, Jr., and G. F. Grail, J. Biol. Chem., 1U, 175-181 (1942). 

 660 C. H. Best and J. M. Hershey, J. Physiol, 75, 49-55 (1932). 



