682 VI. OCCURRENCE OF LIPIDS IN THE ANIMAL 



a'. Thiamine Fatty Livers: McHenry 855 found that fatty infiltration of 

 the liver failed to occur on choline-free diets if thiamine was also absent. 

 Rats on such a dietary regimen lost weight. However, if thiamine supple- 

 ments were given to the animals, their appetites were restored, the animals 

 gained weight, and fatty livers developed. These fatty livers could be pre- 

 vented by choline. 856 The intensity of the fatty infiltration was to some 

 extent dependent upon the amount of fat in the diet, 856,857 but it also oc- 

 curred on fat-low diets. The fatty infiltration was increased by the simul- 

 taneous administration of riboflavin and pyridoxine. 



Although McHenry 856 concluded that a possible explanation for the 

 action of thiamine in fattening livers in rats receiving high carbohydrate 

 diets would be that this vitamin promotes the synthesis of fat from car- 

 bohydrate, Peters and Van Slyke 549 prefer to explain it by the increased 

 food intake resulting from the stimulation of appetite. There are several 

 facts which favor the latter explanation. In the first place, the extent of 

 liver fattening in one series of tests by McHenry 856 was proportional to the 

 food intake. Moreover, thiamine does not cause fatty infiltration in rats 

 when the food intake is restricted to that consumed by the control rats on a 

 thiamine-free diet. Engel 822 reported substantially the same results. 



b'. Pyridoxine Fatty Livers: Engel 822 reported that fatty livers develop 

 in rats following a prolonged deficiency in pyridoxine. Halliday 858 noted a 

 similar effect, which she found was partially counteracted by choline and 

 was completely prevented by pyridoxine, given in the form of a liver ex- 

 tract. However, Gavin and McHenry 857 could detect no lipotropic action 

 on the part of crystalline pyridoxine. They suggest that the discrepancy 

 between their results and those of Halliday might be attributable to the 

 fact that they used a pure pyridoxine preparation, while Halliday em- 

 ployed a liver concentrate which may have contained other factors as 

 well. According to Engel, 822 fatty livers developing as a result of pyri- 

 doxine deficiency are counteracted by inositol. It is suggested by Peters and 

 Van Slyke 549 that the demand for choline and inositol is increased in pyri- 

 doxine deficiency. 



c'. Pantothenic Acid Fatty Livers : Scudi and Hamlin 859 reported that a 

 pantothenic acid deficiency in dogs results in a hypolipemia (cholesterol, 

 phospholipids, total lipids), which occurs concomitantly with a fatty in- 

 filtration of the liver. These results are in accord with the finding that 



854 E. \Y. McHenry, J. Physiol, 85, 343-349 (1935). 



886 E. W. McHenry, J. Physiol, 89, 287-295 (1937). 



887 G. Gavin and E. W. McHenry, J. Biol Chem., 132, 41-46 (1940). 

 858 N. Halliday, /. Nutrition, 16, 285-290 (1938). 



869 J. V. Scudi and M. Hamlin, J. Nutrition, U, 273-282 (1942). 



