LIPID STORAGE UNDER ABNORMAL CONDITIONS 671 



basis of its choline content. Following this work, Dragstedt and his 

 co-workers 786 - 787 arrived at similar conclusions; they believed that 1 g. of 

 choline was required daily to prevent fatty livers in depancreatized dogs, 

 while the amount administered in their pancreatic preparation amounted 

 to only 60 mg. These workers coined the term "lipocaic" to designate the 

 component which prevented the development of fatty livers. It was 

 considered to be a hormone, found only in the pancreas, and concerned 

 exclusively with the transport and utilization of fat. Further support for 

 the hypothesis that another factor, in addition to choline, is involved in con- 

 trolling fatty livers came from the experiments of Kaplan and Chaikoff. 788-790 

 These workers confirmed the fact that liver fat was reduced and blood fat 

 increased when raw pancreas was given to depancreatized dogs. These two 

 effects could not be produced by means of choline alone or with choline plus 

 autoclaved pancreas. On the basis of this work it was suggested that pan- 

 creas contains two factors active in lipid metabolism, namely, a heat-labile 

 fraction controlling blood lipids, and a heat-stable component (probably 

 choline) which controls the deposition of lipids in the liver. These workers 

 recognized that the factors controlling fatty livers in depancreatized dogs 

 and in rats on a low-protein, high-fat diet may be entirely different, and 

 that the conclusions obtained in one case may not be applicable to the 

 other. The numerous controversies in the interpretation of the results in 

 this field are to a considerable degree due to the failure to recognize these 

 differences. 



b'. Experimental Evidence of Lipocaic Activity toward Fatty Livers 

 Resulting from Choline Deficiency: Shortly after the report of Dragstedt 

 on lipocaic, a number of workers attempted to investigate the lipotropic 

 action of this compound on rats with fatty livers produced by a low choline 

 regimen. Best and Ridout 791 were the first to report that lipocaic had no 

 specific activity in removing liver fat other than that attributable to its 

 choline and protein content. Aylward and Holt, 792 MacKay and Barnes, 793 

 and Wick and Laurence 794 reached essentially similar conclusions when the 



786 J. Van Prohaska, L. R. Dragstedt, and H. P. Harms, Am. J. Physiol, 117, 166-174 

 (1936). 



787 L. R. Dragstedt, J. Van Prohaska, and H. P. Harms, Am. J. Physiol, 117, 175-181 

 (1936). 



788 A. Kaplan and I. L. Chaikoff, Proc. Soc. Expll. Biol. Med., 34, 606-607 (1936). 



789 A. Kaplan and I. L. Chaikoff, J. Biol Chem., 119, 435-449 (1937). 



790 A. Kaplan and I. L. Chaikoff, J. Biol. Chem., 120, 647-657 (1937). 



791 C. H. Best and J. H. Ridout, Am. J. Physiol, 122, 67-72 (1938). 



792 F. X. Aylward and L. E. Holt, Jr., J. Biol. Chem., 121, 61-69 (1937). 



793 E. M. MacKay and R. H. Barnes, Proc. Soc. Exptl. Biol. Med., 38, 410-414 (1938). 



794 A. N. Wick and E. Laurence, Arch. Biochem., 20, 113-117 (1949). 



