LIPID STORAGE UNDER ABNORMAL CONDITIONS 673 



cumstance which argues against this concept is the time required to produce 

 a fatty liver deficiency resulting from the lack of lipocaic. Hormones or- 

 dinarily act with dispatch. Secretin results in the production of pancre- 

 atic juice within thirty seconds after its injection. Insulin has an almost 

 immediate effect in reducing blood sugar. Fat accumulates in the liver of 

 rats, following the administration of a choline-low diet, within twenty-four 

 hours after the initiation of the diet. 664 However, it requires weeks or even 

 months for fatty livers to develop in the absence of lipocaic. The pro- 

 longed time required for lipocaic deficiency to become manifest would lead 

 one to class it as a dietary deficiency. 



Another result, which is opposed to the view that lipocaic is a hormone, is 

 the apparently wide distribution of this substance in different tissues. A 

 hormone is characterized by the fact that it is produced and concentrated 

 in a single endocrine organ. On the other hand, Gavin and McHenry, 802 

 using extracts of liver, kidney, muscle, wheat germ, and rice polishings pre- 

 pared by the method described by Dragstedt et al. for the preparation of 

 lipocaic, were able to demonstrate that these extracts, as well as pancreatic 

 extract, prevented the biotin type of fatty livers. However, it is admitted 

 by McHenry and Patterson 547 that this proof is not decisive, since tests 

 were not made with other types of fatty livers in rats, or on the fatty livers 

 of depancreatized dogs. However, the results argue against the specific 

 nature of the lipotropic substance, which would be necessary if it were to be 

 classed as a hormone. 



e'. Lipocaic as an Enzyme: The first suggestion that the effect of pan- 

 creas on liver lipids might be enzymatic in nature was the demonstration 

 that ligation of the pancreatic duct produced fatty livers in a manner anal- 

 ogous to that following removal of the gland. Thus, Ralli et aZ. 558 noted 

 that ligation of the pancreatic duct (and hence the removal of pancreatic 

 juice from the lumen of the gut) resulted in fatty livers. Moreover, 

 Montgomery, Chaikoff, and their associates, 799,800 reported a number of ex- 

 periments which indicate that the feeding of pancreatic juice is just as ef- 

 fective in reducing the fat in the fatty livers of depancreatized dogs as is 

 raw pancreas. In later work 803 it was reported that as small an amount as 5 

 mg. of trypsin in each lean meat meal fed to insulin-treated, depancreatized 

 dogs was sufficient to prevent the development of fatty livers. Trypsin is 

 thus identified as a possible intrinsic anti-fatty-liver factor in the dog. In 

 addition to trypsin, other proteolytic enzymes, such as chymotrypsin, car- 



802 G. Gavin and E. W. McHenry, J. Biol. Chem., 139, 485 (1941). 



803 M. L. Montgomery, C. Entenman, I. L. Chaikoff, and H. Feinberg, J. Biol. Chem., 

 185, 307-310 (1950). 



