LIPIDS PRESENT IN LIVER 711 



tion, Schmidt et aU 9 proved that this component accounted for more than 

 one-half of the phospholipid choline in fresh lamb liver. On the other hand, 

 only negligible amounts of water-soluble choline compounds occurred in the 

 fresh livers obtained from weanling or adult rats. These results indicate 

 that glycerylphosphorylcholine is an intermediate in the metabolism of 

 lecithin. The analyses of the classical phospholipids in the liver of man 

 are included in Table 1. 



Table 1 



The Phospholipid Content of the Liver of Man and of Various Other Animals, 



Expressed as Per Cent of Moist Organ Weight 



Acetone- 

 Source of Total Sphingo- soluble 

 tissue phospholipid Lecithin Cephalin myelin fraction 



Human" 2.94 6 1.44* 1.19* 0.11 6 



Beef" 3.08 1.56 1.50 0.90 



Horse* 3.7 



Guinea pig d 2.9 



Rat<* 2.9 



Pigeon** 2.9 



Frog* 3.1 



Carp* 2.5 



Dogfish* 1.7 



° S. J. Thannhauser, J. Benotti, A. Walcott, and H. Reinstein, J. Biol. Chem., 129, 

 717-719 (1939). 



6 Calculated from dry weight on basis of 70% water content. 



c W. R. Bloor, J. Biol. Chem., 80, 443-454 (1928). 



d M. Javillier, A. Cremieu, and H. Hinglais, Bull. soc. chim. biol., 10, 327-337 (1928). 

 Figures recalculated by W. R. Bloor, Biochemistry of the Fatty Acids, Reinhold, New 

 York, 1943, p. 199. 



c. Plasmalogens in the Liver. In addition to the usual phosphatides 

 shown to be present in the liver, Klenk and Friedrichs 40 have demonstrated 

 the presence of plasmalogens in this organ. In contradistinction to the 

 lipids of the heart, pancreas, kidney, and adrenal glands, in which the plas- 

 malogen content is determined directly, and can then be confirmed by the 

 isolation of the dimethylacetal fraction, the plasmalogen in the liver has a 

 dimethylacetal value corresponding to 64% of that determined directly. 

 This discrepancy is probably to be ascribed to an inaccuracy inherent in the 

 method when small amounts of plasmalogen are present. In fatty livers 



39 G. Schmidt, L. Hecht, P. Fallot, L. Greenbaum, and S. J. Thannhauser, J. Biol. 

 Chem., 197, 601-609 (1952). 



i0 E. Klenk and E. Friedrichs, Z. physiol. Chem., 290, 169-171 (1952). 



