X. EFFECTS OF DEFICIENCY 71 



restoration of the decrease in choline-containing phospholipids caused by 

 choline deficiency in 2- to 3-month-old rats is particularly interesting l^e- 

 eause he was able to show that choline was largely effective in weanling 

 rats^^ and that this effect was not duplicated by aminoethanol, methionine, 

 serine, or glycine.®^ He has interpreted these data as evidence for the par- 

 ticipation with choline of a factor essential in phospholipid syntheses and 

 present in weanling rats to a greater extent than in older animals. Artom 

 and Fishman^^ have emphasized the fact that older rats were used in pre- 

 vious experiments which failed to demonstrate an effect of choline on total 

 liver phospholipids^*' ^*' ^* or an efTect on the choline content of livers,-^- ^* 

 whereas weanling rats were used in studies in which total phospholipids-" • ^^ 

 or total choline-containing phospholipids^^"^* were reported to be increased 

 by administration of choline. 



Brante^^ found a significant increase in liver cephalin in rats maintained 

 for several months on a choline-deficient, high fat diet. The level of 

 choline-containing phospholipids in the liver was the same in rats with and 

 without choline. No difference in the total choline content of liver and 

 kidneys of rats on control and low choline diets was noted by Kahane et 

 al.,''^ but the amount in the rest of the body was somewhat less in the 

 deficient group. Muscle creatine levels were not affected by an existing 

 deficiency of choline that permitted development of fatty livers.''^ 



Kensler et alP have made the very significant observation that the choline 

 oxidase activity of the liver and kidneys of young rats increases sharply 

 during the age period in which they are particularly susceptible to acute 

 choline deficiency. Of interest in this connection is the finding that the 

 severe renal lesions of choline deficiency were less frequently fatal in 20- 

 day-old rats than in those 21 to 27 days of age.* 



Chaikoff investigated the rate of phospholipid metabolism in rat liver 

 as measured by phosphorus turnover studies following the administration 

 of radioactive phosphorus (P*-). Choline and betaine^* and cystine and 

 methionines^ accelerated the turnover of phosphorus, the efTect of a single 



63 W. H. Fishman and C. Artom, /. Biol. Chem. 154, 109 (1944). 



«^ J. H. Channon and H. W. Wilkerson, Biochem. J. 28, 2026 (1934). 



" F. Cedrangolo and V. Baccari, Arch. sci. hiol. (Italy) 24, 311 (1938). 



«8 R. W. Engel, /. Biol. Chem. 144, 701 (1942). 



«^ D. Stetten, Jr., and G. F. Grail, J. Biol. Chem. 144, 175 (1942). 



«8 P. Handler and W. J. Dann, J. Biol. Chem. 146, 357 (1942). 



«» G. Brante, Acta Physiol. Scand. 6, 291 (1943). 



'" E. Kahane, J. L^vy, and O. Tanguy, Arch. sci. physiol. 4, 185 (1950). 



" E. Roberts and H. C. Eckstein, J. Biol. Chem. 154, 377 (1944). 



" C. J. Kensler, M. Rudden, E. Shapiro, and H. Langemann, Proc. Soc. Exptl. Biol. 



Med. 79, 39 (1952). 

 "I. Perlman and I. L. Chaikoff, J. Biol. Chem. 127, 211 (1939); 130, 593 (1939). 

 '* I. Perlman, N. Stillman, and I. L. Chaikoff, /. Biol. Chem. 133, 651 (1940). 



