90 CHOLINE 



and combined choline,^^" and increased concentrations were also found in 

 transplanted epidermal carcinomas in mice.-^^ In the latter studies the in- 

 crease appeared to be due to phospholipids. 



The passage of fat through the intestinal mucosa during absorption was 

 accelerated by feeding choline with the fat, according to Frazer.^^'- Tidwell 

 presented evidence for the view that choline played a chemical role and did 

 not influence absorption because of an effect on emulsification.^^^ This view 

 is in line with the favorable influence of choline on phospholipid 

 synthesis.^*' ^"' ^^* Directly or indirectly, choline affected the intestinal ab- 

 sorption and distribution of vitamin A. Rats on a choline-deficient diet 

 containing liberal amounts of carotene developed fatty livers poor in vi- 

 tamin A although the kidneys were rich in the vitamin.^^^ The addition of 

 choline to solutions of vitamin A in olive oil yielded higher levels of liver 

 vitamin A after oral administration in normal rats.-^® 



Choline and pyridoxine were protective against the hyperplasia and ul- 

 cerations that appeared in the forestomach of rats fed a diet containing 

 white flour and cystine as the sources of nitrogen.^^^ Sharpless suggested 

 that regurgitated bile might be an important cause of the lesions and that 

 choline prevented regurgitation by stimulation of the smooth muscle of 

 the intestine.-®^ 



Abdon and Borglin reported that an impairment of oxidative metabolism 

 was an early symptom of choline deficiency in rats. The in vitro oxygen con- 

 sumption of minced muscle tissue from deficient rats was not increased by 

 choline or methionine but was returned to a normal value by an acetone- 

 insoluble preparation of splenic tissue .^^^ Olson and Deane noted decreased 

 respiration of kidney slices during the acute phase of hemorrhagic degener- 

 ation.^® 



Dinning et al. demonstrated that leucopenia was present in rats main- 

 tained for 65 days on a diet low in methionine (0.27 %) and in B^ and con- 

 taining a moderate level of choline (0.1 %). The interference with leucocyte 

 formation was prevented by supplemental methionine with or without folic 



''60 D. Vincent, S. Daum, and M. Bouchet, Trav. membres soc. chim. biol. 23, 1363 



(1941). 

 2«i M. G. Ritchey, L. F. Wicks, and E. L. Tatum, J. Biol. Chem. 171, 51 (1947). 



262 A. C. Frazer, Nature 157, 414 (1946). 



263 H. C. Tidwell, J. Biol. Chem. 182, 405 (1950). 



264 H. D. Friedlander, I. L. Chaikoff, and C. Entenman, J. Biol. Chem. 158, 231 (1945). 



265 H. Popper and H. Chinn, Proc. Soc. Expil. Biol. Med. 49, 202 (1942). 



266 A. Pederzini, Boll. soc. ital. biol. sper. 24, 1146 (1948). 



26T G. R. Sharpless, Proc. Soc. Exptl. Biol. Med. 45, 487 (1940). 



268 G. R. Sharpless and M. Sabol, J. Nutrition 25, 113 (1943). 



269 N. O. Abdon and N. E. Borglin, Nature 158, 793 (1946); 159, 272 (1947); ^cia Phar- 

 macol. Toxicol. 3, 73 (1947). 



