96 CHOLINE 



tion of mono-and dimethylaminoethanol in chicks fed betaine did not occur 

 unless Bi2 was present. ^^^ 



Contrary to the results of others, McGinnis et at. found methionine and 

 betaine effective antiperotic agents in certain diets, but this result was not 

 obtained if more highly purified diets were employed. ^^"^ In later experi- 

 ments, Gillis and Norris observed the same stimulation of growth by betaine 

 and by choline if the B12 stores were normal but inferior growth with choline 

 if the B12 stores were low.^^^ The absence of an effect of B12 on the utilization 

 of betaine was also demonstrated by the equal stimulation of growth of 

 Bi2-deficient chicks by methionine and by homocystine plus betaine. ^^^ 



Thus, the interrelationships of choline, betaine, and B12 in the chick are 

 not clear. GilUs and Norris do not believe that B12 is concerned with the 

 conversion of choline to betaine by choline oxidase because no evidence was 

 found of a decreased content of this enzyme in the livers of Bi2-deficient 

 chicks. ^'^ They concluded that at least one mechanism by which the chick 

 uses choline is impaired by a deficiency of B12 whereas betaine remains effec- 

 tive under the same conditions. 



The depression of choline oxidase in the bone marrow^"" and liver^^^ of 

 chicks deficient in folic acid and the reduction of this enzyme in the bone 

 marrow of hens exposed to x-irradiation^^^ have been mentioned previously. 

 Choline oxidase in the livers of chick embryos was decreased by folic acid 

 fed to the mother hen whereas much less reduction occurred if folic acid 

 was injected directly into the egg during or prior to incubation.^^^ Con- 

 flicting evidence has been presented regarding the need of dietary choline 

 by pullets and older hens. Abbott and DeMasters reported increased egg 

 production with dietary choline,^^^ but no significant differences in this 

 respect or in hatchability, fertility, or body weight were noted by Lucas 

 et al.^^'' Hatchability was not improved in the study of Bethke ei alP^ 

 Ringrose and Davis likewise found no change in egg production with added 

 choline. It was noted in the latter experiments that twice as much choline 

 was present in the egg yolks as was present in the diet.^^^ Total blood choles- 

 terol and cholesterol ester and the levels of these components of aorta, heart 



330 J. McGinnis, L. C. Norris, and G. F. Heuser, Proc. Soc. Exptl. Biol. Med. 56, 197 

 (1944). 



331 M. B. Gillis and L. C. Norris, /. Nutrition 43, 295 (1951). 



332 M. B. Gillis and L. C. Norris, Proc. Soc. Exptl. Biol. Med. 77, 13 (1951). 



333 J. S. Dinning, C. K. Keith, and P. L. Day, J. Biol. Chem. 189, 515 (1951). 



33* J. S. Dinning, I. Meschan, C. K. Keith, and P. L. Day, Proc. Soc. Exptl. Biol. 

 Med.li, 776 (1950). 



335 J. N. Williams, Jr., M. L. Sunde, W. W. Cravens, and C. A. Elvehjem, J. Biol. 

 Chem. 185, 895 (1950). 



336 O. D. Abbott and C. U. DeMasters, /. Nutrition 19, 47 (1940). 



337 H. L. Lucas, L. C. Norris, and G. F. Heuser, Poultry Sci. 25, 373 (1946). 



338 R. M. Bethke, D. C. Kennard, and V. D. Chamberlin, PouUrij Sci. 25, 579 (1946). 



339 R. C. Ringrose and H. A. Davis, Poultrrj Sci. 25, 646 (1946). 



