CHOLINE 



chloride to the diet produced no toxic effect in 6o-g. rats, but lo % 

 stopped growth and intermediate amounts retarded growth. ^ No 

 pathological changes were observed at autopsy. The addition of i, 2 

 and 4 % of choline to the diet reduced the growth rate of chicks by 

 12, 13-8 and 23-8 % respectively, but no other toxic effects were 

 observed. 3 The administration of 400 mg. of choline chloride per kg. 

 of bodyw-eight to dogs with experimentally induced fatty livers for 

 more than three weeks did not produce any adverse effects * but, 

 according to J. E. Davis, ^ prolonged administration of choline to dogs 

 caused a fall in the red blood cells. He attributed this to the vaso- 

 dilator effect of choline and the consequent increased supply of blood 

 and oxygen to the bone marrow, since atropine, which blocks the 

 vasodilator action of choline but not its lipotropic effect, restored the 

 erythrocytes to normal. G. E. Cartwright and M. M. Wintrobe ® 

 failed to observe any effect of choline on the red blood cells in man. 



Choline has a vasodilator effect, but this is very much less marked 

 than that of acetyl choline.^ 



References to Section 10 



1. M. W. Neuman and H. C. Hodge, Pyoc. Soc. Exp. Biol. Med., 



1945. 58, 87. 



2. H. C. Hodge, ibid., 212. 



3. V. H. Melass, P. B. Pearson and R. M. Sherwood, ibid., 1946, 62, 



174. 



4. A. Kaplan and I. L. Chaikoff, /. Biol. Chem., 1937, 120, 647. 



5. J. E. Davis, Amer. J. Physiol., 1944, 142, 402; Science, 1947, 105, 43. 



6. G. E. Cartwright and M. M. Wintrobe, /. Amer. Med. Assoc, 1945. 



127, 911. 



7. F. W. Mott and W. D. Halliburton, Proc. Roy. Soc, 1899, 65, 91 ; 



A. Lohmann, Arch. Physiol., 1906, 118, 215 ; A. Desgrez and 

 J. Chevalier, Compt. rend., 1908, 146, 89 ; J. Gautrelet, ibid., 

 1909, 148, 995- 



II. CHOLINE IN THE NUTRITION OF MICRO- 

 ORGANISMS 



Comparatively few organisms have been discovered that require 

 choline for growth. A Type HI pneumococcus was reported as being 

 unable to grow in the absence of choline ^ and Clostridium hotulinum 

 was found to require choline. ^ 



Of thirty-five compounds related to choline only one, aminoethanol, 

 was able to support the growth of pneumococcus in the absence of 

 choline ; ^ this micro-organism is able, apparently, to convert amino- 

 ethanol into choline. 



596 



