92 CHOLINE 



been confirmed.-^* Sure concluded that choline was indispensable for lacta- 

 tion and growth in rats.-*^ Rustiness of the hair was produced by omission 

 of either choline or pantothenic acid from the diet.-^^ On the other hand, 

 so-called bronzing of the hair in young rats was ascribed to the choline 

 intake and was prevented by dietary yeast or by the presence of dextrin 

 in the ration. -^^ Dietary choline prevented toxic effects of excess 

 methionine.'^^ 



6. Fate of Choline 



The data of Luecke and Pearson may be cited as confirmatory evidence 

 of the conclusion of earlier investigators^*^' -^'' that administered choline 

 and betaine disappear rapidly .^^^ Of 10 to 20 g. of choline administered to 

 sheep, only 1 % was recovered in the urine during a 48-hour period, an equal 

 amount was found in the feces, and no accumulation was detected in liver, 

 kidney, or blood. Similar results were found in dogs. No excretion of betaine 

 followed the ingestion of 20 g. of this substance in a sheep. Davies showed 

 that 14 to 43 % of the nitrogen of choline and of betaine in the diet of cows 

 was excreted as trimethylamine oxide .-^^ Small amounts of trimethylamine 

 and traces of the di- and monomethylamines were found. Davies noted 

 that cattle fed sugar beet by-products consumed as much as 100 g. of betaine 

 daily without the excretion of detectable amounts. It is probable that tri- 

 methylamine is the result of the action of intestinal microorganisms on 

 choline or betaine,-^^ inasmuch as many organisms are known to have this 

 effect.2^*-"^^ Whether or not animal tissues also form trimethylamine needs 

 further study. This substance was identified as a product of in vitro me- 

 tabolism in liver slices, but the sterility of the system was not dem- 

 onstrated .^^^ The rapid disappearance of repeated sublethal doses of choline 

 in rats and mice was reported by Kahane et alr^^ 



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