Chapter 5 

 CHOLINE 



Page 



I. Nomenclature and Formula 2 



II. Chemistry 2 



A. Isolation 2 



B. Physical and Chemical Properties 10 



C. Constitution and Synthesis 10 



III. Industrial Preparation 14 



(included in part in Section II. C) 



IV. Biochemical Systems 15 



A. Enzymes and Coenzymes 15 



B. Choline Acetylase and Acetylcholinesterase 15 



C. Mechanism of Action of Choline 18 



1. Derivatives of Phosphorylcholine 18 



2. Choline and Transmethylation 19 



3. Nature of Methyl Donors in Transmethylation 24 



4. Methyl Acceptors, Transmethylation, and Formate-to-Methyl Syn- 

 thesis 26 



5. Choline Oxidase and the Choline-Betaine-Glycine Relationship . 33 



6. Oxidation of Methyl Carbons 43 



7. Other Aspects of Methyl Transfer and Oxidation 44 



V. Specificity of Action 45 



VI. Biogenesis 49 



VII. Estimation 52 



A. Chemical Procedures 52 



B. Microbiological Procedures 55 



C. Biological Assays 57 



D. Physical Estimation 57 



VIII. Standardization of Activity 58 



IX. Occurrence 58 



X. Effects of Deficiency 62 



A. General Manifestations 62 



B. Rat 63 



1. Renal Lesion 63 



2. Fatty Liver 67 



3. Effect of Sulfur Amino Acids 76 



4. Effect of Other Nutrients 80 



5. Other Effects 88 



6. Fate of Choline 92 



C. Avian Species 93 



D. Dog 97 



E. Other Species 101 



F. Man 104 



1 



