380 V. BLOOD LIPIDS 



Table 4 

 Average Values op Unsaturated Fatty Acids in Blood Serum of Normal Chil- 

 dren and in Blood Serum and Blood Cells of Normal Adults 



Children Adults 



Fatty acid % of Mg. Plasma, e Cells, <* 



component total acids % b mg. % mg. % 



Oleic — 700 (250-950) 593 (370-720) 



Diene 30.9 62 70(15-115) 23.5(9-45) 



Triene 2.0 4 12(5-35) 3 



Tetraene 12.6 25 45(35-65) 74(54-91) 



The figures in parentheses represent the ranges in individual values. 



« H. F. Wiese, A. E. Hansen, and R. H. Gibbs, Federation Proc, 12, 433-434 (1953). 



b Based upon a value for total fatty acids of 200 milligram per cent. 



c A. Chevallier, S. Manuel, C. Burg, and J. Rouillard, Compt. rend. soc. biol., 144, 577- 

 578 (1950). The figures in parentheses represent the range. 



rf A. Chevallier, S. Manuel, and J. Rouillard, Compt. rend. soc. biol, 145, 924-927 

 (1951). 



b. Free Choline in Blood. Choline occurs in the free state in plasma. 

 Although earlier experiments suggested values of 2 to 20 /zg./ml., 189 Bligh, 190 

 using a new technic involving trichloracetic acid as a protein precipitant, 

 followed by ether extraction, acetylation of the choline, and its assay on the 

 rectus abdominis muscle of an eserinized frog, obtained constant values for 

 human plasma which were much lower (1-2 /ig./ml.). The level of choline 

 remained constant over a period of six months ; it was unaffected by food 

 or by exercise. 



The values for plasma choline in the dog and in the cat were found to be 

 similar to those in man. 190 Somewhat more variable results were exhibited 

 by the rabbit (1.2-5.2 /zg./ml.) together with a somewhat higher average 

 level. 190 In the case of the rat, 191 the normal level of free choline varied 

 between 1.3 and 1.9 jug./ml. However, when this species was maintained 

 for four months on a choline-deficient diet, the plasma level fell to between 

 0.6 and 1.1 /ig./ml. 



Under normal conditions, when choline is injected, it is rapidly removed 

 from the blood. According to Bligh, 192 the liver and kidneys are the or- 

 gans primarily concerned with the removal of choline since, after the 

 extirpation of these organs, the rate of disappearance of the base was con- 

 siderably diminished. However, some choline continued to disappear un- 

 der these conditions. This is taken to indicate that tissues other than the 

 liver and kidney can dispose of additional choline at a slow rate. 



189 H. D. Appleton, B. B. Levy, J. M. Steele, and B. B. Brodie, Federation Proc, 10, 

 157 (1951). 



m J. Bligh, /. Physiol, 117, 234-240 (1952). 

 191 J. Bligh, J. Physiol, 120, 440-444 (1953). 

 » 2 J. Bligh, J. Physiol, 120, 53-62 (1953). 



