THE FATTY ACIDS IN HUMAN BLOOD IN NORMAL 
AND PATHOLOGICAL CONDITIONS. 
| By FRANK A. CSONKA. 
(From the Laboratory of Dr. J. P. McKelvy, Pittsburgh.) 
(Received for publication, January 2, 1918.) 
INTRODUCTION. 
As has been shown in previous researches the fatty acids in 
human blood exist as glycerides, cholesterol esters, soaps, or as 
free acids; they are also represented as a radical of lecithin and 
the phosphatide groups. Their content varies in continued star- 
vation, fat absorption, anesthesia, certain pathological conditions, 
etc., as recently reported and confirmed in a series of papers by 
Bloor.t In normal individuals when care is taken to avoid the 
above conditions the amount of fatty acids in the blood is fairly 
constant. But little, if any attention has been given to the 
quality of the fatty acids, and especially to the proportion of 
saturated to unsaturated fatty acids as well as the degree of 
unsaturation. 
That there is a difference in the quality of the fatty acids of the 
whole human body is shown by the fact that the fats called in- 
terstitial, depot, and organ fats, each absorb iodine in different 
proportions, thus signifying that the unsaturated part of the 
fatty acids varies in the different tissues. Jaeckle? found an iodine 
number of 62 to 73 for human (interstitial) fat, and 70 to 80 
per cent of the fatty acids present as glycerides were oleic acid. 
Hartley’s? analysis of liver fat shows the presence of higher un- 
saturated fatty acids than oleic acid as indicated by the iodine 
number of 165 to 175. . 
1 Bloor, W. R., J. Biol. Chem., 1913-14, xvi, 517; 1914, xix, 1. Bloor, 
W. R., and MacPherson, D. J., tbid., 1917, xxxi, 79. Bloor, ibid., 1917. 
xxx1, 575. 
2 Jaeckle, H., Z. physiol. Chem., 1902, xxxvi, 53. 
3 Hartley, P., J. Phystol., 1909, xxxviil, 353. 
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