QUANTITATIVE RELATIONS OF BLOOD LIPIDS 



389 



at cholesterol levels higher than 100 milligram per cent. 215 The formula is 

 as follows : 



lipid P (mg. %) = 0.0294 cholesterol (mg. %) + (3.62 ± 1.04) 

 d. Cholesterol Ester: Total Cholesterol Ratio. A number of workers 

 have established the fact that the ratio of cholesterol esters to total choles- 



"0 10 20 30 00 50 00 70 80 90 



Free Cholesterol : Total cholesrerof 



Fig. 2. The interrelations of the serum lipids. The limits of the ratios in nor- 

 mal subjects lie between the two vertical and the two horizontal lines. 215 



terol is a rather precise biological constant. Bloor and Knudson 216 first 

 reported that approximately 60% of the total cholesterol was esterified. 

 However, it now appears that this value is too low, as Boyd 186 obtained a 

 figure of 70% in the case of young women, and Sperry, 217 in an extensive 

 study which included 91 adults, reported an average of 73 ± 1.4%. Sperry 

 states that the constancy of this ratio is much greater than is ordinarily 

 supposed. Peters and Man 213 and Brun 218 confirmed the results of Sperry. 



215 E. B. Man, B. L. Kartin, S. H. Durlacher, and J. P. Peters, J. Clin. Invest., 24, 

 623-643(1945). 



216 W. R. Bloor and A. Knudson, /. Biol. Che?n., 27, 107-112 (1916); 29, 1-13 (1917). 



217 W. M. Sperry, /. Biol. Chem., 114, 125-133 (1936). 



213 G. Brun, Changes in the Lipide Contents of Serum in Patients with Manic-depressive 

 Psychosis, H. K. Lewis, London, 1940. 



