406 V. BLOOD LIPIDS 



phospholipid, and neutral fat, in individual organs and in the carcass, 

 occurred concomitantly with the hyperlipemia. 



According to Chaikoff and Entenman 298 the values of blood cholesterol, 

 phospholipids, and fatty acids in the painted terrapin (Chryse?nys picta 

 bellii) and the fresh-water scribe turtle (Pseudemys scripta) are related to 

 ovarian activity, as is the case with the fowl. These fractions were aug- 

 mented during ovarian function. 



g. The Effect of Pregnancy. Many studies have been made of the 

 effect of pregnancy on the level of blood lipids in human subjects. Her- 

 mann and Neumann 299 reported an average increase in the total lipids 

 from 590 to 780 milligram per cent; the increases were largely in neutral 

 fat and cholesterol esters. Some workers have noted slight increases in 

 fatty acids, 300-302 and also in phospholipids, 300 ' 30U03 as a result of pregnancy. 



Blood cholesterol exhibits the most pronounced changes of any of the 

 lipids during pregnancy. There is general agreement that the cholesterol 

 fraction of the blood increases markedly in this condition. 299-301 - 304 - 307 

 The increase in cholesterol begins after the second month and continues up 

 to the thirtieth week, after which it again decreases until delivery. 304 The 

 maximum values are 50 to 100% higher than the normal values for non- 

 pregnant women. 



The increase in cholesterol concentration during pregnancy may be as- 

 sociated with a change in the ratio of free to esterified cholesterol. Accord- 

 ing to Bloor and Knudson, 216 the ester fraction, chiefly, is increased; Boyd 301 

 found a normal partition of cholesterol between the free and esterified 

 forms. On the other hand, Gardner and Gainsborough 304 reported that 

 free cholesterol alone is increased, while the ester fraction may even show a 

 decrease. In these tests, the ratio of free to total cholesterol reached a 

 value as high as 0.90. The discrepancies reported by the several investi- 

 gators might be due to their failure to recognize that the cholesterol may 

 be bound with plasma protein. Eufinger 308 reported that the fraction of 

 cholesterol in this combination is considerably increased toward the end of 



298 1. L. Chaikoff and C. Entenman, J. Biol. Chem., 166, 683-689 (1946). 



299 E. Hermann and J. Neumann, Biochem. Z., 43, 47-55 (1912). 



300 C. Fahrig and L. Wacker, Klin. Wochschr., 11, 886-891 (1932). 



301 E. M. Boyd, /. Clin. Invest, 13, 347-363 (1934). 



302 H. Knauer, Jahrb. Kinderheilk., Abhandl., 22, 1-164 (1928). 



303 B. L. Oser and W. G. Karr, Arch. Internal Med., 36, 507-515 (1925). 



304 J. A. Gardner and H. Gainsborough, Lancet, 1929, 1, 603-606. 

 306 E. E. Pribram, Arch. Gynakol, 119, 57-68 (1923). 



306 W. Stepp, Munch, med. Wochschr., 65, 781-785 (1918). 



307 M. Tyler and F. P. Underhill, /. Biol. Chem., 66, 1-14 (1925). 



308 H. Eufinger, Arch. Gynakol, 133, 475-489 (1928). 



