438 V. BLOOD LIPIDS 



thyroidism. Only the ratio of cell cholesterol/cell P remained unchanged. 

 These variations occur because the cell lipid values remain relatively con- 

 stant in both hypothyroidism and hyperthyroidism. 



In addition to the interrelationship between the level of serum chole- 

 sterol and the activity of the thyroid, this gland also exerts some control 

 on the ratio of free to esterified cholesterol. Schwarz and Topper 509 found 

 that the ratio of free to total cholesterol was especially high in cases of 

 hypothyroidism (cretinism) in children. However, in adults with myx- 

 edema and other thyroid disturbances, a normal cholesterol partition has 

 been observed. 214 Foldes and Murphy 200 likewise reported that the ratios 

 of cholesterol ester: total cholesterol and of total cholesterol : P were sig- 

 nificantly increased in the plasma in hypofunction of this organ. The 

 latter effect is to be traced to the fact that, in the case of thyroid hypofunc- 

 tion, the increase in plasma cholesterol greatly exceeds that in the plasma 

 phospholipids. 



On the other hand, an increased activity of the thyroid gland results in 

 a reduction of the lipid components of the blood. Again, cholesterol is 

 the lipid component which shows the greatest regularity in response to the 

 increased amount of thyroid hormone. Low blood cholesterol and phos- 

 phatide values have been reported in patients having exophthalmic (or 

 toxic) goiter (also called Graves' or Basedow's disease) or other forms of 

 hyperthyroidism. 510 " 513 Moreover, an increased ratio of free cholesterol: 

 total cholesterol occurs in hyperthyroidism, in which case the esters are 

 decreased to a greater extent than is the free fraction. 502 However, 

 Foldes and Murphy 200 state that the changes in plasma lipids are less con- 

 sistent in hyperthyroidism than they are in hypothyroidism. 



"Antu," a-naphthylthiourea, which is an antithyroid drug, has been 

 shown to produce a reversible increase in serum cholesterol in thyroidec- 

 tomized dogs maintained on a dose of thyroid adequate to prevent thyroid 

 deficiency. 514 Fleischmann et a/. 514 suggest that this effect is at least 

 partly independent of its antithyroid action. 



b'. Serum Cholesterol and Basal Metabolism: Although the basal 

 metabolism has usually been considered to be the most satisfactory index 



509 H. Schwarz and A. Topper, /. Pediat., 3, 242-246 (1933). 



510 H. J. Bing and H. Heckscher, Biochem. Z., 158, 403-416 (1923). 

 811 L. M. Hurxthal, Arch. Internal Med., 52, 86-95 (1933). 



512 E. B. Man, E. F. Gildea, and J. P. Peters, /. Clin. Invest., 19, 43-59 (1940). 



513 E. G. Nicholls and W. A. Perlzweig, /. Clin. Invest., 5, 195-204 (1928). 



514 W. Fleischmann, J. L. Stubbs, and W. P. McShane, Proc. Soc. Exptl. Biol. Med. 

 70, 246-248 (1949). 



