408 



VIII. CHOLESTEROL AND RELATED STEROLS 



and to purify the two major corticosteroids synthesized by the adrenals. 

 These could be synthesized either from acetate or from cholesterol itself. 



In the experiments of Marx et al.,^^^ it was found that the thyrotoxicosis 

 produced in rats by the feeding of high levels of the thyroid hormone could 

 be markedly alleviated, the survival time prolonged, and in most cases the 

 weight loss could be prevented by adding one per cent of cholesterol and 



Fig. 3. The effect of dietary cholesterol on the body weight of rats fed toxic doses of 



thyroid hormone. ^^ 



0.5% of bile salts to the experimental diet. Thus, in nine-month-old rats, 

 the average survival time was increased from 23 days to 55+ days simply 

 by the expedient of adding the cholesterol and bile salts to the diet. In a 

 second test, the comparative mean survival time was 86 ± 3.9 days for the 

 control group, and greater than 111 ± 5.4 days for the cholesterol-fed 

 group. The effect of the thyroid hormone on the body weight under these 

 different dietary conditions is shown in Figure 3. 



330 W. Marx, E. R. Meserve, and H. J. Deuel, Jr., Proc. Soc. Exptl. Biol. Med., 67, 

 385-387 (1948). 



