402 VIII. CHOLESTEROL AND RELATED STEROLS 



(S) Experimental Evidence of 

 Cholesterol Destruction in the Tissues 



The earlier proof that cholesterol is destroyed by tissues was generally 

 based upon the balance type of test. Dam-^^ reported that the disappear- 

 ance of cholesterol in chicks was greater than could be accounted for by 

 excretion. Page and Menschick^^^ observed that cholesterol fed to rabbits 

 was deposited in all their tissues with the exception of the brain. However, 

 after accounting for the cholesterol deposited in the tissues and that ex- 

 creted, they demonstrated that more than one gram was destroyed per 

 week. Bloch et al.^^^ showed that, in addition to the brain, the spinal cord 

 also fails to take up injected cholesterol. Menschick and Page-^^ demon- 

 strated the destruction of cholesterol by the tissues of cats. The compound 

 was found to be stored in all the tissues except the brain. The liver con- 

 tent was much greater than was the case with rabbits, that of the other 

 tissues somewhat less.-^^ Schonheimer^"" presented evidence of cholesterol 

 destruction in man on the basis of study of a case of hypercholesterolemia. 



Dirscherl and Traut^"^ reported that a negative cholesterol balance obtains 

 in mice. This is interpreted as evidence that decomposition of choles- 

 terol takes place. More exact proof of the synthesis and desti-uction of 

 cholesterol has been adduced by Schoenheimer and Breusch,'''* who em- 

 poyled mice as the experimental animals; it was found that mice could de- 

 stroy five times their total cholesterol content per month. It was pos- 

 tulated that a dynamic state of equilibrium exists between the synthesis 

 and the destruction of cholesterol. The total amount present in the animal 

 body at any one time depends upon the balance between these two processes 

 The rate of destruction is believed to be accelerated when the dietary choles- 

 terol is increased. -^^ 



a. The Destruction of Cholesterol by Bacteria. Wainfan et al.^- re- 

 ported that destruction of cholesterol by bacteria probably occurs in the 

 gastrointestinal tract. Thus, when feces or intestinal contents of choles- 

 terol-fed rats were incubated with cholesterol, a significant decrease in 

 the total cholesterol content resulted. Two species of bacteria isolated in 

 pure culture from the feces of cholesterol-fed rats, which were active in 



296 H. Dam, Biochem. Z., 232, 269-273 (1931). 



2" I. H. Page and W. Menschick, J. Biol. Chem., 97, 359-368 (1932). 



298 K. Bloch, B. N. Berg, and D. Rittenberg, /. Biol. Chem., 149, 511-517 (1943). 



2" W. Menschick and I. H. Page, Z. phijsiol. Chem., 218, 95-103 (1933). 



300 R. Schonheimer, Z. klin. Med., 123, 749-763 (1933). 



301 W. Dirscherl and H. Traut, Z. physiol. Chem., 262, 61-86 (1940). 



302 E. Wainfan, G. Henkin, S. C. Rittenberg, and W. Marx, J. Biol. Chem., 207, 843- 

 849 (1954). 



