364 VIII. THOLESTEROL AND RELATED STEROLS 



dose of cholesterol along with bile salts. Member and co-workers-^ were 

 able to induce the deposition of cholesterol in the aortas of rabbits only 

 when it was fed with bile salts. Siperstein and co-workers^'' also concluded, 

 more recently, that bile salts play an obligatory role in the passage of 

 cholesterol from the intestinal tract to the lymph. 



One of the most striking alterations in cholesterol absorption is produced 

 when phytosterols are present in the gut together with cholesterol. Peter- 

 son and associates^^'^- were the first to discover that, when soybean sterols 

 were fed to chicks together with cholesterol, hypercholesterolemia was pre- 

 vented. In a later report, ^^ it was further demonstrated that the deposi- 

 tion of cholesterol in the liver was also decreased. Alfin-Slater et al.^^ 

 reported that a similar decrease in the absorption of cholesterol, and in the 

 deposition of this sterol in the liver, occurred in the case of rats fed choles- 

 terol in conjunction with soy sterols. 



The reduced absorption produced by the soy sterols could not be as- 

 cribed solely to the high melting point of the cholesterol and soy sterol mix- 

 ture. In addition to soy sterols, mixed sitosterols, j8-sitosterol, stig- 

 masterol, and ergosterol, when fed singly, effected a similar inhibition of 

 cholesterol absorption. ^^ Cholestanol (dihydrocholesterol) produced the 

 same effect in cockerels,^* in rats,^^ and in mice.^^ Since esterification of 

 soy sterols inhibited their ability to prevent cholesterol absorption, ^^ it 

 was postulated that the unesterified soy sterols inhibit an enzyme system 

 concerned with cholesterol absorption, which may involve the esterification 

 of cholesterol.^^ 



Swell and co-workers^^ ascribed the beneficial effect of bile salts on the 



29 S. Member, M. Bruger, and E. Oppenheim, Arch. Pathol, 38, 210-214 (1944). 

 =^ M. D. Siperstein, I. L. Chaikoff, and W. O. Reinhardt, J. Biol. Chem., 198, 111-114 

 (1952). 



31 D. W. Peterson, Proc. Sac. Expil. Biol. Med., 78, 143-147 (1961). 



32 D. W. Peterson, C. W. Nichols, Jr., and E. A. Schneour, J. Nutrition, 47, 57-65 

 (1952). 



33 D. W. Peterson, E. A. Schneour, N. F. Peek, and H. W. Gaffey, /. Nutrition, 50, 

 191-201(1953). 



3^ R. B. Alfin-Slater, A. F. Wells, L. Aftergood, and H. J. Deuel, Jr., Circulation 

 Research, 2, 471-475 (1954). 



36 M. D. Siperstein, C. W. Nichols, Jr., and I. L. Chaikoff, Circulation, 7, 37-41 

 (1953). 



36 R. H. Rosenman, S. O. Byers, and M. Friedman, Circulation Research, 2, 45-47 

 (1954). 



37 W. T. Beher and W. L. Anthony, /. Nutrition, 62, 519-524 (1954). 



38 H. H. Hernandez, D. W. Peterson, I. L. Chaikoff, and W. G. Dauben, Proc. Soc. 

 Exptl. Biol. Med., 83, 498-499 (1953). 



39 L. Swell, D. F. Fhck, H. Field, Jr., and C. R. Treadwell, Proc. Soc. Exptl. Biol. 

 Med., 84, 428-431 (1953). 



i 



