FACTORS ALTERING CONCENTRATION OF BLOOD LIPIDS 419 



hypercholesterolemia rapidly developed in these animals when they were 

 placed on a high cholesterol diet. 



(b) Hypercholesterolemia in Animals Other Than Man. Rats and rabbits 

 differ from man in their reaction to dietary cholesterol. The feeding of an 

 excess of cholesterol in the diet brings about a hypercholesterolemia in 

 rats, 202 as well as fatty livers. 377-380 When cholesterol-containing diets 

 are fed to rabbits with bile salts, not only hypercholesterolemia, 380 but also 

 atherosclerosis occurs. 381 - 382 Tn the case of guinea pigs, hypercholesterol- 

 emia follows the administration of the sterol, and a fatty infiltration also 

 occurs in the liver. 379 - 383 Knudson 384 reported an increase in free choles- 

 terol in both the blood plasma and the corpuscles, when either free or 

 esterified cholesterol was fed to dogs. However, no change in cholesterol 

 esters resulted. Although Bloor 7 believes that cholesterol is not appre- 

 ciably absorbed from the intestine in the absence of fat, Domosi and 

 Egyed 385 showed that cholesterol was readily absorbed from the alimentary 

 tract if administered in the form of an amorphous suspension in water. 

 Blood cholesterol was shown to rise in four to five days from about 80 to 

 300-400 mg./lOO ml, and in three to four weeks to 1300-1800 mg./lOO 

 ml., concomitant with the development of atheroma in the aorta and pul- 

 monary arteries. These results have been confirmed by Popjak 386 ; the 

 latter investigator notes that amorphous cholesterol is much more effective 

 in increasing blood cholesterol than is cholesterol dissolved in fat. 



(c) The Effect of Ingested Cholesterol on Other Blood Lipids. There is 

 considerable evidence that lipid components other than cholesterol in the 

 blood may be altered by the ingestion of cholestercl-containing diets. 

 Page and Bernhard 387 noted that, when cholesterol in olive oil was fed to 

 rabbits, the phospholipids were increased in the plasma. Weinhouse and 

 Hirsch 388 confirmed this finding and noted that the natural fat and chole- 

 sterol fractions of the blood were likewise increased when cholesterol- 



377 C. H. Best, H. J. Channon, and J. H. Ridout, /. Physiol, 81, 409-421 (1934). 



378 C. H. Best and J. H. Ridout, J. Physiol, 78, 415-418 (1933). 



379 R. P. Cook, Biochem. J., 80, 1630-1636 (1936). 



380 L. Swell and D. F. Flick, Am. J. Physiol, 174, 51-53 (1953). 



381 K. B. Turner, J. Exptl. Med., 58, 115-125 (1933). 



382 K B. Turner and E. H. Bidwell, J. Exptl Med., 62, 721-732 (1935). 



383 R. Okey, Proc. Soc. Exptl Biol. Med., 51, 349-350 (1942). 



384 A. Knudson, J. Biol. Chem., 45, 255-262 (1921). 



385 P. Domosi and M. Egyed, Magtjar Orvosi Arch., 40, 242 (1939); cited by G. Popjak, 

 Biochem. J., 40, 608-621 (1946), p. 608. 



386 G. Popjak, Biochem. J., 40, 608-621 (1946). 



387 I. H. Page and W. G. Bernhard, Arch. Pathol, 19, 530-536 (1935). 



388 S. Weinhouse and E. F. Hirsch, Arch. Pathol, SO, 856-867 (1940). 



