Observations of Cholesterol-Fed Guinea Pigs. 6i 



anisotropic fat occurs, and that such injury is produced by oil. 

 If such injurious effect is exercised by cotton seed oil, it is also 

 exercised by various oils which have been used as vehicles in the 

 administration of cholesterol, and also by some substance in egg 

 yolk other than cholesterol. A rabbit may moreover be fed large 

 daily doses of cotton seed oil over a long period without the 

 production of any demonstrable lesion of the vessels. It would 

 therefore seem more probable that the importance of the fat lies 

 in the fact that it supplies to the diet of these animals, normally 

 low in fat, an essential factor for the formation of esters, and thus 

 enables the absorption of cholesterol in large amounts, and 

 possibly also that it facilitates the formation of some compound 

 with cholesterol, in the process of metabolism, which is toxic to 

 the vessels. 



Anitschkow and Aschoff believe that the production of ather- 

 oma in cholesterol-fed rabbits is aided by raising the blood pressure 

 by mechanical or chemical means. Since the production of cho- 

 lesterol atheroma in rabbits is so rapid without resort to artificial 

 means of changing the blood pressure, the guinea pig seemed a 

 more suitable animal for testing this theory. A guinea pig re- 

 ceived daily doses of cholesterol in oil, 12 gm. in all, for a period 

 of 82 days. During the last 32 days of the feeding he was sus- 

 pended head down for 15 to 40 minutes daily. Another received 

 4.7 g. in 44 days and was suspended 20 to 40 minutes daily for the 

 last 38 days. The distribution of the fat was the same as in the 

 preceding experiments, the amount deposited in the aorta was not 

 greater, and tissue reaction was similarly lacking. The same 

 negative results were obtained in 2 guinea pigs receiving daily 

 subcutaneous injections of pituitrin during the feeding. 



Four guinea pigs were put on a feeding of cholesterol in oil 

 26 days after the last of 2 injections of uranium and continued on 

 this feeding for 43, 80, 83, and 88 days. Since it is believed that 

 the cholesterol kidney lesions previously described by the author 

 in rabbits are dependent on a preexisting spontaneous nephritis, 

 it was hoped in this way to obtain similar lesions from the deposit 

 of cholesterol in the interstitial lesions of chronic uranium nephritis. 

 The kidneys of all these guinea pigs showed a small amount of 

 anisotropic fat, while in only one of the above reported 9 guinea 

 pigs could any of this fat be found in the kidneys. The fat was 



