Origin and Destiny of Cholesterol in the Animal Organism. 231 



on different diets on the hsemolytic action of saponin on blood might throw 

 light on the points mentioned. 



The experiments of Hausmann,* Abderhalden and Le Countf have proved 

 that whereas cholesterol and phytosterol inhibit the action of saponin, their 

 esters do not do so. More recently Windausj has sbown that the inhibitory 

 action of cholesterol and phytosterol is due to the fact that they form 

 pharmacologically inactive compounds with saponin. We therefore decided 

 to make a comparative study of the inhibitory action of the sera of rabbits 

 fed respectively on ether-extracted bran and extracted bran with cholesterol, 

 extracted bran and extracted bran with cholesterol esters, and, finally, 

 extracted bran and extracted bran with phytosterol. 



In the present paper an account is given of these experiments. 



Method of Feeding the Animals under Experiment. — In each experiment, 

 two large healthy rabbits, A and B, were fed for nine or ten days on bran 

 which had been thoroughly extracted with ether. Excess of food was placed 

 in the cages so that the animals could eat as much as they wished. In the 

 case of rabbit A, after the third day a weighed amount of cholesterol mixed 

 with a small quantity of moist extracted bran was given daily in addition, 

 care being taken that the animal ate the whole of it. The rabbit was killed 

 three or four hours after the last cholesterol meal, and the blood collected in 

 a sterile vessel. The blood was allowed to clot and was placed in the 

 refrigerator until the serum separated. The rabbit B was killed at the same 

 time and its blood collected and treated in a similar manner. Great care was 

 taken to keep the animals in good health and as far as possible under the 

 same conditions. It is also desirable not to extend the experiment over too 

 long a period lest the continued sameness of the diet should have a deleterious 

 effect. If the animals are in bad health, more especially if they waste away 

 and become emaciated, the results are entirely vitiated. This is well illus- 

 trated in the following experiment, which was commenced for another 

 purpose and only continued as a matter of curiosity. Six medium-sized 

 rabbits, weighing respectively 1*3, 1*4, 1, 1/2, 1*5, 2"3 kilogrammes, which 

 were, to begin with, in very poor condition, were fed for three weeks 

 on extracted bran. They continued in poor condition and became very 

 emaciated, and had the experiment been further prolonged would no doubt 

 have died. They yielded altogether only 190 grammes of blood. The blood 

 was analysed by the method described in an earlier paper. § 0*1799 gramme 



* ' Hofmeister's Beitr.,' vol. 6, p. 567. 

 t ; Ztschr. fur exper. Path, und Ther.,' vol. 2, p. 199. 

 \ ' Ber. d. deut. chem. Ges.,' 1909, vol. 42, No. 1, p. 238. 

 § Ibid. 



K 2 



