13 



The Origin and Destiny of Cholesterol in the Animal Organism. 

 Part X. — On the Excretion of Cholesterol by Man, when fed 

 on Various Diets. 



By G. W. Ellis and J. A. Gakdnek. 



(Communicated by Dr. A. D. Waller, F.R.S. Received September 3, — Read 



November 14, 1912.) 



(From the Physiological Laboratory of the University of London, South Kensington.) 



In earlier papers of this series we have shown that cholesterol is never 

 excreted in the normal faeces of herbivorous animals such as horses, cattle, 

 sheep, and rabbits. In the case of carnivora such as dogs and cats, provided 

 the body weight remains constant, the cholesterol excreted in the faeces can 

 be all accounted for by that naturally ingested with the food. Klein in his 

 experiments also arrived at a similar conclusion. Evidence was also brought 

 forward which rendered probable the view that, in herbivora, at any rate, 

 cholesterol is a substance which is strictly conserved in the animal economy, 

 that when the destruction of the red blood corpuscles and possibly other 

 cells takes place in the liver, their cholesterol is excreted in the bile, and that 

 the cholesterol of the bile is re-absorbed in the intestine along with the bile 

 salts, finding its way into the blood stream to be used in cell anabolism ; 

 further, that any waste of cholesterol might be made up from that taken 

 in with the food. This latter process would be limited in herbivorous 

 animals by the fact that their normal food does not contain cholesterol, but 

 isomeric substances such as phytosterol, which have to be converted into 

 cholesterol before utilisation, and in carnivorous animals by the partial, or 

 even complete, change of cholesterol into coprosterol which takes place under 

 certain dietetic conditions. In man, under normal conditions, cholesterol is 

 never excreted as such in the fasces, but always in the form of coprosterol. 

 It steemed therefore desirable to estimate the amounts of coprosterol found in 

 the faeces of man under various dietetic conditions. The opportunity of 

 making such investigations was very kindly afforded us by Dr. R. H. A. 

 Plimmer, who handed over to us the dried faeces collected during a series of 

 experiments carried out in the Physiological Institute, University College, 

 London, and published in the 'Journal of Physiology,' August 26, 1909, under 

 the title of " A Metabolism Experiment, with Special Reference to the Origin 

 of Uric Acid," by R. H. Aders Plimmer, Maxwell Dick, and Charles C. Lieb. 



The subject of the experiment was a healthy man, aged 39. The three 



