The origin and destiny of cholesterol in the animal organism. Part IX.—On the cholesterol content of the tissues, other than liver, of rabbits under various diets and during inanition

Abstract

In Part VIII of this series of papers, we published analyses of the livers of rabbits fed on various diets, and also of rabbits kept in a state of inanition. The results appeared to lend support to the hypothesis previously suggested with regard to herbivora, that when cells are broken down in the normal life process, their cholesterol is not excreted as a waste product, but is utilised in the formation of new cells. A function of the liver is to break down dead cells and eliminate their cholesterol in the bile. After the bile has been passed into the intestine in the process of digestion, the cholesterol is re-absorbed, possibly in the form of esters, along with the bile salts, and is carried in the blood stream to the various centres and tissues, for re-incorporation into the constitution of new cells. In this paper we give the cholesterol contents of some of the other tissues of the animals dealt with in Part VIII, in which paper we gave a full account of the methods used in extracting the tissues, and for estimating the free and ester cholesterol. That paper also contained the detailed protocols, giving the weights of the animals during the various dietetic periods and during inanition, so that it is not necessary to refer to them in detail again. The tissues examined are blood, muscle, brain, kidney, and lung. The other organs of the rabbit were too small to be dealt with in individual animals.