Observations concerning the production and excretion of cholesterol in mammals. X. Factors affecting the absorption and fate of ingested cholesterol.

The absorption of oral cholesterol by rats was followed directly by analyses of the thoracic lymph and indirectly by calculating the deficit of fecal cholesterol under the amount fed. The two methods checked within about 20 per cent, with fecal analyses indicating the greater absorption. The absorbed cholesterol was found to be deposited in the liver, only very minor quantities being found in other organs or plasma. Bile is necessary for normal absorption of cholesterol, although very small amounts are absorbed even in its absence. Excess oral cholic acid increases the absorption of cholesterol by otherwise normal animals. The rat absorbs about 47 per cent of a single 50 mg. dose of cholesterol and about 34 per cent of a 100 mg. dose.