Kinetics of absorption, equilibration (or distribution), and excretion of orally and intraperitoneally administered cholesterol in the rat.

Resorption and metabolism of cholesterol administered intraperitoneally and per os have been described in the rat utilizing a technique of double isotopic labeling. Depending upon the route of administration, these parameter vary to a large degree. Alimentary cholesterol is progressively resorbed over a period of 10 hr, while the maximal blood level of cholesterol is attained after the 6th hr following intraperitoneal injection. On the other hand, cholesterol administered per os is more rapidly utilized in biliary acid synthesis than cholesterol administered intraperitoneally. In the range of concentrations utilized in this work (10-300 mug and 0.2-300 mug, respectively, administered to the rat, orally and intraperitoneally), the rate of cholesterol resorption remained constant.