Endogenous excretion and intestinal capacity for absorption of cholesterol in the dog

Using five dogs weighing an average of 13.9 kg and fed a sterol, fat free diet, it was found that the fecal excretion of digitonin-precipitable sterol amounted to an average of 138 mg/day. The addition of oleic acid (6% by weight) to the diet did not significantly change the endogenous excretion. The average intestinal capacity to absorb exogenous cholesterol of the group of dogs, ranging in weight from 10.7 to 18 kg, was 1.05 g of cholesterol per day. When cholesterol-4-C 14 was given orally as one dose under the above dietary conditions and the feces collected for 8 days and fractionated, and the radioactivity of each fraction determined, it was found that the non-95% ethanol residue contained only a trace, the unsaponifiable material (UM) 29%, the saponifiable material (SM) 17.7% of the C 14 administered. Of the radioactivity in the UM, 80% was digitonin precipitable. In 8 days 46.7% of the administered C 14 was recovered. These results are similar to those obtained on the rat.