Nature of the Metabolic Products of C14-Cholesterol Excreted in Bile and Feces. ∗

Summary

Cholesterol-4-C14 was administered intravenously to normal rats and the C14 end products in feces and bile were fractionated. 1. From 4 to 10% of the total C14 in bile and from 17 to 23% of fecal C14 were recovered in the nonsaponifiable fraction which includes cholesterol, dihydrocholesterol, coprosterol, etc. 2. Little if any of the C14 in either bile or feces was recovered in the fatty acid fraction. 3. Evidence is presented to show that about 80% of the fecal C14 and about 90% of the bile C14 are present in the form of bile acids. 4. The major metabolic pathways for the nucleus carbons of cholesterol are outlined.