The absorption of cholesterol and of cholesterol oxidation products (oxidized cholesterols) was compared in lymph-cannulated
rats. We found that the lymphatic absorption of an intragastrically administered, emulsified lipid meal containing 25 mg of
cholesterol or 25 mg of oxidized cholesterols, within 24 h, was approximately 67 and 30%, respectively. The absorption rate
of individual oxidized cholesterols differed considerably and was approximately 30% for 7α-hydroxycholesterol, 42% for 7β-hydroxycholesterol,
32% for 5β-epoxycholesterol, 28% for 5α-epoxycholesterol, 15% for cholestanetriol and 12% for 7-ketocholesterol. Moreover,
cholesterol oxidation products delayed the absorption of oleic acid as triolein. Approximately 35 and 48% of cholesterol was
recovered in chylomicrons (CM) and very low density lipoprotein (VLDL), respectively. In contrast, 54 and 40% of the oxidized
cholesterols was recovered in CM and VLDL, respectively, although there was a significant difference in the distribution of
individual oxidized cholesterols. The results of the present study indicate that oxidized cholesterols are absorbed to a lesser
extent than is cholesterol, that they disturb fat absorption and that they distribute differently between lymphatic lipoproteins.