Abstract
Many reports on toxicological and physiological significance of oxidized cholesterols, which were detected in animals and humans, have been issued. In this manuscript, focus was put on cholesterol 5α-hydroperoxide (Ch 5α-OOH), cholesterol 7α-and 7β-hydroperoxides (Ch 7-OOH), and cholesterol 5, 6α- and 5, 6β-epoxides. Following topics on the oxidized cholesterols were introduced : 1) A highly sensitive bioanalysis method for the hydroperoxides was established with an HPLC system equipped with a chemiluminescence detector, 2) Ch 7-OOH in rat skin is a good marker for aging, 3) Ch 7-OOH is a good marker for free radical dependent-lipid peroxidation in vivo, 4) Evidence for occurrence of the labile activated oxygen species, singlet oxygen, in a living animal was presented by detection of Ch 5α-OOH in rats pretreated with oral doses of pheophorbide a and subsequent visible light irradiation, 5) A phospholipid peroxide dependent stereochemical mechanism for the formation of cholesterol 5, 6α-epoxide and 5, 6β-epoxide, which were suggested as systemic carcinogens, was introduced.
