Sterol metabolism. XXX. Cholesterol 25-hydroperoxide metabolism.
ABSTRACT The metabolism of cholesterol 25-hydroperoxide by subcellular fractions of rat and calf liver and of rat kidney was examined. The sole metabolic transformation observed was the reduction of the 25-hydroperoxide to the corresponding 25-alcohol 5-cholestene-3β,25-diol. No evidence of enzymic rearrangement of the 25-hydroperoxide to vicinal diol products was adduced. Neither cholesterol 25-hydroperoxide nor 5-cholestene-3β,25-diol was converted by rat liver homogenates to bile acids. Attempts to demonstrate cholesterol 25-hydroperoxide as a putative intermediate in the biosynthesis of bile acids from cholesterol in rat liver homogenates and calf liver microsomes by trapping techniques were unsuccessful. It was concluded that cholesterol 25-hydroperoxide is not implicated in cholesterol metabolism in liver or kidney tissues.