Cholesterol hydroperoxides in erythrocyte membranes of alcoholic patients.

Evidence for the presence of 5alpha-hydroperoxycholest-6-en-3beta-ol (cholesterol 5alpha-hydroperoxide, Ch 5alpha-OOH) and 7alpha- and 7beta-hydroperoxycholest-5-en-3beta-ols (cholesterol 7-hydroperoxides: Ch 7alpha-OOH and Ch 7beta-OOH, respectively) in human erythrocyte membrane was found. Blood samples were collected from alcoholic patients and healthy volunteers (controls), and their cholesterol hydroperoxides were analyzed by high-performance liquid chromatography postcolumn chemiluminescence and roughly identified by liquid chromatography-mass spectrometry. Ch 7alpha-OOH and Ch 7beta-OOH were present in each sample, being significantly higher in alcoholic samples than in control samples. Ch 5alpha-OOH was present in some alcoholic samples, but not in the control ones. The accumulation of cholesterol hydroperoxides suggests enhanced lipid peroxidation by active oxygen species and/or a reduced elimination system for lipid peroxide in alcoholic patients.