ubiquinol and cholesteryl-ester-hydroperoxide

The mechanism for the formation of active oxygen species and their reactions with antioxidants is described. The importance of the free radical chain oxidation and the singlet oxygen-dependent oxidation is suggested by a decrease in skin levels of alpha-tocopherol, ubiquinol-10, and ascorbic acid with a concomitant formation of lipid hydroperoxides during UV irradiation of murine skin, and the formation of squalene hydroperoxides in human skin upon UV exposure, respectively.

Topics: Animals; Antioxidants; Ascorbic Acid; Cholesterol Esters; Free Radicals; Phosphatidylcholines; Rats; Reactive Oxygen Species; Skin; Skin Aging; Ubiquinone; Ultraviolet Rays; Vitamin E

The pathophysiology of subarachnoid hemorrhage (SAH) may involve free radical production and lipid peroxidation. We examined plasma levels of cholesteryl ester hydroperoxides (CEOOH) and antioxidants in 25 patients with SAH, and 10 neurologic controls with lacunar stroke. Patients with SAH had significantly increased plasma levels of CEOOH, which peaked on day 5 after the ictus. Concentrations of CEOOH were significantly increased, and ascorbic acid concentrations were significantly decreased in patients who developed vasospasm compared with patients without vasospasm. Increased levels of CEOOH were associated with increased mortality and correlated with clinical outcome scales. These results implicate oxidative stress in the pathogenesis of SAH and suggest that measurements of CEOOH in plasma may be useful both prognostically as well as in monitoring therapeutic interventions.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; Biomarkers; Cholesterol Esters; Female; Humans; Lipid Peroxides; Male; Middle Aged; Oxidation-Reduction; Severity of Illness Index; Subarachnoid Hemorrhage; Ubiquinone; Uric Acid; Vitamin E